U.S. patent application number 17/356613 was filed with the patent office on 2021-10-14 for methods, apparatus and systems for gyroscope scale calibration.
The applicant listed for this patent is IDHL Holdings, Inc.. Invention is credited to Bryan A. Cook, Yun Li, Mark Turner.
Application Number | 20210318142 17/356613 |
Document ID | / |
Family ID | 1000005669074 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210318142 |
Kind Code |
A1 |
Cook; Bryan A. ; et
al. |
October 14, 2021 |
METHODS, APPARATUS AND SYSTEMS FOR GYROSCOPE SCALE CALIBRATION
Abstract
Methods, apparatus, and systems for estimating and calibrating a
gyroscope's scale using a magnetometer mounted on the same device
by rotating the device about an axis multiple times; and, during
the first rotation, storing the magnetometer magnetic field reading
and a heading (from integration of the gyroscope readings) at each
of a plurality of angular reference points; then, during each
subsequent rotation, determining magnetometer/gyroscope-heading
output pairs for which the magnetometer output matches the
magnetometer reading corresponding to one of the reference points,
thereby indicating that the device has reached the same heading as
the matching reference point; then, for each matching output sample
pair, using that magnetometer/gyroscope-heading output sample pair
to update the gyroscope scale factor for the corresponding angular
reference point; and averaging those scale estimates to generate a
final gyroscope scale factor estimate.
Inventors: |
Cook; Bryan A.; (Silver
Spring, MD) ; Li; Yun; (Clarksburg, MD) ;
Turner; Mark; (Ijamsville, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IDHL Holdings, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
1000005669074 |
Appl. No.: |
17/356613 |
Filed: |
June 24, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16473321 |
Jun 25, 2019 |
11079252 |
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PCT/US2018/012608 |
Jan 5, 2018 |
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17356613 |
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62443279 |
Jan 6, 2017 |
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62557728 |
Sep 12, 2017 |
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62580764 |
Nov 2, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01P 15/14 20130101;
G01C 21/165 20130101; G01C 25/005 20130101 |
International
Class: |
G01C 25/00 20060101
G01C025/00; G01C 21/16 20060101 G01C021/16; G01P 15/14 20060101
G01P015/14 |
Claims
1-30. (canceled)
31. A method, implemented in a device having a sensor, to calibrate
a scale of the sensor, comprising: receiving, by the device, a
first input indicating that the device is in a first angular
position, as a start position; providing, by the device, a first
indication that the device is ready to be moved to another position
or a final position; measuring, by the device, a plurality of
output values of the sensor, after the first indication is
provided; receiving, by the device, a second input indicating that
the device is in a second, preconfigured angular position, relative
to the start position, as the final position; estimating, by the
device, the scale of the sensor using the plurality of output
values measured while the device moved between the start position
and the final position; and providing, by the device, a second
indication of whether the estimate of the scale of the sensor is
within a predefined threshold.
32. The method of claim 31, wherein the providing of the first
indication includes presenting, via a display or a light, the first
indication that the device is ready to be moved to the other
position or the final position, as an indication that the device is
ready for calibration.
33. The method of claim 32, wherein the providing of the second
indication includes presenting, via the display or the light, the
second indication indicating whether the sensor satisfies the
predefined threshold, as a calibration threshold.
34. The method of claim 31, wherein the estimating of the scale of
the sensor includes: averaging one or more output values of the
sensor taken while the device is at the start position;
determining, by the device, a zero rate offset (ZRO) from the
averaged one or more output values of the sensor taken while the
device is at the start position; and compensating, by the device,
for the ZRO in the estimation of the scale of the sensor.
35. The method of claim 31, wherein the start position is a
position such that the device is in a docking station.
36. The method of claim 35, further comprising undocking the device
such that the device is undocked from the docking station while the
device was moving between the start position and the final
position.
37. The method of claim 36, further comprising redocking the device
such that estimating of the scale of the sensor is conditioned on
the device being redocked in the docking station.
38. The method of claim 31, further comprising: sending, by the
device, any of: (1) data associated with the output values of the
sensor measured while the device moved between the start position
and the final position; (2) estimation information in accordance
with the estimating of the scale of the sensor; (3) one or more
error codes indicating a type of error associated with a scale
estimation operation; or (4) a calibration record.
39. A device, having a sensor, comprising: an interface configured
to: receive a first input indicating that the device is in a first
angular position, as a start position, and provide a first
indication that the device is ready to be moved to another position
or a final position; and a processor configured to: measure a
plurality of output values of the sensor, after the first
indication is provided, and estimate the scale of the sensor using
the plurality of output values measured while the device moved
between the start position and the final position, wherein the
interface is configured to: receive a second input indicating that
the device is in a second, preconfigured angular position, relative
to the start position, as the final position, and provide a second
indication indicating whether the estimate of the scale of the
sensor is within a predefined threshold.
40. The device of claim 39, wherein the interface includes a
display or light configured to: present, to an external entity, the
first indication that the device is ready to be moved to the other
position or the final position, as an indication that the device is
ready for calibration; and present, to the external entity, the
second indication indicating whether the estimate of the scale of
the sensor is within the predefined threshold.
41. The device of claim 39, wherein the processor is configured to:
average one or more output values taken while the device is at the
start position; determine a zero rate offset (ZRO) from the
averaged one or more output values taken while the device is at the
start position; and compensate for the ZRO in the estimation of the
scale of the sensor.
42. The device of claim 39, wherein the interface includes a
transmit unit configured to send any of: (1) data associated with
the output values measured while the device moved between the start
position and the final position; (2) estimation information in
accordance with the estimation of the scale of the sensor; (3) one
or more error codes indicating a type of error associated with a
scale estimation operation; or (4) a calibration record.
43. The device of claim 39, wherein the start position is a
position such that the device is in a docking station.
44. The device of claim 43, further comprising; a motor unit
configured to: undock the device from the docking station; move the
device between the start position and the final position; and
redock the device in the docking station.
45. The device of claim 44, wherein the processor is configured to
estimate the scale of the sensor on condition that the device is
redocked in the docking station.
46. A device having a sensor, comprising: a transmit/receive unit
configured to: send a first indication that the device is ready to
be moved to another position or a final position after being
positioned in a first angular position, as a start position, and
receive a first input indicating that the device is in a second,
preconfigured angular position, relative to the start position, as
the final position; and a processor configured to estimate the
scale of the sensor using a plurality of output values of the
sensor measured while the device moved between the start position
and the final position.
47. The device of claim 46, wherein the transmit/receive unit is
configured to provide a second indication of whether the estimate
of the scale of the sensor is within a predefined threshold.
48. The device of claim 46, wherein the transmit/receive unit is
configured to receive another input indicating that the device is
in the first angular position.
49. The device of claim 44, wherein the processor is configured to
measure a plurality of output values of the sensor, after the first
indication is sent.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Patent Application No. 62/580,764, filed Nov. 2, 2017, U.S.
Provisional Patent Application No. 62/557,728, filed Sep. 12, 2017
and U.S. Provisional Patent Application No. 62/443,279, filed Jan.
6, 2017, the contents of each of which are hereby incorporated
herein by reference as if fully set forth.
FIELD
[0002] Embodiments disclosed herein generally relate to sensor
calibration and, for example to methods, apparatus and systems for
gyroscope scale calibration.
RELATED
[0003] Gyroscopes may be calibrated, for example to enable
measurement of angular velocity.
SUMMARY
[0004] According to certain embodiments, a device, e.g., a robotic
vacuum cleaner, an Inertial Measurement Unit (IMU) and/or a
Wireless Transmit/Receive unit (WTRU), may include at least one
gyroscope and at least one magnetometer, wherein one or more
readings taken by the magnetometer may be used to compensate for at
least one parameter associated with the gyroscope.
[0005] According to certain embodiments, a scale of a gyroscope may
be calibrated using plural magnetic field measurements (e.g., in a
range of about 10 to 12 field measurements) acquired during one or
more successive rotations (in a range of about 3 to 5 or more
rotations of 360.degree.) of the gyroscope and magnetometer at
substantially the same angular positions.
[0006] According to certain embodiments, a scale of a gyroscope may
be calibrated on-board the mobile device (e.g., the robotic vacuum
cleaner, the WTRU and/or the IMU, among others), for example using
a calibration device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A more detailed understanding may be had from the detailed
description below, given by way of example in conjunction with
drawings appended hereto. Figures in description, are examples. As
such, the Figures and the detailed description are not to be
considered limiting, and other equally effective examples are
possible and likely. Furthermore, like reference numerals in the
figures indicate like elements, and wherein:
[0008] FIG. 1A is a system diagram illustrating an example
communications system in which one or more disclosed embodiments
may be implemented;
[0009] FIG. 1B is a system diagram illustrating an example wireless
transmit/receive unit (WTRU) that may be used within the
communications system illustrated in FIG. 1A according to an
embodiment;
[0010] FIG. 1C is a system diagram illustrating an example radio
access network (RAN) and an example core network (CN) that may be
used within the communications system illustrated in FIG. 1A
according to an embodiment;
[0011] FIG. 1D is a system diagram illustrating a further example
RAN and a further example CN that may be used within the
communications system illustrated in FIG. 1A according to an
embodiment;
[0012] FIG. 2 is a block diagram of a robotic apparatus/appliance
(RAA);
[0013] FIG. 3 is a diagram illustrating representative hardware
architecture to execute various calibration procedures according to
representative embodiments;
[0014] FIGS. 4A and 4B are graphs illustrating a calibration
procedure in a first environment;
[0015] FIGS. 5A and 5B are another set of graphs illustrating the
calibration procedure of FIGS. 3A and 3B in a second environment
(e.g., a more disruptive magnetic field environment);
[0016] FIGS. 6A and 6B are another set of graphs illustrating the
calibration procedure of FIGS. 3A and 3B in a third environment
(e.g., an even more disruptive magnetic field environment);
[0017] FIG. 7 is a flow diagram illustrating a representative
calibration procedure using a magnetometer;
[0018] FIG. 8 is a diagram illustrating a representative
calibration procedure;
[0019] FIG. 9 is a diagram illustrating another representative
calibration procedure;
[0020] FIG. 10 is a diagram illustrating the representative
calibration procedure of FIG. 9 for a device rotated relative to a
starting angular position using a calibration device;
[0021] FIG. 11 is a diagram illustrating a further representative
calibration procedure for a device using the inside surfaces of an
N-side polygon calibration device;
[0022] FIG. 12 is a diagram illustrating an additional
representative calibration procedure for the device using the
outside surfaces of the N-side polygon calibration device;
[0023] FIG. 13A is a diagram illustrating a top view of a device
fixture;
[0024] FIG. 13B is a diagram illustrating a side view of the device
fixture of FIG. 13A;
[0025] FIG. 13C is a diagram illustrating a top view of a test
device;
[0026] FIG. 13D is a diagram illustrating a side view of the test
device;
[0027] FIG. 14 is a diagram illustrating a docking operation to
show another calibration procedure;
[0028] FIG. 15 is a flowchart of a representative method to
estimate a gyroscope scale factor;
[0029] FIG. 16 is a flowchart of another representative method to
estimate a gyroscope scale;
[0030] FIG. 17 is a flowchart of an additional representative
method to estimate a gyroscope scale; and
[0031] FIG. 18 is a flowchart of a further representative method to
estimate a gyroscope scale.
DETAILED DESCRIPTION
Example Networks for Implementation of the Embodiments
[0032] As previously noted, in addition to robotic vacuum cleaners,
the invention may be implemented in a robotic vehicle, car, IoT
gear, any device that moves, or a WTRU or other communication
device, which, in turn, may be used in a communication network. The
following section provides a description of some exemplary WTRUs
and/or other communication devices and networks in which they may
be incorporated.
[0033] FIG. 1A is a diagram illustrating an example communications
system 100 in which one or more disclosed embodiments may be
implemented. The communications system 100 may be a multiple access
system that provides content, such as voice, data, video,
messaging, broadcast, etc., to multiple wireless users. The
communications system 100 may enable multiple wireless users to
access such content through the sharing of system resources,
including wireless bandwidth. For example, the communications
systems 100 may employ one or more channel access methods, such as
code division multiple access (CDMA), time division multiple access
(TDMA), frequency division multiple access (FDMA), orthogonal FDMA
(OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word
DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM),
resource block-filtered OFDM, filter bank multicarrier (FBMC), and
the like.
[0034] As shown in FIG. 1A, the communications system 100 may
include wireless transmit/receive units (WTRUs) 102a, 102b, 102c,
102d, a RAN 104/113, a CN 106/115, a public switched telephone
network (PSTN) 108, the Internet 110, and other networks 112,
though it will be appreciated that the disclosed embodiments
contemplate any number of WTRUs, base stations, networks, and/or
network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be
any type of device configured to operate and/or communicate in a
wireless environment. By way of example, the WTRUs 102a, 102b,
102c, 102d, any of which may be referred to as a "station" and/or a
"STA", may be configured to transmit and/or receive wireless
signals and may include a user equipment (UE), a mobile station, a
fixed or mobile subscriber unit, a subscription-based unit, a
pager, a cellular telephone, a personal digital assistant (PDA), a
smartphone, a laptop, a netbook, a personal computer, a wireless
sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT)
device, a watch or other wearable, a head-mounted display (HMD), a
vehicle, a drone, a medical device and applications (e.g., remote
surgery), an industrial device and applications (e.g., a robot
and/or other wireless devices operating in an industrial and/or an
automated processing chain contexts), a consumer electronics
device, a device operating on commercial and/or industrial wireless
networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d
may be interchangeably referred to as a UE.
[0035] The communications systems 100 may also include a base
station 114a and/or a base station 114b. Each of the base stations
114a, 114b may be any type of device configured to wirelessly
interface with at least one of the WTRUs 102a, 102b, 102c, 102d to
facilitate access to one or more communication networks, such as
the CN 106/115, the Internet 110, and/or the other networks 112. By
way of example, the base stations 114a, 114b may be a base
transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a
Home eNode B, a gNB, a NR Node B, a site controller, an access
point (AP), a wireless router, and the like. While the base
stations 114a, 114b are each depicted as a single element, it will
be appreciated that the base stations 114a, 114b may include any
number of interconnected base stations and/or network elements.
[0036] The base station 114a may be part of the RAN 104/113, which
may also include other base stations and/or network elements (not
shown), such as a base station controller (BSC), a radio network
controller (RNC), relay nodes, etc. The base station 114a and/or
the base station 114b may be configured to transmit and/or receive
wireless signals on one or more carrier frequencies, which may be
referred to as a cell (not shown). These frequencies may be in
licensed spectrum, unlicensed spectrum, or a combination of
licensed and unlicensed spectrum. A cell may provide coverage for a
wireless service to a specific geographical area that may be
relatively fixed or that may change over time. The cell may further
be divided into cell sectors. For example, the cell associated with
the base station 114a may be divided into three sectors. Thus, in
one embodiment, the base station 114a may include three
transceivers, i.e., one for each sector of the cell. In an
embodiment, the base station 114a may employ multiple-input
multiple output (MIMO) technology and may utilize multiple
transceivers for each sector of the cell. For example, beamforming
may be used to transmit and/or receive signals in desired spatial
directions.
[0037] The base stations 114a, 114b may communicate with one or
more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116,
which may be any suitable wireless communication link (e.g., radio
frequency (RF), microwave, centimeter wave, micrometer wave,
infrared (IR), ultraviolet (UV), visible light, etc.). The air
interface 116 may be established using any suitable radio access
technology (RAT).
[0038] More specifically, as noted above, the communications system
100 may be a multiple access system and may employ one or more
channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA,
and the like. For example, the base station 114a in the RAN 104/113
and the WTRUs 102a, 102b, 102c may implement a radio technology
such as Universal Mobile Telecommunications System (UMTS)
Terrestrial Radio Access (UTRA), which may establish the air
interface 115/116/117 using wideband CDMA (WCDMA). WCDMA may
include communication protocols such as High-Speed Packet Access
(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed
Downlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet
Access (HSUPA).
[0039] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as Evolved UMTS
Terrestrial Radio Access (E-UTRA), which may establish the air
interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced
(LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).
