U.S. patent application number 11/559999 was filed with the patent office on 2007-03-29 for system and method for aggregating information to determine a user's location.
Invention is credited to Anand Naga Babu, Abraham S. Heifets, Adam Krauszer, Roy Paterson, Brian Lee White Eagle.
Application Number | 20070072626 11/559999 |
Document ID | / |
Family ID | 25097490 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070072626 |
Kind Code |
A1 |
Babu; Anand Naga ; et
al. |
March 29, 2007 |
System and Method for Aggregating Information to Determine a User's
Location
Abstract
Provided is a system and method that acquires and aggregates
information to determine the location of a user. Information from
multiple sources is collected and evaluated. Location sources
include mobile electronic devices such as mobile telephones, cell
phones, hand-held computers, personal digital assistants, pagers,
Global Positioning System (GPS) devices, and other pervasive
computing devices. Satellite-based or network-based positioning
technologies make ti possible to determine the geographic location
of these wireless electronic devices and their coresponding user.
Location sources also include computer-based models, schedules or
calendars that gave a particular user's expected location depending
on the date and time. Provided is a method for aggregating
information to determine a user's location. Also provided is a
system for executing the claimed method. Also provided is a service
for providing the claimed method.
Inventors: |
Babu; Anand Naga; (Peoria,
IL) ; Heifets; Abraham S.; (Menlo Park, CA) ;
Krauszer; Adam; (Ithaca, NY) ; Paterson; Roy;
(Austin, TX) ; White Eagle; Brian Lee; (Austin,
TX) |
Correspondence
Address: |
Greg Goshorn, P.C.
9600 Escarpment
auite 745-9
AUSTIN
TX
78749
US
|
Family ID: |
25097490 |
Appl. No.: |
11/559999 |
Filed: |
November 15, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09773194 |
Jan 31, 2001 |
7139252 |
|
|
11559999 |
Nov 15, 2006 |
|
|
|
Current U.S.
Class: |
455/456.1 |
Current CPC
Class: |
H04L 29/06 20130101;
H04L 67/18 20130101; H04L 67/20 20130101; H04L 69/329 20130101 |
Class at
Publication: |
455/456.1 |
International
Class: |
H04Q 7/20 20060101
H04Q007/20 |
Claims
1. A method of controlling a power delivery system, comprising:
operating a system comprising a plurality of power cells that are
electrically connected to a first transformer comprising one or
more primary windings and a plurality of secondary windings such
that each cell is electrically connected to one of the secondary
windings and a plurality of the secondary windings are
phase-shifted with respect to the primary windings, wherein each
cell includes a plurality of switching devices; and controlling the
timing of activation of the switching devices within each cell so
that an effective frequency of the activation for all of the cells
as reflected to the primary is at least three times greater than
the switching frequency of any individual cell.
2. The method of claim 1, wherein the controlling does not require
the use of a synchronizing clock signal.
3. The method of claim 1, wherein the controlling comprises:
determining a carrier offset angle; passing the carrier offset
angle to the first power cell; and synchronizing, by the first
power cell, a carrier signal to the first secondary voltage based
on the carrier offset angle.
4. The method of claim 3, further comprising, synchronizing, by
each additional cell in the system, an additional carrier signal to
a secondary voltage for each additional cell.
5. The method of claim 3, wherein the carrier signals for each cell
are interdigitated so that they are distributed substantially
evenly when reflected toward the primary windings of the source
transformer.
6. The method of claim 3, wherein the carrier signal also controls
the timing of implementation of commands that control the switching
devices.
7. The method of claim 6, wherein the switching devices are part of
an AC-to-DC converter portion of the cell.
8. The method of claim 6, wherein when a plurality of the cells
determine that switching commands must be implemented, the carrier
offset angle for each cell ensures that the commands are
effectively interdigitated as reflected to the primary of the
transformer.
9. The method of claim 8, wherein: a command is implemented by the
first power cell at a frequency substantially equal to a multiple
of a fundamental frequency.
10. The method of claim 3, wherein the carrier offset angle
represents a phase relationship between the carrier signal of the
first cell and the first secondary voltage.
11. The method of claim 3, further comprising: operating a second
system comprising a second transformer and a second plurality of
power cells, wherein: the second transformer comprises one or more
primary windings and a plurality of secondary windings; the primary
windings of the second transformer are electrically connected to
the primary windings of the source transformer at a common point;
and each power cell in the second system generates a carrier
signal; wherein the carrier signals for each cell in the second
system are interdigitated so that they are distributed
substantially evenly when reflected toward the primary windings of
the secondary transformer.
12. A method of operating a power delivery system, comprising:
operating a system comprising a plurality of power cells that are
electrically connected to a first transformer comprising one or
more primary windings and a plurality of secondary windings such
that each cell is electrically connected to one of the secondary
windings and a plurality of the secondary windings are
phase-shifted with respect to the primary windings, wherein each
cell includes a plurality of switching devices; wherein a first
secondary winding is electrically connected to deliver power to a
first power cell; determining a carrier offset angle; passing the
first carrier offset angle to the first power cell; synchronizing,
by the first power cell, a carrier signal to the first secondary
voltage based on the first carrier offset angle; and for a second
cell that is connected to a second secondary winding of the source
transformer, wherein the second secondary winding has a voltage
that is phase-shifted with respect the voltage of the first
secondary winding, synchronizing a second carrier signal to the
second secondary voltage using a second carrier offset angle.
13. The method of claim 12, wherein the carrier signals for each
cell that is electrically connected to the source transformer are
interdigitated so that they are distributed substantially evenly
when reflected toward the primary windings of the source
transformer.