[0040] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as NR Radio
Access, which may establish the air interface 116 using New Radio
(NR).
[0041] In an embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement multiple radio access technologies. For
example, the base station 114a and the WTRUs 102a, 102b, 102c may
implement LTE radio access and NR radio access together, for
instance using dual connectivity (DC) principles. Thus, the air
interface utilized by WTRUs 102a, 102b, 102c may be characterized
by multiple types of radio access technologies and/or transmissions
sent to/from multiple types of base stations (e.g., a eNB and a
gNB).
[0042] In other embodiments, the base station 114a and the WTRUs
102a, 102b, 102c may implement radio technologies such as IEEE
802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e.,
Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,
CDMA2000 1.times., CDMA2000 EV-DO, Interim Standard 2000 (IS-2000),
Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global
System for Mobile communications (GSM), Enhanced Data rates for GSM
Evolution (EDGE), GSM EDGE (GERAN), and the like.
[0043] The base station 114b in FIG. 1A may be a wireless router,
Home Node B, Home eNode B, or access point, for example, and may
utilize any suitable RAT for facilitating wireless connectivity in
a localized area, such as a place of business, a home, a vehicle, a
campus, an industrial facility, an air corridor (e.g., for use by
drones), a roadway, and the like. In one embodiment, the base
station 114b and the WTRUs 102c, 102d may implement a radio
technology such as IEEE 802.11 to establish a wireless local area
network (WLAN). In an embodiment, the base station 114b and the
WTRUs 102c, 102d may implement a radio technology such as IEEE
802.15 to establish a wireless personal area network (WPAN). In yet
another embodiment, the base station 114b and the WTRUs 102c, 102d
may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,
LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As
shown in FIG. 1A, the base station 114b may have a direct
connection to the Internet 110. Thus, the base station 114b may not
be required to access the Internet 110 via the CN 106/115.
[0044] The RAN 104/113 may be in communication with the CN 106/115,
which may be any type of network configured to provide voice, data,
applications, and/or voice over internet protocol (VoIP) services
to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may
have varying quality of service (QoS) requirements, such as
differing throughput requirements, latency requirements, error
tolerance requirements, reliability requirements, data throughput
requirements, mobility requirements, and the like. The CN 106/115
may provide call control, billing services, mobile location-based
services, pre-paid calling, Internet connectivity, video
distribution, etc., and/or perform high-level security functions,
such as user authentication. Although not shown in FIG. 1A, it will
be appreciated that the RAN 104/113 and/or the CN 106/115 may be in
direct or indirect communication with other RANs that employ the
same RAT as the RAN 104/113 or a different RAT. For example, in
addition to being connected to the RAN 104/113, which may be
utilizing a NR radio technology, the CN 106/115 may also be in
communication with another RAN (not shown) employing a GSM, UMTS,
CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.
[0045] The CN 106/115 may also serve as a gateway for the WTRUs
102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110,
and/or the other networks 112. The PSTN 108 may include
circuit-switched telephone networks that provide plain old
telephone service (POTS). The Internet 110 may include a global
system of interconnected computer networks and devices that use
common communication protocols, such as the transmission control
protocol (TCP), user datagram protocol (UDP) and/or the internet
protocol (IP) in the TCP/IP internet protocol suite. The networks
112 may include wired and/or wireless communications networks owned
and/or operated by other service providers. For example, the
networks 112 may include another CN connected to one or more RANs,
which may employ the same RAT as the RAN 104/113 or a different
RAT.
[0046] Some or all of the WTRUs 102a, 102b, 102c, 102d in the
communications system 100 may include multi-mode capabilities
(e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple
transceivers for communicating with different wireless networks
over different wireless links) For example, the WTRU 102c shown in
FIG. 1A may be configured to communicate with the base station
114a, which may employ a cellular-based radio technology, and with
the base station 114b, which may employ an IEEE 802 radio
technology.
[0047] FIG. 1B is a system diagram illustrating an example WTRU
102. As shown in FIG. 1B, the WTRU 102 may include a processor 118,
a transceiver 120, a transmit/receive element 122, a
speaker/microphone 124, a keypad 126, a display/touchpad 128,
non-removable memory 130, removable memory 132, a power source 134,
a global positioning system (GPS) chipset 136, and/or other
peripherals 138, among others. It will be appreciated that the WTRU
102 may include any sub-combination of the foregoing elements while
remaining consistent with an embodiment.
[0048] The processor 118 may be a general purpose processor, a
special purpose processor, a conventional processor, a digital
signal processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Arrays (FPGAs) circuits, any other type of
integrated circuit (IC), a state machine, and the like. The
processor 118 may perform signal coding, data processing, power
control, input/output processing, and/or any other functionality
that enables the WTRU 102 to operate in a wireless environment. The
processor 118 may be coupled to the transceiver 120, which may be
coupled to the transmit/receive element 122. While FIG. 1B depicts
the processor 118 and the transceiver 120 as separate components,
it will be appreciated that the processor 118 and the transceiver
120 may be integrated together in an electronic package or
chip.
[0049] The transmit/receive element 122 may be configured to
transmit signals to, or receive signals from, a base station (e.g.,
the base station 114a) over the air interface 116. For example, in
one embodiment, the transmit/receive element 122 may be an antenna
configured to transmit and/or receive RF signals. In an embodiment,
the transmit/receive element 122 may be an emitter/detector
configured to transmit and/or receive IR, UV, or visible light
signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and/or
receive both RF and light signals. It will be appreciated that the
transmit/receive element 122 may be configured to transmit and/or
receive any combination of wireless signals.
[0050] Although the transmit/receive element 122 is depicted in
FIG. 1B as a single element, the WTRU 102 may include any number of
transmit/receive elements 122. More specifically, the WTRU 102 may
employ MIMO technology. Thus, in one embodiment, the WTRU 102 may
include two or more transmit/receive elements 122 (e.g., multiple
antennas) for transmitting and receiving wireless signals over the
air interface 116.
[0051] The transceiver 120 may be configured to modulate the
signals that are to be transmitted by the transmit/receive element
122 and to demodulate the signals that are received by the
transmit/receive element 122. As noted above, the WTRU 102 may have
multi-mode capabilities. Thus, the transceiver 120 may include
multiple transceivers for enabling the WTRU 102 to communicate via
multiple RATs, such as NR and IEEE 802.11, for example.
[0052] The processor 118 of the WTRU 102 may be coupled to, and may
receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 130 and/or the removable memory 132. The
non-removable memory 130 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WTRU 102, such as on a server or a home
computer (not shown).
[0053] The processor 118 may receive power from the power source
134, and may be configured to distribute and/or control the power
to the other components in the WTRU 102. The power source 134 may
be any suitable device for powering the WTRU 102. For example, the
power source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and
the like.
[0054] The processor 118 may also be coupled to the GPS chipset
136, which may be configured to provide location information (e.g.,
longitude and latitude) regarding the current location of the WTRU
102. In addition to, or in lieu of, the information from the GPS
chipset 136, the WTRU 102 may receive location information over the
air interface 116 from a base station (e.g., base stations 114a,
114b) and/or determine its location based on the timing of the
signals being received from two or more nearby base stations. It
will be appreciated that the WTRU 102 may acquire location
information by way of any suitable location-determination method
while remaining consistent with an embodiment.
[0055] The processor 118 may further be coupled to other
peripherals 138, which may include one or more software and/or
hardware modules that provide additional features, functionality
and/or wired or wireless connectivity. For example, the peripherals
138 may include an accelerometer, an e-compass, a satellite
transceiver, a digital camera (for photographs and/or video), a
universal serial bus (USB) port, a vibration device, a television
transceiver, a hands free headset, a Bluetooth.RTM. module, a
frequency modulated (FM) radio unit, a digital music player, a
media player, a video game player module, an Internet browser, a
Virtual Reality and/or Augmented Reality (VR/AR) device, an
activity tracker, and the like. The peripherals 138 may include one
or more sensors, the sensors may be one or more of a gyroscope, an
accelerometer, a hall effect sensor, a magnetometer, an orientation
sensor, a proximity sensor, a temperature sensor, a time sensor; a
geolocation sensor; an altimeter, a light sensor, a touch sensor, a
magnetometer, a barometer, a gesture sensor, a biometric sensor,
and/or a humidity sensor.
[0056] The processor 118 of the WTRU 102 may operatively
communicate with various peripherals 138 including, for example,
any of: the one or more accelerometers, the one or more gyroscopes,
the USB port, other communication interfaces/ports, the display
and/or other visual/audio indicators to implement representative
embodiments disclosed herein.
[0057] The WTRU 102 may include a full duplex radio for which
transmission and reception of some or all of the signals (e.g.,
associated with particular subframes for both the UL (e.g., for
transmission) and downlink (e.g., for reception) may be concurrent
and/or simultaneous. The full duplex radio may include an
interference management unit to reduce and or substantially
eliminate self-interference via either hardware (e.g., a choke) or
signal processing via a processor (e.g., a separate processor (not
shown) or via processor 118). In an embodiment, the WTRU102 may
include a half-duplex radio for which transmission and reception of
some or all of the signals (e.g., associated with particular
subframes for either the UL (e.g., for transmission) or the
downlink (e.g., for reception)).
[0058] FIG. 1C is a system diagram illustrating the RAN 104 and the
CN 106 according to an embodiment. As noted above, the RAN 104 may
employ an E-UTRA radio technology to communicate with the WTRUs
102a, 102b, 102c over the air interface 116. The RAN 104 may also
be in communication with the CN 106.
[0059] The RAN 104 may include eNode Bs 160a, 160b, 160c, though it
will be appreciated that the RAN 104 may include any number of
eNode Bs while remaining consistent with an embodiment. The eNode
Bs 160a, 160b, 160c may each include one or more transceivers for
communicating with the WTRUs 102a, 102b, 102c over the air
interface 116. In one embodiment, the eNode Bs 160a, 160b, 160c may
implement MIMO technology. Thus, the eNode B 160a, for example, may
use multiple antennas to transmit wireless signals to, and/or
receive wireless signals from, the WTRU 102a.
[0060] Each of the eNode Bs 160a, 160b, 160c may be associated with
a particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the UL and/or DL, and the like. As shown in FIG. 1C, the
eNode Bs 160a, 160b, 160c may communicate with one another over an
X2 interface.
[0061] The CN 106 shown in FIG. 1C may include a mobility
management entity (MME) 162, a serving gateway (SGW) 164, and a
packet data network (PDN) gateway (or PGW) 166. While each of the
foregoing elements are depicted as part of the CN 106, it will be
appreciated that any of these elements may be owned and/or operated
by an entity other than the CN operator.
[0062] The MME 162 may be connected to each of the eNode Bs 160a,
160b, 160c in the RAN 104 via an S1 interface and may serve as a
control node. For example, the MME 162 may be responsible for
authenticating users of the WTRUs 102a, 102b, 102c, bearer
activation/deactivation, selecting a particular serving gateway
during an initial attach of the WTRUs 102a, 102b, 102c, and the
like. The MME 162 may provide a control plane function for
switching between the RAN 104 and other RANs (not shown) that
employ other radio technologies, such as GSM and/or WCDMA.
[0063] The SGW 164 may be connected to each of the eNode Bs 160a,
160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may
generally route and forward user data packets to/from the WTRUs
102a, 102b, 102c. The SGW 164 may perform other functions, such as
anchoring user planes during inter-eNode B handovers, triggering
paging when DL data is available for the WTRUs 102a, 102b, 102c,
managing and storing contexts of the WTRUs 102a, 102b, 102c, and
the like.
[0064] The SGW 164 may be connected to the PGW 166, which may
provide the WTRUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between the WTRUs 102a, 102b, 102c and IP-enabled devices.
[0065] The CN 106 may facilitate communications with other
networks. For example, the CN 106 may provide the WTRUs 102a, 102b,
102c with access to circuit-switched networks, such as the PSTN
108, to facilitate communications between the WTRUs 102a, 102b,
102c and traditional land-line communications devices. For example,
the CN 106 may include, or may communicate with, an IP gateway
(e.g., an IP multimedia subsystem (IMS) server) that serves as an
interface between the CN 106 and the PSTN 108. In addition, the CN
106 may provide the WTRUs 102a, 102b, 102c with access to the other
networks 112, which may include other wired and/or wireless
networks that are owned and/or operated by other service
providers.
[0066] Although the WTRU is described in FIGS. 1A-1D as a wireless
terminal, it is contemplated that in certain representative
embodiments that such a terminal may use (e.g., temporarily or
permanently) wired communication interfaces with the communication
network.
[0067] In representative embodiments, the other network 112 may be
a WLAN.
[0068] A WLAN in Infrastructure Basic Service Set (BSS) mode may
have an Access Point (AP) for the BSS and one or more stations
(STAs) associated with the AP. The AP may have an access or an
interface to a Distribution System (DS) or another type of
wired/wireless network that carries traffic in to and/or out of the
BSS. Traffic to STAs that originates from outside the BSS may
arrive through the AP and may be delivered to the STAs. Traffic
originating from STAs to destinations outside the BSS may be sent
to the AP to be delivered to respective destinations. Traffic
between STAs within the BSS may be sent through the AP, for
example, where the source STA may send traffic to the AP and the AP
may deliver the traffic to the destination STA. The traffic between
STAs within a BSS may be considered and/or referred to as
peer-to-peer traffic. The peer-to-peer traffic may be sent between
(e.g., directly between) the source and destination STAs with a
direct link setup (DLS). In certain representative embodiments, the
DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A
WLAN using an Independent BSS (IBSS) mode may not have an AP, and
the STAs (e.g., all of the STAs) within or using the IBSS may
communicate directly with each other. The IBSS mode of
communication may sometimes be referred to herein as an "ad-hoc"
mode of communication.
[0069] When using the 802.11ac infrastructure mode of operation or
a similar mode of operations, the AP may transmit a beacon on a
fixed channel, such as a primary channel. The primary channel may
be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set
width via signaling. The primary channel may be the operating
channel of the BSS and may be used by the STAs to establish a
connection with the AP. In certain representative embodiments,
Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
may be implemented, for example in in 802.11 systems. For CSMA/CA,
the STAs (e.g., every STA), including the AP, may sense the primary
channel. If the primary channel is sensed/detected and/or
determined to be busy by a particular STA, the particular STA may
back off. One STA (e.g., only one station) may transmit at any
given time in a given BSS.
[0070] High Throughput (HT) STAs may use a 40 MHz wide channel for
communication, for example, via a combination of the primary 20 MHz
channel with an adjacent or nonadjacent 20 MHz channel to form a 40
MHz wide channel.
[0071] Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz,
80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz,
channels may be formed by combining contiguous 20 MHz channels. A
160 MHz channel may be formed by combining 8 contiguous 20 MHz
channels, or by combining two non-contiguous 80 MHz channels, which
may be referred to as an 80+80 configuration. For the 80+80
configuration, the data, after channel encoding, may be passed
through a segment parser that may divide the data into two streams.
Inverse Fast Fourier Transform (IFFT) processing, and time domain
processing, may be done on each stream separately. The streams may
be mapped on to the two 80 MHz channels, and the data may be
transmitted by a transmitting STA. At the receiver of the receiving
STA, the above described operation for the 80+80 configuration may
be reversed, and the combined data may be sent to the Medium Access
Control (MAC).
[0072] Sub 1 GHz modes of operation are supported by 802.11af and
802.11ah. The channel operating bandwidths, and carriers, are
reduced in 802.11af and 802.11ah relative to those used in 802.11n,
and 802.11ac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths
in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz,
2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum.
According to a representative embodiment, 802.11ah may support
Meter Type Control/Machine-Type Communications, such as MTC devices
in a macro coverage area. MTC devices may have certain
capabilities, for example, limited capabilities including support
for (e.g., only support for) certain and/or limited bandwidths. The
MTC devices may include a battery with a battery life above a
threshold (e.g., to maintain a very long battery life).
[0073] WLAN systems, which may support multiple channels, and
channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and
802.11ah, include a channel which may be designated as the primary
channel. The primary channel may have a bandwidth equal to the
largest common operating bandwidth supported by all STAs in the
BSS. The bandwidth of the primary channel may be set and/or limited
by a STA, from among all STAs in operating in a BSS, which supports
the smallest bandwidth operating mode. In the example of 802.11ah,
the primary channel may be 1 MHz wide for STAs (e.g., MTC type
devices) that support (e.g., only support) a 1 MHz mode, even if
the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16
MHz, and/or other channel bandwidth operating modes. Carrier
sensing and/or Network Allocation Vector (NAV) settings may depend
on the status of the primary channel. If the primary channel is
busy, for example, due to a STA (which supports only a 1 MHz
operating mode), transmitting to the AP, the entire available
frequency bands may be considered busy even though a majority of
the frequency bands remains idle and may be available.
[0074] In the United States, the available frequency bands, which
may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the
available frequency bands are from 917.5 MHz to 923.5 MHz. In
Japan, the available frequency bands are from 916.5 MHz to 927.5
MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz
depending on the country code.
[0075] FIG. 1D is a system diagram illustrating the RAN 113 and the
CN 115 according to an embodiment. As noted above, the RAN 113 may
employ an NR radio technology to communicate with the WTRUs 102a,
102b, 102c over the air interface 116. The RAN 113 may also be in
communication with the CN 115.
[0076] The RAN 113 may include gNBs 180a, 180b, 180c, though it
will be appreciated that the RAN 113 may include any number of gNBs
while remaining consistent with an embodiment. The gNBs 180a, 180b,
180c may each include one or more transceivers for communicating
with the WTRUs 102a, 102b, 102c over the air interface 116. In one
embodiment, the gNBs 180a, 180b, 180c may implement MIMO
technology. For example, gNBs 180a, 108b may utilize beamforming to
transmit signals to and/or receive signals from the gNBs 180a,
180b, 180c. Thus, the gNB 180a, for example, may use multiple
antennas to transmit wireless signals to, and/or receive wireless
signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b,
180c may implement carrier aggregation technology. For example, the
gNB 180a may transmit multiple component carriers to the WTRU 102a
(not shown). A subset of these component carriers may be on
unlicensed spectrum while the remaining component carriers may be
on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c
may implement Coordinated Multi-Point (CoMP) technology. For
example, WTRU 102a may receive coordinated transmissions from gNB
180a and gNB 180b (and/or gNB 180c).
[0077] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a,
180b, 180c using transmissions associated with a scalable
numerology. For example, the OFDM symbol spacing and/or OFDM
subcarrier spacing may vary for different transmissions, different
cells, and/or different portions of the wireless transmission
spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs
180a, 180b, 180c using subframe or transmission time intervals
(TTIs) of various or scalable lengths (e.g., containing varying
number of OFDM symbols and/or lasting varying lengths of absolute
time).
[0078] The gNBs 180a, 180b, 180c may be configured to communicate
with the WTRUs 102a, 102b, 102c in a standalone configuration
and/or a non-standalone configuration. In the standalone
configuration, WTRUs 102a, 102b, 102c may communicate with gNBs
180a, 180b, 180c without also accessing other RANs (e.g., such as
eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs
102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c
as a mobility anchor point. In the standalone configuration, WTRUs
102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using
signals in an unlicensed band. In a non-standalone configuration
WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a,
180b, 180c while also communicating with/connecting to another RAN
such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b,
102c may implement DC principles to communicate with one or more
gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c
substantially simultaneously. In the non-standalone configuration,
eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs
102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional
coverage and/or throughput for servicing WTRUs 102a, 102b,
102c.
[0079] Each of the gNBs 180a, 180b, 180c may be associated with a
particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the UL and/or DL, support of network slicing, dual
connectivity, interworking between NR and E-UTRA, routing of user
plane data towards User Plane Function (UPF) 184a, 184b, routing of
control plane information towards Access and Mobility Management
Function (AMF) 182a, 182b and the like. As shown in FIG. 1D, the
gNBs 180a, 180b, 180c may communicate with one another over an Xn
interface.
[0080] The CN 115 shown in FIG. 1D may include at least one AMF
182a, 182b, at least one UPF 184a,184b, at least one Session
Management Function (SMF) 183a, 183b, and possibly a Data Network
(DN) 185a, 185b. While each of the foregoing elements are depicted
as part of the CN 115, it will be appreciated that any of these
elements may be owned and/or operated by an entity other than the
CN operator.
[0081] The AMF 182a, 182b may be connected to one or more of the
gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may
serve as a control node. For example, the AMF 182a, 182b may be
responsible for authenticating users of the WTRUs 102a, 102b, 102c,
support for network slicing (e.g., handling of different PDU
sessions with different requirements), selecting a particular SMF
183a, 183b, management of the registration area, termination of NAS
signaling, mobility management, and the like. Network slicing may
be used by the AMF 182a, 182b in order to customize CN support for
WTRUs 102a, 102b, 102c based on the types of services being
utilized WTRUs 102a, 102b, 102c. For example, different network
slices may be established for different use cases such as services
relying on ultra-reliable low latency (URLLC) access, services
relying on enhanced massive mobile broadband (eMBB) access,
services for machine type communication (MTC) access, and/or the
like. The AMF 162 may provide a control plane function for
switching between the RAN 113 and other RANs (not shown) that
employ other radio technologies, such as LTE, LTE-A, LTE-A Pro,
and/or non-3GPP access technologies such as WiFi.
[0082] The SMF 183a, 183b may be connected to an AMF 182a, 182b in
the CN 115 via an N11 interface. The SMF 183a, 183b may also be
connected to a UPF 184a, 184b in the CN 115 via an N4 interface.
The SMF 183a, 183b may select and control the UPF 184a, 184b and
configure the routing of traffic through the UPF 184a, 184b. The
SMF 183a, 183b may perform other functions, such as managing and
allocating UE IP address, managing PDU sessions, controlling policy
enforcement and QoS, providing downlink data notifications, and the
like. A PDU session type may be IP-based, non-IP based,
Ethernet-based, and the like.
[0083] The UPF 184a, 184b may be connected to one or more of the
gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may
provide the WTRUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF
184, 184b may perform other functions, such as routing and
forwarding packets, enforcing user plane policies, supporting
multi-homed PDU sessions, handling user plane QoS, buffering
downlink packets, providing mobility anchoring, and the like.
[0084] The CN 115 may facilitate communications with other
networks. For example, the CN 115 may include, or may communicate
with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server)
that serves as an interface between the CN 115 and the PSTN 108. In
addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with
access to the other networks 112, which may include other wired
and/or wireless networks that are owned and/or operated by other
service providers. In one embodiment, the WTRUs 102a, 102b, 102c
may be connected to a local Data Network (DN) 185a, 185b through
the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and
an N6 interface between the UPF 184a, 184b and the DN 185a,
185b.
[0085] In view of FIGS. 1A-1D, and the corresponding description of
FIGS. 1A-1D, one or more, or all, of the functions described herein
with regard to one or more of: WTRU 102a-d, Base Station 114a-b,
eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b,
UPF 184a-b, SMF 183a-b, DN 185a-b, and/or any other device(s)
described herein, may be performed by one or more emulation devices
(not shown). The emulation devices may be one or more devices
configured to emulate one or more, or all, of the functions
described herein. For example, the emulation devices may be used to
test other devices and/or to simulate network and/or WTRU
functions.
[0086] The emulation devices may be designed to implement one or
more tests of other devices in a lab environment and/or in an
operator network environment. For example, the one or more
emulation devices may perform the one or more, or all, functions
while being fully or partially implemented and/or deployed as part
of a wired and/or wireless communication network in order to test
other devices within the communication network. The one or more
emulation devices may perform the one or more, or all, functions
while being temporarily implemented/deployed as part of a wired
and/or wireless communication network. The emulation device may be
directly coupled to another device for purposes of testing and/or
may performing testing using over-the-air wireless
communications.
[0087] The one or more emulation devices may perform the one or
more, including all, functions while not being implemented/deployed
as part of a wired and/or wireless communication network. For
example, the emulation devices may be utilized in a testing
scenario in a testing laboratory and/or a non-deployed (e.g.,
testing) wired and/or wireless communication network in order to
implement testing of one or more components. The one or more
emulation devices may be test equipment. Direct RF coupling and/or
wireless communications via RF circuitry (e.g., which may include
one or more antennas) may be used by the emulation devices to
transmit and/or receive data.
[0088] Embodiments disclosed herein may relate to gyroscope scale
calibration techniques, for example using magnetometer measurements
in a robotic vacuum cleaner and/or using other scale calibrations
including on-device and/or manual scale calibrations, among others.
The techniques disclosed herein may be used in other types of
devices, for example WTRUs and/or IMUs and/or moving devices, in
which one or more gyroscopes may be implemented. In some
representative embodiments, the devices may include one or more
gyroscopes that may be associated with a magnetometer.
Representative Procedures Using a Magnetometer to Dynamically
Calibrate a Gyroscope Scale
[0089] Robotic vacuum cleaners (RVCs) have become more and more
popular as well as diverse. The "robotic" aspect generally means
that the vacuum cleaner sweeps the floor without a human operator.
The first produced RVCs moved more or less according to a Brownian
movement, changing direction when encountering an obstacle. These
first RVCs were quickly replaced by RVCs including more
sophisticated navigation and sensors systems.
[0090] Various types of sensors can be used in RVCs. For example, a
gyroscope is a type of sensor often used in navigation to maintain
direction or control a directional change. A well-calibrated
gyroscope can provide data as to rate of angular change in one or
more planes. Accelerometers are used to sense linear accelerations,
and/or to provide gravity direction as a reference direction.
Magnetometers measure the direction of a magnetic field, which may
be the Earth's magnetic field absent other magnetic field sources,
which data can be used to determine bearing or direction in one or
more planes. A combination of such sensors provides input and
feedback to navigation systems of RVCs and other apparatus.
[0091] Cameras also may be employed to provide visual clues
regarding the environment in which an RVC operates. However, even
with a camera system with a 360.degree. field of vision, it is
difficult to achieve adequate reliability and accuracy in terms of
determining rotation and translation.
[0092] At least two factors play a significant role in the
reliability and accuracy of gyroscopes in terms of the ability to
accurately correlate the gyroscope's readings with angular changes.
A first parameter is bias or zero rate offset (ZRO), which is a
non-zero reading that occurs even if the gyroscope does not
rotate.
[0093] The second parameter is the gyroscope's scale or gain, which
is a factor by which the gyroscope's reading should be multiplied
to convert the gyroscope reading into an angular rate (the angle
characterizing the horizontal plane direction change resulting from
integrating the angular rate change during the rotation). In other
words, gyroscope gain (scaling) is the ratio between the true
angular velocity and the measured value. It is often calibrated in
the factory on a gimbal or turntable. Gyroscope gain can differ
between individual sensors and can change due to conditions like
aging and/or temperature.
[0094] Dynamic calibration of a gyroscope's gain factor can both
save the cost of factory calibration and adapt to changes in gain
due to conditions like aging and/or temperature. Although,
dynamically calibrating the gain of a gyroscope may be difficult
and/or complex, dynamic, post-manufacturing calibration procedures
may be implement, for example, to maintain the accuracy of the
gyroscope readings over time and changing conditions (e.g., as a
correlation to angular change)
[0095] FIG. 2 is a diagram illustrating a representative hardware
architecture for a robotic appliance/apparatus (RAA) 200 that may
be used in various calibration procedures (e.g., for performing a
gyroscope calibration using a magnetometer, for on-board
calibration procedures and/or for calibration procedures using a
predetermined rotation (e.g., a number of 360.degree. rotations),
for example of the RAA 200 using a docketing/charging station,
among others). FIG. 3 is a block diagram illustrating the
representative RAA 200 (e.g., a robotic vacuum cleaner RVC) of FIG.
2 and a representative charging/docketing station 300, in which
representative embodiments may be implemented.
[0096] Referring to FIG. 2, the RAA 200 (for example a robotic
vacuum cleaner RVC, a mobile robot and/or an autonomous vehicle,
among others) may include an IMU 210, one or more motors 270, one
or more batteries 280 (e.g., rechargeable batteries) and/or one or
more other components 290, for example, to enable a robotic task
(e.g., a dust bin and/or a vacuum attachment for a robotic vacuum
cleaner and/or a robotic arm for a mobile robot, among others). The
IMU 210 may include a control unit 215 and/or a sensor package
235.
[0097] The control unit 215 may include a processor 220 (e.g., a
CPU) and/or a memory 230. The processor 220 may receive information
from the sensor package 235. The sensor package 235 may include one
or more gyroscopes 240, one or more magnetometers 250, one or more
accelerometers 260 and other sensors (not shown).
[0098] For example, the processor 220 may receive sample data from
the gyroscopes 240, one or more magnetometers 250 and/or the
accelerometers 260. The processor 220 may execute instructions from
the memory 230 to initiate/execute operations of the RAA including
for example a gyroscope calibration procedure, as described herein.
The processor 220 may interact with, and/or control, other
elements/components of the RAA 200, e.g., the motor 270 to steer
the RAA 200, the battery 280, and/or the other components 290 of
the RAA 200 such as dust suction components.
[0099] Referring now to FIG. 3, the RAA 200 may include a housing
205 with a circular or semi-circular profile in a horizontal plane,
and with a height of approximately 2-10 inches. The housing 210 may
provide a support structure for a motor 270, a battery 280, a dust
bin 290, and/or an IMU 210. The IMU 210 may include a sensor
package 235 and/or a control unit 215. The control unit 215 may
include a processor 220 and a memory 230. In certain representative
embodiments, the sensor package 235 and/or the control unit 215 may
be any number of components or may be partially or entirely
integrated. In certain representative embodiments, the sensors
package 235 may include, for example, a gyroscope 240, a
magnetometer 250, an accelerometer 260, and/or other sensors.
[0100] When the RAA 200 is not in use, the RAA 200 may be docked at
a docking/charging station 300 by the processor 220 of the RAA 200
navigating the RAA 200 to a position for a docking connector 295 of
the RAA 200 to couple with (e.g., electrically or magnetically
couple with) a docking connector 310 of the docking/charging
station 300. For example, the RAA 200 may mate with the
docking/charging station 300 for the battery 280 to recharge (e.g.,
either via a wired connection or wirelessly). The docking/charging
station 300 and the RAA 200 may be shaped to properly align the RAA
200 with the docking/charging station 300, for example to ensure
proper mating and/or to ensure a reliable and repeatable
positioning (e.g., rotational positioning) of the RAA 200 (below a
threshold rotational amount) sufficient for gyroscope scale
calibration.
[0101] Although a single motor is shown in FIG. 2, the RAA 200 may
include separate motors, for example in a RVC for suction, and/or
for moving the RVC, among others.
[0102] The sensor package 235 may include at least a group of
inertial sensors (for example any of: a gyroscope 240, a
magnetometer 250, and/or an accelerometer 260, among others). Each
sensor 240, 250 and/or 260 may provide up to 3 axes of detection.
The sensor package 235 may include one or more cameras and/or other
sensors. For example, the sensor package 235 may include one or
more proximity sensors, one or more bump/contact sensors that may
provide information enabling, for example, any of: (1) tilt
detection, (2) bump/contact detection, and/or (3) location
detection, among others and/or sensors that detect an operational
state of the RAA 200 (for example, in certain representative
embodiments, wheel slippage, operating temperature and/or bin
fullness, among others).
[0103] The control unit 215 may include one or more processors
and/or dedicated circuits to control the RAA 200 and to interface
with a user. The control unit 215 may include hardware and/or
software that form a navigation system configured to (e.g., able
to) perform simultaneous localization and mapping (SLM). The
mapping may be used to plan a trajectory of the RAA 200 (e.g., to
plan an efficient trajectory, for movement/operation of the RAA
200). In some representative embodiments, the RAA 200 may be used
as a RVC and the control unit 215 may include dedicated hardware
and/or software for automatic bin emptying, and/or remote control
for spot cleaning, among others.
[0104] The navigation system may use readings of the gyroscope 240
to track the heading of the RAA 200 (e.g., to track a motion
direction), and/or may use information related to the accelerometer
250 and/or traction system (e.g., wheel rotation information) to
track translation of the RAA 200. According to certain embodiments,
the scale of the gyroscope 240 may be calibrated using information
from the magnetometer 250.
[0105] Those skilled in the art appreciate that the disclosed
embodiments of the RAA include but are not restricted to a RVC.
[0106] FIGS. 4A and 4B are a set of graphs illustrating a
representative calibration procedure in a first environment. FIGS.
5A and 5B are another set of graphs illustrating the calibration
procedure of FIGS. 3A and 3B in a second environment (e.g., a more
disruptive magnetic field environment). FIGS. 6A and 6B are another
set of graphs illustrating the calibration procedure of FIGS. 3A
and 3B in a third environment (e.g., an even more disruptive
magnetic field environment).
[0107] Referring now to FIGS. 4A, 5A and 6A, the RAA 200 may
perform and/or may be controlled to perform a plurality of
360.degree. rotations about a vertical axis (the z axis)
(hereinafter designated as N+1 rotations). As the RAA 200 rotates,
for each such 360.degree. rotation, the magnetometer 250 may
measure the magnetic field at a plurality of reference points
(e.g., reference points 1-12 in FIGS. 4A, 5A and 6A (the number of
reference point hereinafter designated as M reference points).
Merely as an example, the reference points may be designated at
M=12 evenly spaced angular positions (e.g., bearings, for example
every 30.degree.). The reference points may be evenly spaced or the
intervals between reference points may vary (e.g., within a
rotation) and the number of reference points may be more or less
than 12. The data collected from the magnetometer 250 may be used
to calibrate the scale of the gyroscope 240 as described in detail
herein. The RAA 200, for example, may be programmed to perform a
number of rotations after (e.g., immediately after) the RAA 200 has
left the docking/charging station 300. In addition to or in lieu of
rotations immediately after the RAA 200 has left the
docking/charging station 300, rotations may be performed as part of
the normal movement of the RAA 200 (vacuuming motions of an RVC,
for example). The magnetometer 250 may be calibrated or
uncalibrated prior to performing the rotations from which data is
collected to determine the scale of the gyroscope 240.
[0108] If the magnetometer 250 is calibrated (e.g., perfectly
calibrated) and the magnetic measurements (e.g., all of the
magnetic measurements) are taken in an ideal, unchanging magnetic
field, at all points in a rotation, the magnetometer 250 will
measure the same magnitude and a different orientation for the
magnetic field (e.g., as projected onto the horizontal plane)
forming a circle (e.g., an approximate circle) as illustrated in
FIG. 4A. In more realistic conditions, the measurements may look
rather like that shown in FIG. 5A. By way of comparison, if
conditions are poor (e.g., significant changes in the surrounding
magnetic field), the magnetometer readings may realistically be as
shown in FIG. 6A. For example, the conditions can become worse
because of magnetic field fluctuations/changes due to, for example,
electromagnetic activity in the area such as current carrying
conductors and/or large metallic (e.g., ferromagnetic materials)
near or adjacent to the RAA 200.
[0109] In certain representative embodiments, at least the first
rotation of the N+1 rotations of the RAA 200 may be used to find
the M reference points for magnetic fields (e.g., for measurement
of the magnetic fields). The subsequent N turns may be used to
collect data to be used to determine (calibrate) the scale (i.e.,
scale factor or scale correction) of the gyroscope 240. For
example, after the RAA 200 is determined to be or detected to be
rotating at a constant rate, gyroscope integration may be started
to provide heading angles. Even though the scale of the gyroscope
is not determined yet, whether the rotation rate is constant may
(e.g., may still) be determined accurately. Data for M (e.g., M=12)
reference points 1-12 may be recorded. The data may include a
2-tuple (e.g., a 2-tuple for each reference point) including a
heading angle (as determined from the gyroscope integration data)
and a 3D magnetic field vector (as determined from the magnetometer
output data). Each reference point may be assigned an index, e.g.,
reference point index 1 through 12.
[0110] For the next N rotations, the gyroscope scale may be
calibrated based on the data collected. For example, on condition
that the output of the magnetometer 250 matches (e.g., for example,
one time, multiple times or every time the output of the
magnetometer 250 matches) the magnetometer vector of one of the
reference points (indicating, in theory, that the RAA 200 is at the
same heading (i.e., angular orientation) as the corresponding
reference point 1-12), the 2-tuple recorded at that point may be
used to update the gyroscope scale estimate.
[0111] There are many ways to determine when the RAA 200 has
reached the point closest to the same heading as one of the
reference points 1-12. In certain representative embodiments, to
determine when the RAA 200 has reached a closest heading to a given
reference point 1-12, the 2-tuples may be sampled from the output
of the magnetometer 250 and the output of the gyroscope 240 at a
relatively high rate, e.g., in a range of several hundred to a
thousand times per 360.degree. rotation. When a sampled reading of
the output of the magnetometer 250 is within a particular threshold
of one of the reference points 1-12, the 2-tuple may be used to
calculate the gyroscope scale. As the RAA 200 continues to rotate,
if a sampled reading of the magnetometer 250 is recorded that is
closer to that reference point 1-12, the gyroscope scale may be
updated (e.g., updated again) using that latest 2-tuple data.
[0112] In certain representative embodiments, instead of using
(e.g., immediately using) a 2-tuple (e.g., every 2-tuple) that is
less than the threshold to update the gyroscope scale, the 2-tuples
(e.g., all of the 2-tuples) within the threshold may be saved
(e.g., temporarily saved) until the RAA 200 determines the 2-tuple
for which the sampled reading of the magnetometer 250 is closest to
the reference point 1-12 (e.g., and may use (e.g., may only use)
that one sampled reading to update the gyroscope scale). Because
the calculation of the gyroscope scale may be a relatively low cost
calculation, and saving those 2-tuples may require or may use
memory 230, overall, the gyroscope's scale may be calculated for
2-tuples (e.g., each 2-tuple) that are within the threshold, for
example, in lieu of saving multiple 2-tuples within the threshold
and determining which one has the closest sampled reading of the
magnetometer 250.
[0113] In certain representative embodiments, the RAA 200 may use a
set of the closest sampled readings to interpolate to estimate the
reading of the magnetometer 250 at the particular reference point
1-12. The interpolation may use a linear or a non-linear
interpolation operation.
[0114] As previously mentioned, the reference points 1-12 may be
assigned indices and the processing algorithm may keep track of the
index of the reference point 1-12 that is being considered at that
moment (e.g., at each moment). The operation may start with a
setting of a counter to an index of the first reference point,
e.g., 1, after (e.g., immediately after) a last of the M reference
points has been established during the initial rotation. The
counter may remain at a current index value (e.g., 1) until the
sampled reading of the magnetometer 250 of the currently sampled 2
tuple becomes closer to the magnetometer reading corresponding to
the next reference point (e.g., reference point 2) than to the
current reference point (e.g., reference point 1). At that point,
the index (e.g., index=1) may be updated to the next value (e.g.,
index=2).
[0115] Some or all of the M reference points (e.g., reference
points 1-12) may be used as references to calculate the M gyroscope
scale estimates, respectively. After the N+1 rotations are
completed, the M gyroscope scale estimates (e.g., one for each of
the M reference points (e.g., reference points 1-12), with each of
those M estimates being based on N 2-tuples) may be averaged to
obtain a single gyroscope scale estimate.
[0116] In certain representative embodiments, if a repeatability of
the magnetometer 250 is AO degree, a gain accuracy of the gyroscope
240 may be as set forth in Equation 1, as follows:
.DELTA..theta. .pi. / 180 2 .times. .pi. .times. N = ( .DELTA.
.times. .theta. 3.6 .times. N ) .times. .times. % ( 1 )
##EQU00001##
[0117] where: N is the number of rotations, and AO is the
magnetometer repeatability factor. As reflected in Equation 1,
gyroscope gain estimate accuracy may improve with both an increase
in the number of rotations N, and a decrease in the magnetometer
repeatability/accuracy factor .DELTA..THETA. (for example a
decrease in the magnetometer repeatability/accuracy factor
.DELTA..theta. may correlate to an improvement in
repeatability/accuracy of the magnetometer readings).
[0118] Table 1 below illustrates the gain accuracy of a gyroscope
240 as a function of the number of rotations and magnetic field
repeatability according to Equation 1. The magnetometer
repeatability may depend on (e.g., more on) the magnetic
environment than on measurement noise, as low pass filtering may
significantly remove the noise. Experiments have shown that a
magnetometer repeatability factor .DELTA..theta., of about
1.5.degree. is near the top end of what may be practically
achievable in the real world, that about 2.8.degree. may be more
typical, but that a bad real world magnetic field may be as bad as
17.degree. or worse.
[0119] The gyroscope gain estimate accuracy may improve with an
increasing number of sample points M. For example, averaging over M
reference points may reduce (e.g., may further reduce) the gain
error by about {square root over (M)}.
[0120] For a typical magnetometer field repeatability of about
2.8.degree., an accuracy of 0.25% or greater in the gyroscope gain
estimate may be achieved most of the time using the techniques
and/or procedures disclosed herein with about 3 to 4
rotations/spins of the RAA 200 (e.g., N=3 to 4) and, for example 12
reference points (e.g., M=12).
[0121] FIGS. 4B, 5B, and 6B illustrate a convergence of gyroscope
scale to the correct value of 0.99 as a function of number of
rotations. An accuracy error of 0.25% may be achieved even if the
magnetometer measurements are not well calibrated, such as in the
third environment of FIG. 6B.
TABLE-US-00001 TABLE 1 N + 1 = N + 1 = N + 1 = N + 1 = N + 1 = 2 3
4 5 6 .DELTA..theta. = 1.degree. 0.28% 0.14% 0.09% 0.07% 0.06%
.DELTA..theta. = 2.degree. 0.56% 0.28% 0.19% 0.14% 0.11%
.DELTA..theta. = 3.degree. 0.83% 0.42% 0.28% 0.21% 0.17%
.DELTA..theta. = 5.degree. 1.39% 0.69% 0.46% 0.35% 0.28%
.DELTA..theta. = 15.degree. 4.17% 2.08% 1.39% 1.04% 0.83%
[0122] The error sources affecting accuracy may include any of: (1)
magnetic field interference, (2) measurement noise, (3) delay
between magnetometer and gyroscope data, (4) rotation not exactly
around the desired axis, (e.g., the z axis using the RAA 200
example), and/or (5) magnetic field changes when rotating, caused,
for instance, by horizontal translation of the RAA 200 on the floor
while rotating, among others.
[0123] Gain calibration accuracy may generally improve with (1) the
number of rotations, and/or (2) the number of reference points per
rotation. FIGS. 4B, 5B and 6B illustrate convergence of the
operation and/or algorithm to a gain calibration accuracy of about
0.99.
[0124] FIG. 7 is a flow diagram illustrating a representative
calibration procedure that may be implemented by the control unit
215 and/or a processor employing software, hardware and/or
combinations thereof. At operation 710, the RAA 200 (e.g., such as
a RVC) may be instructed to begin rotating about an axis (for
example as stationary as possible, and in the case of the RVC, for
example vertical, e.g., not tilted). On condition that and/or once
the rotation is determined to be at a steady rate at operation 712,
at operation 714, the RAA 200 may start to collect 2-tuples of (1)
angular heading (e.g., from the integration of the gyroscope
output) and (2) magnetic vector readings (e.g., from the
magnetometer).
[0125] In certain representative embodiments, a calibration
procedure may be triggered based on a determined location or
vicinity to the docketing/charging station 300. For example, the
calibration procedure may be triggered: (1) after the RAA 200 is
switched on, (2) prior to or just after the RAA 200 leaves the
docketing/charging station 300 and/or (3) just prior to or just
after the RAA 200 returns to the docketing/charging station
300.
[0126] At operation 716, the RAA 200 may assign an index to each
reference point. At operation 718, the RAA 200 may set a rotation
counter to N=1 to start counting rotations after the data for the M
reference points is collected. At operation 720, the RAA 200 may
assign an index, I, to each reference point. At operation 722, the
RAA 200 may start taking and/or sampling reading from the
magnetometer 250 and gyroscope 240 (e.g., as 2-tuples) at a rate
higher than (e.g., substantially higher than) M samples per full
rotation. For example, the rate of sampling may be at least a
threshold more than M. At operation 724, the RAA 200 may determine
if the output of the magnetometer 250 is within a predetermined
threshold of the magnetic vector stored for reference point I. If
so, the flow may proceed to operation 726, and the RAA 200 may
determine if the current reading of the magnetometer 250 is closer
to the magnetic vector of the current reference point than the
previous closest reading of the magnetometer 250 since the
threshold was met (which may be true (e.g., which always be true)
for the first reading of the magnetometer 250 that is within the
threshold). Although not shown explicitly in FIG. 7, the
determination may, be done by storing the closest sample, comparing
the current sample to the previously stored closest sample, and
updating the stored closest sample whenever a closer sample is
received.
[0127] When both the condition at operation 724 and the condition
at operation 726 are met, the flow may proceed to operation 728,
and the 2-tuple of angle and magnetic vector may be used to update
the gyroscope scale factor (sometimes referred to as
ScaleCorrection) for reference point I. If at operation 726 the
current reading of the magnetometer 250 is not determined to be
closer to the magnetic vector corresponding to the current
reference point I than the previous reading, the flow may skip over
operation 728 such that the sample is not used to update the
gyroscope scale estimate.
[0128] Returning to operation 724, if the reading of the
magnetometer 250 is not within the threshold, flow may skip from
operation 724, over operation 726 and 728 and may flow to operation
730 (e.g., directly to operation 730.
[0129] At operation 730, the RAA 200 may determine if the current
reading of the magnetometer 250 is closer to the magnetic vector
corresponding to the next reference point I+1 than to the magnetic
vector corresponding to the current reference point I. If the
current reading of the magnetometer 250 is not closer to the
magnetic vector corresponding to the next reference point I+1 than
to the magnetic vector corresponding to the current reference point
I, the flow may proceed to operation 722, for example to read and
process the next 2-tuple sample to determine if the next 2-tuple
sample is closer than the last 2-tuple sample in accordance with
operations 722 through 728. If the current reading of the
magnetometer 250 is closer to the magnetic vector corresponding to
the next reference point I+1 than to the magnetic vector
corresponding to the current reference point I, the flow may
proceed to operation 732, and the index I may be updated to I+1 to
start working on the next reference point.
[0130] At operation 734, the RAA 200 may determine if the index I
has reached M (indicating that a full 360.degree. rotation has been
completed). If the index I has not reached M, the flow may proceed
to operation 722 to take the next sample (e.g., which may be
compared to the next reference point). If the index I has reached M
(e.g., indicating that a full rotation has been completed), the
flow may proceed to operation 736, and N may be incremented (e.g.,
indicating that a 360.degree. rotation has been completed and the
next 360.degree. rotation has started) and I may be reset to 1 (for
example, to return to collecting data for the first reference
point). At operation 738, the RAA 200 may determine if N (which
indicates the number of rotations completed since the first
rotation (e.g., the reference point gathering rotation) has reached
the predetermined number of complete rotations (e.g., 12
rotations). If the number of rotations completed since the first
rotation has not reached the predetermined number of complete
rotations, the flow may return to operation 722 to take the next
sample. If the number of rotations completed since the first
rotation has reached the predetermined number of complete
rotations, all of the data may have been collected and processing
may proceed to operation 740, and the scales estimated for each of
the M reference points may be averaged and/or weighted to generate
a final gyroscope scale estimate.
[0131] In certain representative embodiments, some or all of the M
scale estimates may be assigned a weight based on the quality of
the data corresponding to that reference point. The quality of the
data may be determined, for instance, based on any of the criteria
mentioned above for use in determining which, if any, samples to
discard. For example, the quality of the data may correspond to the
number of magnetometer samples that are properly matched to a
reference point (e.g., within a threshold of the reference point)
At operation 742, processing may end.
[0132] Additional error sources that may affect the accuracy of the
gyroscope scale estimate include undesired translation of the RAA
200 in a plane perpendicular to the axis of measurement during the
N+1 rotations (e.g., horizontal translation of the RAA 200). For
instance, it has been found that, while current commercially
available RVCs remain reasonably stationary while rotating on a
hard surface (e.g., a hardwood floor), the RVCs may tend to
translate (commonly referred to as "walk") during such rotation
operations when on a softer surface, such as carpet. Such walking
may cause undesired changes to the magnetic field measured by the
magnetometer 250. One potential solution to address this issue is
to design the RVC and the docking station so that the N+1 rotations
can be performed while the RVC is in the docking station.
[0133] In certain representative embodiments, the N rotations after
the first rotation may be split into a first set of rotations in
one direction (e.g., clockwise) and a second set of rotations in
the opposite direction (e.g., counterclockwise). In these
embodiments, the RAA 200 may tend to continue to walk in the same
general direction regardless of a reversal of the rotation
direction. However, if the magnetic field gradient over the course
of the horizontal translation of the RAA 200 is relatively uniform,
the errors in each of the two sets of rotations may tend to cancel
each other out.
[0134] In other representative embodiments, rather than selecting a
particular number of reference points, M, the RAA 200 based on an
algorithm may use every measurement point. For instance, during the
first rotation, every 2-tuple may be stored, and during the N
subsequent rotations, a sampled 2-tuple (e.g., each measurement
2-tuple) may be matched to a reference 2-tuple based on a closest
reading of the magnetometer 250 (e.g., a smallest distance in terms
of a magnetometer XY magnetic field reading, a magnetometer XYZ
magnetic field reading, and/or an angular distance in polar
coordinates, among others). This may increase (e.g., may
significantly increase) processing load and memory requirements.
Empirical observations appear to reveal no appreciable improvement
in accuracy from using all available samples as opposed to, for
example, a small number of reference points, e.g., M=6 to 12
reference points.
[0135] In certain representative embodiments, accuracy may be
improved by not using samples that have certain characteristics
that are indicative of magnetic field change. For instance, if the
matching sample for a given reference point (e.g., the sample taken
during the second to N+1th rotation that is closest as a function
of distance between the magnetometer output corresponding to the
corresponding reference point and magnetometer output for the
sample) has a relatively large matching error as compared to most
other matching samples, that sample may be discarded, rather than
be used to update the scale estimate. In certain representative
embodiments, a threshold based on a number of standard deviations,
for example in the range of about 1 to 3 standard deviations or of
2 standard deviations, may be set to determine whether to use or
discard a matching sample.
[0136] Another possible criterion to discard matching samples may
be to discard all the data in a complete rotation if a center of
the magnetic circle for that rotation as shown in FIGS. 4A, 5A and
6A is offset by an amount greater than a predetermined threshold
from the center of a reference circle. Another criterion to discard
one or more samples of a complete rotation may be based on a shape
traced by the magnetic field readings during the complete rotation
or part of the complete rotation. For instance, if the shape is too
far from a circle, the data for the complete (e.g., the entire)
rotation may be discarded or if a portion of the shape is too far
from that portion of the circle, the data for that portion of the
complete rotation may be discarded.
[0137] A further criterion to discard one or more samples is to
compare the shape of the 2D projection of the magnetic field during
the reference rotation, to the shape of the subsequent rotations.
Any shape similarity metric may be used (for example such that the
similarity metric is greater than or less than a threshold value).
One representative metric may be to compute the non-overlapping
area of the two shapes. A second metric may be to first compute the
non-overlapping area of the two shapes and then normalize the
result by the average area of the two shapes. A further criterion
to discard one or more samples of a complete rotation may be based
on the amplitude of the magnetic vectors. For example, if the
amplitude of the measured magnetic field differs from the amplitude
of the corresponding reference point's magnetic field by greater
than a threshold amount, the sample may be discarded. It is
contemplated that the center of the circle of the magnetic vector
measurements may be offset from zero, if the center of the circle
of the magnetic vector measurements is offset from zero, the
amplitude may be measured from the center of the circle rather than
true zero. In some representative embodiments, in which unreliable
samples may be discarded, the RAA 200 may be controlled to rotate N
times, and only those ones of the N rotations that meet one or more
of the aforementioned criteria may be used in computing the
gyroscope scale factor. In certain representative embodiments, the
RAA 200 may be controlled to continue to rotate until N "good"
rotations (e.g., N rotations that meet the one or more criteria)
have been completed.
[0138] In certain representative embodiments, magnetometer
repeatability (e.g., only magnetometer repeatability) may be used
for calibration of the gyroscope scale factor.
[0139] In certain representative embodiments, magnetometer points
may be used while the RAA 200 is rotating, (e.g., in lieu of or in
addition to stable points in which the measurements are taken after
stopping to rotation of the RAA 200), as the same stable points
(e.g., within a threshold tolerance) for different rotations of the
RAA 200 may or may not be achievable.
[0140] In certain representative embodiments, a filter may be
applied to one or both of samples/reading of the gyroscope 240 and
the samples/readings of the magnetometer 250, for example to reduce
noise. For example, the applied filter may include (1) an Infinite
Impulse Response (IIR) filter and/or (2) a Finite Impulse Response
(FIR) filter, among others, for example to reduce noise.
[0141] In certain representative embodiments, the same filters may
be used to keep the delay associated with the samples/readings of
the gyroscope 240 and the samples/readings of the magnetometer 250
the same.
[0142] Tilt, e.g., which refers to any component of rotation that
is not around the axis about which the rotation is set, intended,
or believed to be occurring, may reduce the accuracy of the
gyroscope scale estimate.
[0143] Continuing with the RAA 200 example, the intended axis of
rotation may be a vertical axis, e.g., the axis of gravity, which,
may be the z-axis of the sensors. The tilt error may be the result
of, for example, two causes. First, the supporting surface (e.g.,
the floor) may be tilted (e.g., the floor may not be perpendicular
to gravity). In the body frame of the sensor package 235 or one or
more of the sensors 240, 250 and/or 260 (e.g., the frame of
reference of the magnetometer 250 and/or the gyroscope 240), the
ideal output of the magnetometer 250 may still be a circle in the
plane perpendicular to their vertical axis, just a different circle
from the case without tilt. Since such embodiments rely (e.g., only
rely) on magnetometer repeatability, there should be no extra error
caused by any magnetometer field change resulting from, for example
floor tilt. Since the rotation axis of the RAA 200 may still be the
same as a z axis of one or more sensors 240, 250 and/or 260
(although it may not be vertical anymore), the gyroscope 240 may
still show rotation in its z axis. These embodiments described
above may be immune to this first type of tilt.
[0144] Second, the sensor package 235 and/or one or more sensors,
e.g., the magnetometer 250 and/or the gyroscope 240) may be mounted
in the RAA 200 at a slight tilt from the presumed vertical axis of
the RAA 200 (commonly referred to as circuit board tilt or just
board tilt). The axis of rotation may be the vertical axis of the
RAA 200 (e.g., corresponding to the z axis). Measured in the body
frame of the gyroscope 240, the angular velocity may not be along
the vertical axis of the sensors 240, 250 and/or 260 anymore due to
the tilt. If the vertical axis of the gyroscope 240 is the u
direction, it is contemplated that the u direction may be the
vertical axis of the magnetometer 250 also, for a magnetometer 250
that is accurately mounted on the same board as the gyroscope 240.
The rotation that the sensors (e.g., the magnetometer 250 and/or
the gyroscope 240) experience may not solely be about their
vertical axes, but also may be about their x and/or y axes. Regular
gyroscope integration along the sensors' z axis may lose the
rotation energy in the x and y axes, and may result in an error in
the heading change calculated via gyroscope integration.
[0145] One way to compensate for any difference between z and u may
be to measure the tilt, adjust the readings from the sensors to
undo and/or compensate for the tilt (e.g., by removing the effect
of the tilt via eliminate any component of rotation around the x
and y axes from the measured values), and perform the updating of
the gyroscope scale using the adjusted readings. In certain
representative embodiments, if the sensor package 235 or a sensor
board includes an accelerometer 260 and dynamically determines a
zero-gravity offset (ZGO) of the accelerometer 260, tilt may be
based on and/or obtained from the dynamic ZGO calibration.
[0146] In certain representative embodiments, a first order
approximation of gyroscope integration may be obtained by taking
the norm of the angular velocity measured by the gyroscope 240 in
the direction u as the angular velocity in z.
[0147] Any delay between the taking of the reading of the
magnetometer 250 and the taking of the reading of the gyroscope 240
may degrade the accuracy of the scale estimate (due to the reading
of the magnetometer 250 being taken at a different angle of
orientation than the reading of the gyroscope 240 because of the
delay). One way to address this potential source of error is to
stop the RAA 200 at a portion of the reference points, or each
reference point before taking the 2-tuple measurements. This may
guarantee for those reference point where the RAA 200 is stopped
such that the two measurements are taken with the RAA 200 at the
same angular orientation. It may not be feasible to stop at the
exact same angle as the reference points, since the gain of the
gyroscope 240 is not accurate (and that is why the gyroscope 240 is
being dynamically calibrated). The changing currents and
electromagnetic fields resulting from starting and stopping the
motor that rotates the RAA 200 may cause (e.g., actually cause)
more interference and/or noise in the readings from the
magnetometer 250. The representative procedures described above of
taking measurements frequently and determining which 2 tuples of
measurements is the one closest to a reference point may provide an
accurate matching (e.g., very accurate matching, for example within
a threshold level) of angular orientation of the measurement
samples to the reference points.
[0148] Although the representative embodiments associated with at
least FIGS. 2-3, 4A, 4B, 5A, 5B, 6A, 6B and 7 are illustrated using
a RAA, it is contemplated that any other device (e.g., robotic
and/or non-robotic) which includes a gyroscope and a magnetometer
may implement these embodiments. For example, an Inertial
Measurement unit (IMU), a Timing & IMUs (TIMU), a mobile
device, a head mounted display, a WTRU and/or smartphones, among
others may implement such embodiments.
Representative Gyroscope Scale Calibration Procedures Based on
Angular Position of a Device
[0149] For proper performance of an IMU, a Timing & IMUs
(TIMU), and other devices that include a gyroscope including, for
example, a mobile device, a head mounted display, a WTRU and/or
smartphones, among others, it may be appropriate to have a
calibrated device. For a device that moves predominantly in a plane
(e.g., a single plane such as a robot that may move around the
floor), the gyroscope associated with the device may have a
plurality of parameters (e.g., two key parameters) that may need to
be or are to be calibrated. One parameter to be calibrated may be
the Z-axis (i.e., parallel to gravity) zero-rate offset (ZRO), and
the other parameter to be calibrated may be the Z-axis scale (also
referred to as the `gain` and/or the `sensitivity`).
[0150] A linear 1-axis calibration equation is set forth in
Equation 2 as follows:
G calib = S * ( G uncal + O ) ( 2 ) ##EQU00002##
where: G.sub.calib is the calibrated gyroscope output; S is the
gyroscope scale; G.sub.uncal is the uncalibrated gyroscope input;
and O is the gyroscope zero-rate offset (ZRO).
[0151] In certain representative embodiments, methods, procedures,
apparatus, and/or devices may be implemented to dynamically
calibrate a ZRO.
[0152] In other representative embodiments, methods, procedures,
apparatus, and/or devices may be implemented to calibrate a
gyroscope scale, for example without additional information and/or
constraints. A gyroscope scale may be calibrated in a factory
setting by rotating the gyroscope on a turntable that may move at a
pre-determined or measured rate of speed. The calibration procedure
may include any of the following:
[0153] (1) calibrate ZRO by having the device stationary, and
measure the uncalibrated gyroscope value at rest, G.sub.rest, and
compute O=-G.sub.rest;
[0154] (2) spin/move the gyroscope at a constant rate
G.sub.truth;
[0155] (3) measure the uncalibrated gyroscope value when in motion,
G.sub.motion; and/or
[0156] (4) compute the scale: S=G.sub.truth/(G.sub.motion+O).
[0157] The calibration may be done (e.g., completed) using or with
a single measurement, by averaging multiple measurements, or by
using multiple measurements and finding the scale that gives the
smallest residual difference between G.sub.truth and
G.sub.calib.
[0158] A 1-axis gyroscope scale may be calibrated by gyroscope
integration. A turntable may have inaccuracies associated with its
angular velocity (e.g., rotational speed). For example, (1) the
turntable may not be able to rotate at precisely a known speed, (2)
may not have encoders or other means to measure the angular
velocity of the turntable, and/or (3) may not have encoders or
other means to measure the angular velocity of the turntable
precisely, among others. If the turntable can stop at a known
angular position (e.g., at a precisely known angular position, for
example within a positional threshold), the gyroscope may be
calibrated using the turntable, test fixture or other device that
can set a known angular position (e.g., an angular displacement
from an initial angular position). In this case, the gyroscope
integration may be compared with the truth motion. The calibration
procedure may include any of the following: [0159] (1) calibrate
ZRO by having the device stationary; [0160] (2) measure the
uncalibrated gyroscope value at rest, G.sub.rest, and compute
O=-G.sub.rest; [0161] (3) initialize the gyroscope integration
position P.sub.int=0; [0162] (4) rotate/move the device a precise
amount P.sub.truth; [0163] (5) while the device is in motion,
integrate all the gyroscope samples:
[0163] P.sub.int=.SIGMA.(G.sub.uncal+O)*.DELTA.T; and/or [0164] (6)
when the device is at rest, compute the scale:
[0164] P truth = .SIGMA. .function. [ S * ( G uncal + O ) ] *
.DELTA. .times. .times. T = S .times. .times. .SIGMA. .function. (
G uncal + O ) * .DELTA. .times. .times. T = S * P int , .times.
.times. and / or ( i ) .times. S = P truth / P int ( ii )
##EQU00003##
Representative Alternative for Rotational Integration Calibration
Procedures
[0165] Since the motion of the gyroscope is around a constant axis,
a linear integration of the gyroscope vector may be equivalent to
rotational integration.
[0166] One example of the rotational integration may be Euler
integration with small-angle approximation. For each angular
velocity reading, any of the following may be executed: [0167] (1)
create/generate quaternion .DELTA.q with the real term as 1, and
the imaginary terms=.omega.*.DELTA.T/2; and/or [0168] (2) update
the current angular position quaternion q=qmult(q, .DELTA.q) where
qmult is quaternion multiplication. where q is the current angular
position and represented as a quaternion; .omega. is the nominally
calibrated gyroscope reading: .omega.=S.sub.nom*(G.sub.uncal+O);
S.sub.nom is the nominal scale, and .DELTA.T is the sampling
period.
[0169] One procedure that may use the rotational integration result
may include to: [0170] (1) convert both quaternions to Euler
angles, and use the Yaw components of each, where; [0171] (2)
compute the scale correction E=P.sub.truth/(Y1-Y0); and/or [0172]
(3) compute the new scale calibration: S=S.sub.nom*E, where q0 be
the initial angular position before the integration, and q1 be the
final angular position after the integration; Y0 is the yaw of q0,
and Y1 is the yaw of q1.
[0173] It is contemplated that the linear integration may handle
rotations larger than 360.degree. and for rotations of less than
360.degree., it is possible to use rotational integration.
Representative Calibration Accuracy
[0174] The accuracy of the gyroscope scale after turntable
calibration may depend on the accuracy of the angle of the
turntable's rotation during the calibration process. The gyroscope
scale correction is set forth in Equation 3 as follows:
ScaleCorrection = MeasuredRotation / ActualRotation ( 3 )
##EQU00004##
[0175] If there are errors in the ActualRotation, the errors may
lead to a proportional error in the calibrated ScaleCorrection. For
example, if the attempted rotation is 180.degree., and there is a
.+-.0.45.degree. variation in the turntable position, the resulting
calibration may be no better than 0.25% of the true calibration. If
the turntable has a fixed amount of error, the scale error may be
reduced, for example by increasing the amount of actual rotation.
For example, the same .+-.0.45.degree. variation with a 360.degree.
rotation may give 0.125% scale error.
Representative On-Board Calibration Procedure
[0176] In a factory calibration configuration, it is contemplated
to send raw data from the device (e.g., being calibration tested)
to a calibration station that can control the turntable. The
calibration station may start logging the data (e.g., the raw
data), move the turntable, finish logging the data, compute the
calibration, save the calibration, and/or send the calibration
(e.g., a calibration record) to the device (e.g., being calibration
tested). The connectivity to enable the logging of the sensor data
and writing of the calibration data back to the device may be a
burden to the implementation of the device, and may lead to a more
complicated test/calibration station. In certain representative
embodiments, the calibration may be executed (e.g., run) directly
on the device (e.g., being calibration tested) or may be executed
partially on the device (e.g., being calibration tested) and
partially external to the device.
[0177] FIG. 8 is a diagram illustrating a representative
calibration procedure.
[0178] To implement a calibration internal to a device (e.g., such
as a WTRU 102, a RAA 200, a IMU 210, or the like, hereafter
sometimes referred to as device 910) without an external
test/calibration station, the device 102, 200 and/or 210 may use a
single input pin that may be connected to a switch (e.g., a
push-button switch) to indicate the start and stop of the
calibration, and two output LEDs, for example red and green LEDs,
which may be used to indicate when the device 102, 200 and/or 210
may be moved (e.g., when it is appropriate to move the device 102,
200 and/or 210), and to indicate if the calibration was successful
or unsuccessful.
[0179] Referring to FIG. 8, the representative calibration
procedure 800 may include any of the following: [0180] (1) place
the device on the turntable and set the device to the starting
position; [0181] (2) at operation 810, press the calibration push
button to indicate a start of the calibration; [0182] (3) at
operations 812 and 814, wait for the Green LED to light, to
indicate that the device/system is ready for rotation; [0183] (4)
at operation 816, rotate/move the turntable 180.degree., and then
leave the device at rest; [0184] (5) at operation 818, press the
calibration button to indicate the end of calibration; and/or
[0185] (6) at operation 820, wait for either the Green LED to
indicate a success calibration, or the Red LED to indicate
calibration failure.
[0186] Although the calibration procedure is disclosed to use a
push-button switch, other types of switch are possible. For
example, a toggle switch may be used and/or a switch that is
activated by the positioning of a device 102, 200 and/or 210 under
test (or for example device 910 in FIG. 9) adjacent to (e.g., in
contact with) the calibration device (e.g., bar 920 in FIG. 9). It
is also possible to avoid the need and/or use for the switch by
detecting that the device is stationary by detecting a stable
period in the gyroscope (e.g., gyroscope 240) and/or the
accelerometer (e.g., accelerometer 260).
[0187] Although the calibration procedure is disclosed to use LEDs
for a visual indication, other types of indications are possible.
For example, an audio indication, a communication to another device
a haptic indication may be used and/or a display or other
presentation device may be used in lieu of or in addition to any
other indication.
[0188] Although the calibration procedure is disclosed to use a
180.degree. rotation, other rotation amounts are possible, as long
as the rotation amount is known (e.g., preconfigured in the device
under test).
Representative Procedures for Information Flow
[0189] A conventional calibration system has the following sources
of data that are collected external to the device being calibrated
in one external point to compute the calibration: (1) the `truth`
motion that describe the motion made by the device (e.g., via
encoders on the turntable); and (2) the `measured` motion from the
device. After computing the calibration, the calibration result is
to be written to the device. The results of the calibration may be
logged for tracking of device performance. Any errors during the
calibration may be logged and may be presented to the operator.
[0190] Using gyroscope integration calibration procedures according
to certain representative embodiments described herein, the truth
motion may be reduced from determining (e.g., knowing) the position
of the turntable at every moment of time throughout the motion to
determining (e.g., only knowing) the change in angle between a
starting point and an ending point. If this amount is fixed, the
truth may be computed, and does not need to be transmitted. If the
calibration is performed on the device, it may not be appropriate
and/or necessary to send sensor data out of the device and/or to
write the calibration record back to the device. Even when the
calibration is done in the device, it may be useful to be able to
query the computed calibration record from the device, and/or be
able to know which errors occurred in the previous calibration.
Representative Calibration Procedures with Support (e.g.,
Automatic) for Different Rotation Amounts
[0191] On-board calibration may support different amounts of
rotations, for example, without needing or using additional (e.g.,
any additional) inputs. For example, the calibration procedure may
round a measured rotation to a nearest Q degrees, where Q is a
large angle (e.g., 45.degree., 90.degree. and/or 180.degree., among
others) and use the measured rotation, as the true rotation. It is
contemplated that when uncalibrated, the device may follow the
Constraint 3 that:
ScaleError * Q * TotalRotations < Q / 2 ( 4 ) ##EQU00005##
in which a bounded error (i.e., ScaleError*Q*TotalRotations) may be
less than Q/2. Here ScaleError is the percentage error, and
TotalRotations is the number of Q degree rotations being measured.
For example, if Q=45.degree. and TotalRotations=5, then the
uncalibrated scale error may be or may need to be less than
10%.
Representative Bar Calibration Procedures
[0192] Creating a turntable that can accurately, precisely, and
repeatability stop at exactly 180.degree. may be possible and may
include some engineering challenges.
[0193] FIG. 9 is a diagram illustrating another calibration
procedure for a device 910 (e.g., a device to be calibrated such as
a IMU, WTRU, robotic device, and/or robotic vacuum, among others)
using a bar 920. FIG. 10 is a diagram illustrating the calibration
procedure for the device 910 rotated 180.degree. relative to a
starting angular position using an opposite side of a bar 920.
[0194] Referring to FIGS. 9 and 10, the calibration procedure may
provide a precise 180.degree. rotation. The device 910 may include:
(1) a flat bottom (and/or points on the bottom that make contact
with another surface (e.g., a support surface) (not shown) to
ensure that the device is not tilted); and (2) at least one flat
side 930 that make contact with (and/or is adjacent to) a side
surface 940 of the bar 920, for example such that the side surface
930 of the device 910 and the side surface 940 of the bar 920 may
form a consistent contact surface. The consistent contact surface,
for example can ensure precisely known and repeatable angular
positions (e.g., within a threshold tolerance for an angular
position of 0.degree. as the starting position and an angular
position of 180.degree. that is relative to the starting position)
for the device 910.
[0195] The bar 920 may be placed on the flat support surface (e.g.,
flat table) (not shown). The bar 920 may have two sides (e.g.,
contact surfaces) that may form two parallel surfaces and that may
match to and/or mate with the flat surface of the device to ensure
that the device 910 is not tilted and is able to be positioned at
precisely known angular positions (at any of: an angular position
of 0.degree. as the starting position or an angular position of
180.degree. that is relative to the starting position).
[0196] A first calibration measurement may be taken from an output
of the gyroscope when the device 910 is positioned at the starting
position.
[0197] The side 930 of the device 910 may be held against the side
940 of the bar 920 for the start of the procedure as shown in FIG.
9. The device 910 may be slid and/or moved (e.g., manually or via a
motorized or robotic operation) to a position on another side 950
of the bar 920 on the support surface. The device 910 may be hold
against the other side 950 of bar 920 for the end of the procedure
as shown in FIG. 10.
[0198] A second calibration measurement may be taken from an output
of the gyroscope when the device 910 is positioned at the other
side 950 of the bar 920. The gyroscope scale correction may be
computed. In certain representative embodiments, an indication
(e.g., visual and/or audio indication, among others) may be
provided when the scale correction does not exceed a threshold
percentage and/or a second indication (e.g., visual and/or audio
indication, among others) may be provided when the scale correction
exceeds a threshold percentage. In other representative
embodiments, the indication may be accompanied by calibration
information under certain conditions. For example: (1) if the
calibration test is failed, calibration data may be exported from
the device to a collection and/or storage device for further
evaluation; and/or (2) the calibration test is passed, the
calibration data and/or a calibration record may be exported from
the device to store the calibration data and/or calibration
record.
[0199] In certain representative embodiments, the device 910 or the
bar 920 may have more than one flat side surface, for example, to
enable calibration measurements to be taken from known angular
positions for the device 910 in any of a full range of angular
positions from 0.degree. to 360.degree..
[0200] In certain representative embodiments, the device 910 and/or
the bar 920 may have a holding device (not shown) to hold the
device 910 against the bar 920. The holding device may use pressure
suction, a clip, and/or a quick release, among others.
[0201] FIG. 11 is a diagram illustrating a further representative
calibration procedure for a device 910 using inside surfaces of an
N-side polygon (where N=4) calibration device 1120.
[0202] FIG. 12 is a diagram illustrating an additional
representative calibration procedure for the device 910 using
outside surfaces of the N-side polygon calibration device 1220.
[0203] Referring to FIGS. 11 and 12, the calibration procedure may
provide any number of precise rotations. Similar to the calibration
procedure in FIGS. 9 and 10, the device 910 may include: (1) a flat
bottom (and/or points on the bottom that make contact with another
surface (e.g., a support surface) (not shown) to ensure that the
device 910 is not tilted); and (2) at least one flat side 930 that
make contact with (and/or is adjacent to) a first side surface
1140A of an N-sided polygonal calibration device 1120 (where N is
an integer number), for example such that the side surface 930 of
the device 910 and the first side surface 1140A of an N-sided
polygonal calibration device 1120 may form a consistent contact
surface. The consistent contact surface, for example can ensure
precisely known and repeatable angular positions for the device
910.
[0204] The N-sided polygonal calibration device 1120 may be placed
on a flat support surface (e.g., flat table) (not shown). The
N-sided polygonal calibration device 1120 may have four sides as
shown in FIGS. 11 and 12. (e.g., four contact surfaces) that may
match to and/or mate with the flat surface of the device 910 to
ensure that the device 910 is not tilted and is able to be
positioned at precisely known angular positions (at any of: an
angular position of 0.degree. as the starting position or an
angular position that is relative to the starting position such as
0.degree., 90.degree., 180.degree., and/or 270.degree. for a four
sided rectangular calibration device).
[0205] A first calibration measurement may be taken from an output
of the gyroscope when the device 910 is positioned at the starting
position adjacent to the first side 1140A.
[0206] The side 930 of the device 910 may be held against the side
1140A for the start of the procedure as shown in FIG. 11. The
device 910 may be slid and/or moved (e.g., manually or via a
motorized or robotic operation) to a position on a second side
1140B on the support surface. The calibration procedure may be
repeated for this second position adjacent 1140B and may be further
repeated for further positions adjacent 1140C and 1140C.
[0207] The gyroscope scale correction may be computed taking for
example differences between calibration measurements and using any
number of these differences (and/or averaging these differences) to
compute the scale correction. In certain representative
embodiments, a visual and/or an audio indication may be provided
when the scale correction does not exceed a threshold percentage
and/or a second, different visual and/or audio indication may be
provided when the scale correction exceeds the threshold
percentage.
[0208] The calibration associated with N-sided calibration device
1220 is similar to that of the N-sided calibration device 1120 with
the exception that the device 910 moves around an outside (e.g.,
instead of the inside of the N-sided calibration device) such that
calibration measurements occur adjacent to any of: first to fourth
sides 1240A, 1240B, 1240C and/or 1240D.
[0209] In certain representative embodiments, the device 910 and/or
the N-sided polygonal calibration devices 1120 or 1220 may have a
holding device (not shown).
[0210] FIG. 13A is a diagram illustrating a top view of a device
fixture 1310. FIG. 13B is a diagram illustrating a side view of the
device fixture 1310. FIG. 13C is a diagram illustrating a top view
of the device 910. FIG. 13D is a diagram illustrating a side view
of the device 910.
[0211] Referring to FIGS. 13A-13D, the calibration procedure may
use a device fixture 1310 to provide any of: a flat bottom surface
and/or one or more flat side surfaces, for example when the device
910 is irregularly shaped and/or has a continuous curvature, among
others at shown in FIGS. 13C and 13D. The device fixture 1310 may
include one or more bottom and/or side surfaces 1310A and 1310B
(e.g., internal surfaces that may mate with (e.g., may include a
complementary contour to the surfaces of the device 910) and may
include a flat bottom surface 1320A and one or more flat side
surfaces 1320B (e.g., external surfaces that may mate with (e.g.,
may include a complementary contour to the surfaces of the
calibration device (e.g., the bar 920 and/or the N-sided polygonal
calibration device 1120 or 1220) In such representative
embodiments, the device 910 may be placed in the device fixture
1310 which may be used (e.g. placed) against the bar 920 or the
N-sided polygonal calibration device 1120 or 1220.
[0212] These calibration techniques work because they maintain the
constraints of having a rotation around the Z-axis of the device
910, and having an accurate (e.g., very accurate) true rotation of
a known amount (e.g., 0.degree., 90.degree., 180.degree., and/or
270.degree., among others). The difference from a turntable is that
the linear position of the axis of rotation may move, but linear
position changes do not impact the measured angular velocity from a
gyroscope.
[0213] FIG. 14 is a diagram illustrating a docking operation to
show another calibration procedure.
[0214] Referring to FIG. 14, the RAA 200 may be docked in
docking/charging station 300 (e.g., with a fixed orientation for
example based on the docking connector 295 of the RAA 200 coupling
with (e.g., electrically or magnetically couple with) the docking
connector 310 of the docking/charging station 300. When the RAA 200
is not in use, the RAA 200 may be docked at the docking/charging
station 300 by navigating the RAA 200 to a fixed or predefined
position. For example, the docking/charging station 300 and the RAA
200 may be shaped to properly align the RAA 200 with the
docking/charging station 300, for example to ensure proper mating
and/or to ensure a reliable and repeatable positioning (e.g.,
rotational positioning) of the RAA 200 (below a threshold
rotational amount) sufficient for gyroscope scale calibration. The
RAA 200 may undock from docking/charging station 300 and may rotate
one or more predetermined times. The RAA 200 may redock with the
docking/charging station 300. The RAA 200 by redocking in the same
or substantially the same position in the docking/charging station
300 may be rotated a known amount (e.g., 360.degree., 720.degree.,
and/or N.times.360.degree.) for a determination of the gyroscope
scale calibration estimate.
[0215] In certain representative embodiments, the RAA 200 may start
an integration period on a condition that the RAA 200 is docked in
the docking/charging station 300. The RAA 200 may read a gyroscope
output at the start of the integration period. The RAA 200 may
undock from the docking/charging station 300. The RAA 200 may
rotate one or more predetermined rotations. The RAA 200 may redock
with the docking/charging station 300, ending the integration
period on a condition that the device is redocked in the docking
station. The RAA 200 may read the gyroscope output at the end of
the integration period and may estimate the gyroscope scale using
the readings from the gyroscope output.
Other Representative Calibration Device Embodiments
[0216] In certain representative embodiments, an automatic
turntable may be implemented. The device 910 may be mounted to the
turntable, and a motor and motor control system may rotate the
turntable a desired amount (e.g. via a stepper motor, or using one
or more mechanical stops).
[0217] In certain representative embodiments, a manual turntable
may be implemented. The device 910 may be mounted to the turntable
which may have two or more stops that constrain the rotation.
[0218] In certain representative embodiments, the device 910 may
have two or more flat sides. For example, the device 910 may have a
first side and a second side with a known (e.g., accurate) angle
between the first and second sides. The angle may be any known
angle. For example, the device 910 may include two parallel sides.
For calibration, the first side may be placed against a fixed edge
for the starting position, and the second side may be placed
against the same edge for the ending position.
[0219] In certain representative embodiments, the bar 920 may have
two or more flat sides. For the bar calibration procedure, the bar
920 may be any shape that has a first flat side and a second flat
side with a known angle between the first and second sides. The
angle may be any known angle. For example, the device 910 may
include one flat side. For calibration, the one flat side of the
device 910 may be placed against a first side of the bar 920 for
the starting position, and the one flat side of the device 910 may
be placed against a second side of the bar 920 for the ending
position.
[0220] In certain representative embodiments, the device 910 may
have one flat side and the bar may include a single flat side. For
the bar calibration procedure, if there is just one flat side, the
one flat side of the device 910 may be placed against the single
flat side (e.g., fixed edge) at the start position, and the device
910 may be rotated a multiple of 360.degree. and the device placed
against the single flat side (e.g., the fixed edge) again.
[0221] In certain representative embodiments, the device 910 may
include executable code (e.g., a small amount of executable code)
and RAM (e.g., a small amount of RAM) to implement the on-board
calibration and may reduce or eliminate the use of an external test
controller for such a calibration.
[0222] In certain representative embodiments, the device 910 may
not communicate calibration samples out of a device, and may not
writing the calibration records back to the device 910.
[0223] In certain representative embodiments, the device 910 may
not use an encoder or other measurement on the turntable to measure
the true rotation.
[0224] In certain representative embodiments, the bar calibration
may not use a turntable, as the movement may be manually
provided.
[0225] FIG. 15 is a flowchart of a representative method to
estimate a gyroscope scale factor.
[0226] Referring to FIG. 15, the representative method 1500 may
include, at block 1510, rotating the device 910 (or RAA 200) a
plurality of rotations about an axis. At block 1520, the device
910, during the rotating of the device 910, may sample an output of
the gyroscope 240 and an output of the magnetometer 250. At block
1530, the device 910 may determine from magnetometer readings,
which of the samples from the magnetometer are within a first
threshold and that have matching gyroscope headings based on an
integration of the output of the gyroscope, as sample pair
matches.
[0227] At block 1540, for each respective sample pair match, the
device 910 may determine and/or update a composite gyroscope scale
factor using the respective sample pair match. For example, the
composite scale factor may be updated based on an integration of
the gyroscope output over an interval from the time of the first
magnetometer reading (or corresponding sampled gyroscope output) to
the time of the second magnetometer reading (or corresponding
sampled gyroscope output) of the respective sample pair match.
[0228] In certain representative embodiments, the device 910 may
match a set of respective samples from the output of the gyroscope
to a set of corresponding samples from the output of the
magnetometer, for example to generate a plurality of sample pairs,
each sample pair including a sampled output from the gyroscope and
a corresponding reading from the magnetometer.
[0229] In certain representative embodiments, the determining of
the matching gyroscope headings may include the device 910
determining a first gyroscope heading associated with a first
magnetometer reading of a first sample pair and a second gyroscope
heading associated with a second magnetometer reading of a second
sample pair, on condition that the first and second magnetometer
reading are within the first threshold.
[0230] In certain representative embodiments, the device 910 may
determine that the first and second gyroscope heading match on
condition that the first and second gyroscope headings are within a
gyroscope heading threshold.
[0231] For example, the device 910 may determine from the plurality
of sample pairs (e.g., 2-tuples), which of the sample pairs have
readings of the magnetometer 250 that are within a threshold and
that have matching gyroscope headings. These matching sample pairs
(matching 2-tuples) may be referred to hereafter as sample pair
matches. It is contemplated that such sample pair matches may occur
when a magnetometer/gyroscope pair associated with one rotation of
the device 910 and another magnetometer/gyroscope pair associated
with another rotation of the device 910 have matching or
substantially matching gyroscope headings and magnetometer
readings.
[0232] In certain representative embodiments, the matching of the
set of respective samples from the output of the gyroscope 240 to a
set of corresponding samples from the output of the magnetometer
250 may include matching samples taken within a threshold period of
time from the output of the magnetometer 250 and from the output of
the gyroscope 240.
[0233] In certain representative embodiments, the sample pairs
(e.g., each sample pair) may include sampling information
associated with the sampled output of the gyroscope 240 and
corresponding sampling information associated with the output of
the magnetometer 250. For example, the closest samples in time
sampled from the output of the gyroscope 240 and the magnetometer
250 may be paired (e.g., as a 2-tuple).
[0234] In certain representative embodiments, the matching of the
set of respective samples from the output of the gyroscope 240 to a
set of corresponding samples from the output of the magnetometer
250 may include matching samples taken within a threshold period of
time from the output of the magnetometer 250 and from the output of
the gyroscope 240.
[0235] In certain representative embodiments, the sample pair
matches may include sample pairs that have a magnetometer output
difference within the threshold and that have an associated
gyroscope heading difference within another threshold.
[0236] In certain representative embodiments, the sample pair
matches may exclude sample pairs that have a magnetometer output
difference within the threshold and that have an associated
gyroscope heading difference that exceeds another threshold.
[0237] In certain representative embodiments, the
magnetometer/gyroscope pairs associated with one rotation of the
device are a plurality of reference magnetometer/gyroscope
pairs.
[0238] In certain representative embodiments, a reference
magnetometer/gyroscope pair of the plurality of reference sample
pairs may be matched with one or more magnetometer/gyroscope pairs
from one or more other rotations of the device 910.
[0239] In certain representative embodiments, the
magnetometer/gyroscope pairs associated with the one rotation may
be taken at a predetermined number of angular positions within the
one rotation.
[0240] In certain representative embodiments, the device 910 may
sample the output of the magnetometer 250 and the output of the
gyroscope 240 at a rate to have sample pair matches at the
predetermined number of angular positions.
[0241] In certain representative embodiments, the device 910 may
determine whether the output of the magnetometer 250 of a
respective magnetometer/gyroscope pair is within the threshold of
the output of the magnetometer 250 corresponding to the reference
magnetometer/gyroscope pair and on condition that the output of the
magnetometer 250 of the respective magnetometer/gyroscope pair is
within the threshold of the output of the magnetometer 250
corresponding to the reference magnetometer/gyroscope pair, the
device 910 may update an estimate of a component gyroscope scale
for a reference point corresponding to the reference
magnetometer/gyroscope pair, using the respective
magnetometer/gyroscope pair.
[0242] In certain representative embodiments, for each respective
subsequent magnetometer/gyroscope pair for which the output of the
magnetometer 250 is closer to the output of the magnetometer 250
corresponding to the reference point, the device 910 may update the
estimate of the component gyroscope scale for that reference point
using the respective subsequent magnetometer/gyroscope pair.
[0243] In certain representative embodiments, the device may
determine the magnetometer/gyroscope pairs by assigning an index to
each reference point; setting a counter to the index corresponding
to one of the reference points for which the output of the
magnetometer 250 of a current sample pair is closest, for each
subsequent magnetometer/gyroscope pair, determining whether the
output of the magnetometer 250 is closer to the output of the
magnetometer 250 from the current reference point or a next
reference point; and/or on condition that the sampled output of the
magnetometer 250 of a subsequent magnetometer/gyroscope pair is
closer to the output from the magnetometer 250 corresponding to the
next reference point than to the current reference point,
incrementing the counter.
[0244] In certain representative embodiments, the device 910 may
update the composite gyroscope scale factor using the respective
sample pair match by: determining a component gyroscope scale
factor for each gyroscope heading associated with the respective
sample pair match; and/or generating the composite gyroscope scale
factor by any of: averaging or weighing the component gyroscope
scale estimates associated with different gyroscope headings.
[0245] In certain representative embodiments, the device 910 may
compensate the output of the gyroscope 240 for any tilt between the
axis of rotation of the device 910 and a sensing axis of the
gyroscope 240.
[0246] In certain representative embodiments, the device 910 may
compensate by determining a zero-gravity offset (ZGO) of an
accelerometer 260 including a tilt angle between the accelerometer
260 and the device 910; and/or correcting the gyroscope output
based on the tilt angle.
[0247] In certain representative embodiments, the device 910 may
compensate by: determining a norm of an angular velocity detected
by the gyroscope 240; and modifying the output of the gyroscope due
to a tilt angle by using the norm as the z component of the angular
velocity.
[0248] In certain representative embodiments, the rotating of the
device 910 the plurality of rotations may include rotating the
device 910 in a first direction a first portion of the plurality of
rotations; and/or rotating the device 910 in a second direction a
second portion of the plurality of rotations.
[0249] In certain representative embodiments, the sample pair match
may include: (1) sampling information associated with a
magnetometer reading of a first magnetometer/gyroscope pair; (2)
sampling information associated with a sampled output of the
gyroscope of the first magnetometer/gyroscope pair; (3) sample
information associated with a magnetometer reading of a second
magnetometer/gyroscope pair; and (4) sample information associated
with a sampled output of the gyroscope of the second
magnetometer/gyroscope pair. In other representative embodiments,
the sample pair match may include (e.g., may only include): (1)
sampling information associated with a first magnetometer reading;
and (2) sample information associated with a second magnetometer
reading.
[0250] FIG. 16 is a flowchart of another representative method to
estimate a gyroscope scale.
[0251] Referring to FIG. 16, the representative method 1600 may
include, at block 1610, a device 910 receiving a first input
indicating that the device 910 is in a first angular position, as a
start position to estimate the gyroscope scale. At block 1620, the
device 910 may start an integration period on a condition that the
first input is received. At block 1630, the device 910 may sample a
set of gyroscope outputs during the integration period. At block
1640, the device 910 may receive a second input indicating that the
device 910 is in a second, preconfigured angular position, relative
to the starting position, as a final position. At block 1650, the
device 910 may end the integration period, on a condition that the
second input is received. At block 1660, the device 910 may
estimate the gyroscope scale using samples of the set of gyroscope
outputs sampled during the integration period. For example, the
estimation of the gyroscope scale may include averaging one or more
samples taken while the device 910 at the start position,
determining, by the device 910, a zero rate offset (ZRO) from the
averaged one or more samples taken while the device 910 is at the
start position and/or compensating, by the device 910, for the ZRO
in the estimation of the gyroscope scale.
[0252] In certain representative embodiments, the device 910 may
present to an external entity, a first indication that the device
910 is ready to be moved to another position or the final position,
after the end of the integration period and/or may present to the
external entity, a second indication of whether the estimate of
gyroscope scale is within a threshold of a reference gyroscope
scale.
[0253] In certain representative embodiments, the device 910 may
send any of: (1) data associated with the samples sampled during
the integration period; (2) estimation information in accordance
with the estimation of the gyroscope scale; (3) error codes
indicating a type of error associated with a gyroscope scale
estimation operation; and/or (4) a calibration record.
[0254] FIG. 17 is a flowchart of an additional representative
method to estimate a gyroscope scale.
[0255] Referring to FIG. 17, the representative method 1700 may
include, at block 1710, a device 910 determining that the device
910 is in a first angular position, as a start position. At block
1720, the device 910 may start an integration period based on the
determination that the device 910 is in the start position. At
block 1730, the device 910 may sample a set of gyroscope outputs
during the integration period. At block 1740, the device 910 may
determine that the device 910 is in a second, preconfigured angular
position, relative to the starting position, as a final position
based on samples taken from the gyroscope 240 and/or an
accelerometer 260. At block 1750, the device 910 may end the
integration period based on the determination that the device is in
the final position. At block 1760, the device 910 may estimate the
gyroscope scale using samples of the set of gyroscope outputs
sampled during the integration period.
[0256] In certain representative embodiments, the device 910 may
determine that the device 910 is in the start position based on
samples from the gyroscope 240 and/or the accelerometer 260 after
receiving an indication that the device 910 is in a calibration
mode.
[0257] FIG. 18 is a flowchart of a further representative method to
estimate a gyroscope scale.
[0258] Referring to FIG. 18, the representative method 1800 may
include, at block 1810, a device 910 starting an integration period
on a condition that the device 910 is docked in a docking station
300. At block 1820, the device 910 may read a gyroscope output at
the start of the integration period. At block 1930, the device 910
may undock from the docking station 300. At block 1940, the device
910 may rotate one or more predetermined rotations. At block 1950,
the device 910 may redock with the docking station 300. At block
1960, the device 910 may end the integration period on a condition
that the device 910 is redocked in the docking station 300. At
block 1970, the device 910 may read the gyroscope output at the end
of the integration period. At block 1980, the device 910 may
estimate the gyroscope scale using the readings from the gyroscope
output.
[0259] In certain representative embodiments, the device 910 may be
any of a robotic device, a robotic vacuum cleaner, an Inertial
Measurement unit (IMU), a Timing & IMU (TIMU), a mobile device,
a head mounted display, a WTRU and/or a smartphone.
[0260] In certain representative embodiments, a calibration device
920, 1120 and/or 1220 may be used to estimate a gyroscope scale of
a device 910 (e.g., a test device). The calibration device 920,
1120 and/or 1220 may include a member 920 configured with first and
second parallel sides 940:950, 1140A:1140C, 1140B:1140D,
1240A:1240C, and 1240B:1240D. The first parallel side (e.g., side
940) may be configured to mate with a first side (e.g., side 930)
of the test device 910 to provide a known angular position for the
test device 910, as a start position for the test device 910. The
second parallel side (e.g. side 950) may be configured to mate with
the first side (e.g., side 930 of the test device 910 to provide a
second, known angular position for the test device 910, as a final
position for the test device 910. For example, a difference between
the start position and the final position of the test device 910
may represent a 180.degree. rotation of the test device 910.
[0261] In certain representative embodiments, a calibration device
1120 and/or 1220 may be used to estimate a gyroscope scale of a
test device 910. The calibration device 1120 and/or 1220 may
include a first member (e.g., first member 1140A or 1240A) that may
include a least one side. The calibration device 1120 and/or 1220
may include a second member (e.g., second member 1140B or 1240B)
including at least one side at a known angle from the side of the
first member 1140A or 1240A. The side of the first member 1140A or
1240A may be configured to mate with a first side 930 of the test
device 910 to provide a known angular position for the test device
910, as a start position for the test device 910, and the side of
the second member 1140B or 1240B may be configured to mate with the
first side 930 of the test device 910 to provide a second, known
angular position for the test device 910, as a final position for
the test device 910. For example, a difference between the start
position and the final position of the test device 910 may
represent a predetermined and/or preconfigured rotation of the test
device 910.
[0262] Systems and methods for processing data according to
representative embodiments may be performed by one or more
processors executing sequences of instructions contained in a
memory device. Such instructions may be read into the memory device
from other computer-readable mediums such as secondary data storage
device(s). Execution of the sequences of instructions contained in
the memory device causes the processor to operate, for example, as
described above. In alternative embodiments, hard-wire circuitry
may be used in place of or in combination with software
instructions to implement the present invention. Such software may
run on a processor which is housed within an RAA and/or other
mobile device remotely. In the later a case, data may be
transferred via wireline or wirelessly between the RAA or other
mobile device containing the sensors and the remote device
containing the processor which runs the software which performs the
scale estimation and compensation as described above. According to
other representative embodiments, some of the processing described
above with respect to bias estimation may be performed in the
device containing the sensors, while the remainder of the
processing may be performed in a second device after receipt of the
partially processed data from the device containing the
sensors.
[0263] Although the foregoing representative embodiments relate to
sensing packages including one or more rotational sensors and an
accelerometer, bias estimation techniques according to these
representative embodiments are not limited to only these types of
sensors. Instead bias estimation techniques as described herein can
be applied to devices which include, for example, only
accelerometer(s), optical and inertial sensors (e.g., a rotational
sensor, a gyroscope or an accelerometer), a magnetometer and an
inertial sensor (e.g., a rotational sensor, a gyroscope or an
accelerometer), a magnetometer and an optical sensor (e.g. a
camera, one or more photodiodes, one or more phototransistors), or
other sensor combinations. Additionally, although certain
representative embodiments described herein relate to gyroscope
scale calibration in the context of RAA and applications, such
techniques are not so limited and may be employed in methods and
devices associated with other robotic device, Inertial Measurement
units (IMUs), Timing & IMUs (TIMUs), mobile devices, head
mounted displays, WTRUs and/or smartphones, among others.
[0264] Although features and elements are described above in
particular combinations, one of ordinary skill in the art will
appreciate that each feature or element can be used alone or in any
combination with the other features and elements. In addition, the
methods described herein may be implemented in a computer program,
software, or firmware incorporated in a computer readable medium
for execution by a computer or processor. Examples of
non-transitory computer-readable storage media include, but are not
limited to, a read only memory (ROM), random access memory (RAM), a
register, cache memory, semiconductor memory devices, magnetic
media such as internal hard disks and removable disks,
magneto-optical media, and optical media such as CD-ROM disks, and
digital versatile disks (DVDs). A processor in association with
software may be used to implement a radio frequency transceiver for
use in a WTRU 102, UE, terminal, base station, RNC, or any host
computer.
[0265] Moreover, in the embodiments described above, processing
platforms, computing systems, controllers, and other devices
containing processors are noted. These devices may contain at least
one Central Processing Unit ("CPU") and memory. In accordance with
the practices of persons skilled in the art of computer
programming, reference to acts and symbolic representations of
operations or instructions may be performed by the various CPUs and
memories. Such acts and operations or instructions may be referred
to as being "executed," "computer executed" or "CPU executed."
[0266] One of ordinary skill in the art will appreciate that the
acts and symbolically represented operations or instructions
include the manipulation of electrical signals by the CPU. An
electrical system represents data bits that can cause a resulting
transformation or reduction of the electrical signals and the
maintenance of data bits at memory locations in a memory system to
thereby reconfigure or otherwise alter the CPU's operation, as well
as other processing of signals. The memory locations where data
bits are maintained are physical locations that have particular
electrical, magnetic, optical, or organic properties corresponding
to or representative of the data bits. It should be understood that
the representative embodiments are not limited to the
above-mentioned platforms or CPUs and that other platforms and CPUs
may support the provided methods.
[0267] The data bits may also be maintained on a computer readable
medium including magnetic disks, optical disks, and any other
volatile (e.g., Random Access Memory ("RAM")) or non-volatile
(e.g., Read-Only Memory ("ROM")) mass storage system readable by
the CPU. The computer readable medium may include cooperating or
interconnected computer readable medium, which exist exclusively on
the processing system or are distributed among multiple
interconnected processing systems that may be local or remote to
the processing system. It is understood that the representative
embodiments are not limited to the above-mentioned memories and
that other platforms and memories may support the described
methods.
[0268] In an illustrative embodiment, any of the operations,
processes, etc. described herein may be implemented as
computer-readable instructions stored on a computer-readable
medium. The computer-readable instructions may be executed by a
processor of a mobile unit, a network element, and/or any other
computing device.
[0269] There is little distinction left between hardware and
software implementations of aspects of systems. The use of hardware
or software is generally (but not always, in that in certain
contexts the choice between hardware and software may become
significant) a design choice representing cost vs. efficiency
tradeoffs. There may be various vehicles by which processes and/or
systems and/or other technologies described herein may be effected
(e.g., hardware, software, and/or firmware), and the preferred
vehicle may vary with the context in which the processes and/or
systems and/or other technologies are deployed. For example, if an
implementer determines that speed and accuracy are paramount, the
implementer may opt for a mainly hardware and/or firmware vehicle.
If flexibility is paramount, the implementer may opt for a mainly
software implementation. Alternatively, the implementer may opt for
some combination of hardware, software, and/or firmware.
[0270] The foregoing detailed description has set forth various
embodiments of the devices and/or processes via the use of block
diagrams, flowcharts, and/or examples. Insofar as such block
diagrams, flowcharts, and/or examples contain one or more functions
and/or operations, it will be understood by those within the art
that each function and/or operation within such block diagrams,
flowcharts, or examples may be implemented, individually and/or
collectively, by a wide range of hardware, software, firmware, or
virtually any combination thereof. Suitable processors include, by
way of example, a general purpose processor, a special purpose
processor, a conventional processor, a digital signal processor
(DSP), a plurality of microprocessors, one or more microprocessors
in association with a DSP core, a controller, a microcontroller,
Application Specific Integrated Circuits (ASICs), Application
Specific Standard Products (ASSPs); Field Programmable Gate Arrays
(FPGAs) circuits, any other type of integrated circuit (IC), and/or
a state machine.
[0271] Although features and elements are provided above in
particular combinations, one of ordinary skill in the art will
appreciate that each feature or element can be used alone or in any
combination with the other features and elements. The present
disclosure is not to be limited in terms of the particular
embodiments described in this application, which are intended as
illustrations of various aspects. Many modifications and variations
may be made without departing from its spirit and scope, as will be
apparent to those skilled in the art. No element, act, or
instruction used in the description of the present application
should be construed as critical or essential to the invention
unless explicitly provided as such. Functionally equivalent methods
and apparatuses within the scope of the disclosure, in addition to
those enumerated herein, will be apparent to those skilled in the
art from the foregoing descriptions. Such modifications and
variations are intended to fall within the scope of the appended
claims. The present disclosure is to be limited only by the terms
of the appended claims, along with the full scope of equivalents to
which such claims are entitled. It is to be understood that this
disclosure is not limited to particular methods or systems.
[0272] It is also to be understood that the terminology used herein
is for the purpose of describing particular embodiments only, and
is not intended to be limiting. As used herein, when referred to
herein, the terms "station" and its abbreviation "STA", "user
equipment" and its abbreviation "UE" may mean (i) a wireless
transmit and/or receive unit (WTRU), such as described infra; (ii)
any of a number of embodiments of a WTRU, such as described infra;
(iii) a wireless-capable and/or wired-capable (e.g., tetherable)
device configured with, inter alia, some or all structures and
functionality of a WTRU, such as described infra; (iii) a
wireless-capable and/or wired-capable device configured with less
than all structures and functionality of a WTRU, such as described
infra; or (iv) the like. Details of an example WTRU, which may be
representative of any UE recited herein, are provided below with
respect to FIGS. 1A-1D.
[0273] In certain representative embodiments, several portions of
the subject matter described herein may be implemented via
Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs), digital signal processors (DSPs),
and/or other integrated formats. However, those skilled in the art
will recognize that some aspects of the embodiments disclosed
herein, in whole or in part, may be equivalently implemented in
integrated circuits, as one or more computer programs running on
one or more computers (e.g., as one or more programs running on one
or more computer systems), as one or more programs running on one
or more processors (e.g., as one or more programs running on one or
more microprocessors), as firmware, or as virtually any combination
thereof, and that designing the circuitry and/or writing the code
for the software and or firmware would be well within the skill of
one of skill in the art in light of this disclosure. In addition,
those skilled in the art will appreciate that the mechanisms of the
subject matter described herein may be distributed as a program
product in a variety of forms, and that an illustrative embodiment
of the subject matter described herein applies regardless of the
particular type of signal bearing medium used to actually carry out
the distribution. Examples of a signal bearing medium include, but
are not limited to, the following: a recordable type medium such as
a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a
computer memory, etc., and a transmission type medium such as a
digital and/or an analog communication medium (e.g., a fiber optic
cable, a waveguide, a wired communications link, a wireless
communication link, etc.).
[0274] The herein described subject matter sometimes illustrates
different components contained within, or connected with, different
other components. It is to be understood that such depicted
architectures are merely examples, and that in fact many other
architectures may be implemented which achieve the same
functionality. In a conceptual sense, any arrangement of components
to achieve the same functionality is effectively "associated" such
that the desired functionality may be achieved. Hence, any two
components herein combined to achieve a particular functionality
may be seen as "associated with" each other such that the desired
functionality is achieved, irrespective of architectures or
intermediate components. Likewise, any two components so associated
may also be viewed as being "operably connected", or "operably
coupled", to each other to achieve the desired functionality, and
any two components capable of being so associated may also be
viewed as being "operably couplable" to each other to achieve the
desired functionality. Specific examples of operably couplable
include but are not limited to physically mateable and/or
physically interacting components and/or wirelessly interactable
and/or wirelessly interacting components and/or logically
interacting and/or logically interactable components.
[0275] With respect to the use of substantially any plural and/or
singular terms herein, those having skill in the art can translate
from the plural to the singular and/or from the singular to the
plural as is appropriate to the context and/or application. The
various singular/plural permutations may be expressly set forth
herein for sake of clarity.
[0276] It will be understood by those within the art that, in
general, terms used herein, and especially in the appended claims
(e.g., bodies of the appended claims) are generally intended as
"open" terms (e.g., the term "including" should be interpreted as
"including but not limited to," the term "having" should be
interpreted as "having at least," the term "includes" should be
interpreted as "includes but is not limited to," etc.). It will be
further understood by those within the art that if a specific
number of an introduced claim recitation is intended, such an
intent will be explicitly recited in the claim, and in the absence
of such recitation no such intent is present. For example, where
only one item is intended, the term "single" or similar language
may be used. As an aid to understanding, the following appended
claims and/or the descriptions herein may contain usage of the
introductory phrases "at least one" and "one or more" to introduce
claim recitations. However, the use of such phrases should not be
construed to imply that the introduction of a claim recitation by
the indefinite articles "a" or "an" limits any particular claim
containing such introduced claim recitation to embodiments
containing only one such recitation, even when the same claim
includes the introductory phrases "one or more" or "at least one"
and indefinite articles such as "a" or "an" (e.g., "a" and/or "an"
should be interpreted to mean "at least one" or "one or more"). The
same holds true for the use of definite articles used to introduce
claim recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, those skilled in
the art will recognize that such recitation should be interpreted
to mean at least the recited number (e.g., the bare recitation of
"two recitations," without other modifiers, means at least two
recitations, or two or more recitations). Furthermore, in those
instances where a convention analogous to "at least one of A, B,
and C, etc." is used, in general such a construction is intended in
the sense one having skill in the art would understand the
convention (e.g., "a system having at least one of A, B, and C"
would include but not be limited to systems that have A alone, B
alone, C alone, A and B together, A and C together, B and C
together, and/or A, B, and C together, etc.). In those instances
where a convention analogous to "at least one of A, B, or C, etc."
is used, in general such a construction is intended in the sense
one having skill in the art would understand the convention (e.g.,
"a system having at least one of A, B, or C" would include but not
be limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, and/or A, B, and C
together, etc.). It will be further understood by those within the
art that virtually any disjunctive word and/or phrase presenting
two or more alternative terms, whether in the description, claims,
or drawings, should be understood to contemplate the possibilities
of including one of the terms, either of the terms, or both terms.
For example, the phrase "A or B" will be understood to include the
possibilities of "A" or "B" or "A and B." Further, the terms "any
of" followed by a listing of a plurality of items and/or a
plurality of categories of items, as used herein, are intended to
include "any of," "any combination of," "any multiple of," and/or
"any combination of" multiples of the items and/or the categories
of items, individually or in conjunction with other items and/or
other categories of items. Moreover, as used herein, the term "set"
or "group" is intended to include any number of items, including
zero. Additionally, as used herein, the term "number" is intended
to include any number, including zero.
[0277] In addition, where features or aspects of the disclosure are
described in terms of Markush groups, those skilled in the art will
recognize that the disclosure is also thereby described in terms of
any individual member or subgroup of members of the Markush
group.
[0278] As will be understood by one skilled in the art, for any and
all purposes, such as in terms of providing a written description,
all ranges disclosed herein also encompass any and all possible
subranges and combinations of subranges thereof .DELTA.ny listed
range can be easily recognized as sufficiently describing and
enabling the same range being broken down into at least equal
halves, thirds, quarters, fifths, tenths, etc. As a non-limiting
example, each range discussed herein may be readily broken down
into a lower third, middle third and upper third, etc. As will also
be understood by one skilled in the art all language such as "up
to," "at least," "greater than," "less than," and the like includes
the number recited and refers to ranges which can be subsequently
broken down into subranges as discussed above. Finally, as will be
understood by one skilled in the art, a range includes each
individual member. Thus, for example, a group having 1-3 cells
refers to groups having 1, 2, or 3 cells. Similarly, a group having
1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so
forth.
[0279] Moreover, the claims should not be read as limited to the
provided order or elements unless stated to that effect. In
addition, use of the terms "means for" in any claim is intended to
invoke 35 U.S.C. .sctn. 112, 6 or means-plus-function claim format,
and any claim without the terms "means for" is not so intended.
[0280] A processor in association with software may be used to
implement a radio frequency transceiver for use in a wireless
transmit receive unit (WTRU), user equipment (UE), terminal, base
station, Mobility Management Entity (MME) or Evolved Packet Core
(EPC), or any host computer. The WTRU may be used m conjunction
with modules, implemented in hardware and/or software including a
Software Defined Radio (SDR), and other components such as a
camera, a video camera module, a videophone, a speakerphone, a
vibration device, a speaker, a microphone, a television
transceiver, a hands free headset, a keyboard, a Bluetooth.RTM.
module, a frequency modulated (FM) radio unit, a Near Field
Communication (NFC) Module, a liquid crystal display (LCD) display
unit, an organic light-emitting diode (OLED) display unit, a
digital music player, a media player, a video game player module,
an Internet browser, and/or any Wireless Local Area Network (WLAN)
or Ultra Wide Band (UWB) module.
[0281] Although the invention has been described in terms of
communication systems, it is contemplated that the systems may be
implemented in software on microprocessors/general purpose
computers (not shown). In certain embodiments, one or more of the
functions of the various components may be implemented in software
that controls a general-purpose computer.
[0282] In addition, although the invention is illustrated and
described herein with reference to specific embodiments, the
invention is not intended to be limited to the details shown.
Rather, various modifications may be made in the details within the
scope and range of equivalents of the claims and without departing
from the invention.
[0283] Throughout the disclosure, one of skill understands that
certain representative embodiments may be used in the alternative
or in combination with other representative embodiments.
[0284] Although features and elements are described above in
particular combinations, one of ordinary skill in the art will
appreciate that each feature or element can be used alone or in any
combination with the other features and elements. In addition, the
methods described herein may be implemented in a computer program,
software, or firmware incorporated in a computer readable medium
for execution by a computer or processor. Examples of
non-transitory computer-readable storage media include, but are not
limited to, a read only memory (ROM), random access memory (RAM), a
register, cache memory, semiconductor memory devices, magnetic
media such as internal hard disks and removable disks,
magneto-optical media, and optical media such as CD-ROM disks, and
digital versatile disks (DVDs). A processor in association with
software may be used to implement a radio frequency transceiver for
use in a WTRU, UE, terminal, base station, RNC, or any host
computer.
[0285] Moreover, in the embodiments described above, processing
platforms, computing systems, controllers, and other devices
containing processors are noted. These devices may contain at least
one Central Processing Unit ("CPU") and memory. In accordance with
the practices of persons skilled in the art of computer
programming, reference to acts and symbolic representations of
operations or instructions may be performed by the various CPUs and
memories. Such acts and operations or instructions may be referred
to as being "executed," "computer executed" or "CPU executed."
[0286] One of ordinary skill in the art will appreciate that the
acts and symbolically represented operations or instructions
include the manipulation of electrical signals by the CPU. An
electrical system represents data bits that can cause a resulting
transformation or reduction of the electrical signals and the
maintenance of data bits at memory locations in a memory system to
thereby reconfigure or otherwise alter the CPU's operation, as well
as other processing of signals. The memory locations where data
bits are maintained are physical locations that have particular
electrical, magnetic, optical, or organic properties corresponding
to or representative of the data bits.
[0287] The data bits may also be maintained on a computer readable
medium including magnetic disks, optical disks, and any other
volatile (e.g., Random Access Memory ("RAM")) or non-volatile
("e.g., Read-Only Memory ("ROM")) mass storage system readable by
the CPU. The computer readable medium may include cooperating or
interconnected computer readable medium, which exist exclusively on
the processing system or are distributed among multiple
interconnected processing systems that may be local or remote to
the processing system. It is understood that the representative
embodiments are not limited to the above-mentioned memories and
that other platforms and memories may support the described
methods.
[0288] Suitable processors include, by way of example, a general
purpose processor, a special purpose processor, a conventional
processor, a digital signal processor (DSP), a plurality of
microprocessors, one or more microprocessors in association with a
DSP core, a controller, a microcontroller, Application Specific
Integrated Circuits (ASICs), Application Specific Standard Products
(ASSPs); Field Programmable Gate Arrays (FPGAs) circuits, any other
type of integrated circuit (IC), and/or a state machine.
[0289] Although the invention has been described in terms of
communication systems, it is contemplated that the systems may be
implemented in software on microprocessors/general purpose
computers (not shown). In certain embodiments, one or more of the
functions of the various components may be implemented in software
that controls a general-purpose computer.
[0290] In addition, although the invention is illustrated and
described herein with reference to specific embodiments, the
invention is not intended to be limited to the details shown.
Rather, various modifications may be made in the details within the
scope and range of equivalents of the claims and without departing
from the invention.
* * * * *