14. The method of claim 12, wherein: the carrier signal for each
cell also controls the timing of implementation of commands that
control the switching devices; and the synchronizing controls the
timing of activation of the switching devices within each cell so
that an effective frequency of the activation for all of the cells
as reflected to the primary is at least three times greater than
the switching frequency of any individual cell.
15. The method of claim 14, wherein the commands control switching
devices that are part of an AC-to-DC converter portion of each
cell.
16. The method of claim 14, wherein when a plurality of the cells
determine that switching commands must be implemented, the commands
are effectively interdigitated as reflected to the primary of the
transformer.
17. The method of claim 14, wherein: a command is implemented by
the first power cell at a frequency substantially equal to a
multiple of a fundamental frequency.
18. The method of claim 12, wherein the carrier offset angle
represents a phase relationship between the carrier signal of the
first cell and the first secondary voltage.
19. A method of operating a power delivery system, comprising:
operating a system comprising a plurality of power cells that are
electrically connected to a multi-winding machine comprising one or
more primary windings and a plurality of secondary windings such
that each cell is electrically connected to one of the secondary
windings and a plurality of the secondary windings are
phase-shifted with respect to the primary windings; determining,
for each cell in a set of the power cells, a carrier offset angle;
synchronizing, by the each cell in the set, a carrier signal to the
secondary voltage for the cell based on the carrier offset angle
determined for the cell; and wherein the carrier signal for each
cell controls the timing of operation of switching devices within
the cell.
20. The method of claim 19 wherein a switching frequency for all of
the cells is at least three times greater than a switching
frequency for any individual cell's carrier signal.
21. A power delivery system, comprising: a plurality of power cells
that are electrically connected to a first transformer comprising
one or more primary windings and a plurality of secondary windings
such that each cell is electrically connected to one of the
secondary windings and a plurality of the secondary windings are
phase-shifted with respect to the primary windings; and a plurality
of switching devices included within each cell is timed, wherein
timing of activation of the switching devices within each cell so
that an effective frequency of the activation for all of the cells
as reflected to the primary is at least three times greater than
the switching frequency of any individual cell.
22. The system of claim 21, wherein a synchronizing clock signal is
not required for activation of the switching devices.
23. The system of claim 21, wherein the effective frequency is
determined by a carrier offset angle, passing the carrier offset
angle to the first power cell, and synchronizing, by the first
power cell, a carrier signal to the first secondary voltage based
on the carrier offset angle.
24. The system of claim 21, wherein each cell includes a carrier
signal interdigitated so that they are distributed substantially
evenly when reflected toward the primary windings of the source
transformer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to a communication of an
application entitled "System and Method for Aggregating Information
to Determine Users' Location," Ser. No. 09/773,194, filed Jan. 31,
2001, assigned to the assignee of the present application, and
herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to information
handling systems and more particularly to methods and systems that
aggregate information to determine a user's location.
BACKGROUND OF THE INVENTION
[0003] Mobile, wireless electronic devices such as mobile
telephones, personal digital assistants, and Global Positioning
System (GPS) devices, have become very popular, and their use has
become very common. It is common for one person to use two or more
of these devices. These mobile device are a subset of a group of
devices that are sometimes called "pervasive computing" devices.
The term "pervasive computing" is used because systems with
microprocessors are now found in any array of devices that
previously were largely untouched by a computer technology. These
pervasive computing devices include mobile devices such as cell
phones and automobile components. Pervasive comprising devices
often include a microprocessor and associated volatile and
non-volatile memory, input means, output means, and interfaces,
such as a network interface or modem, providing a link to other
computing devices.
[0004] These pervasive computing devices are information handling
systems, designated to give independent computing power to a single
user, or a group of users in the case of networked pervasive
computing devices. Pervasive computing devices may also include one
or more input/output devices which are coupled to the
microprocessor and which perform specialized functions (e.g.
modems, sound and video devices, or specialized communication
devices). Pervasive computing devices are often linked to computing
systems and other pervasive computing devices using a network, such
as a local area network (LAN), wide area network (WAN), or the
Internet.
[0005] Satellite-based or network-based positioning technologies
make it possible to determine the geographic location of mobile
pervasive computing devices (e.g. location-based services for users
of mobile telephones use such positioning technologies). One
problem is that location information from one source may be
inconsistent with information from another source. For example, a
husband and wife may share a tracking device that is embedded in
their car. in addition, the husband may have a location-aware
mobile phone. The wife may use a car to drive to the wife's office,
after giving the husband the ride to his office. Then information
from the mobile phone, indicating that the husband is at his
office, will be inconsistent with information from the tracking
device in the car, indicating that the husband is at the wife's
office.
[0006] Such an inconsistency could cause significant practical
problems. To continue the example, the husband's employer may use
location information from employees mobile electronic devices to
determine the employees' location. The system would help the
employer make good decisions about dispatching employees to make
sales calls or service calls. However, this system could be
defeated when information from one source indicates that the
husband is at his office, and information from another source
indicates that the husband is at the wife's office.
[0007] The inconsistency would be difficult to resolve, without
additional information about the people involved, their schedules,
and how they are associated with various mobile devices. To make
the best use of these positioning technologies, it would be
important to make use of all available information, from multiple
sources, to determine users' locations. Thus there is a need for
methods and systems that acquire, aggregate, and evaluate location
information for multiple sources. There is a need for methods and
systems that go beyond just locating a mobile device, to also
include information about people, their schedules, and their
various devices.
SUMMARY OF THE INVENTION
[0008] The present invention is a system and method that acquires
and aggregates information, organized by user, to determine a
user's location. If properly handled, such location information can
be very useful. One example, dispatching employees to make sales
calls or sevice calls, was mentioned above. The goal of the present
invention is to allow users to collect and evaluate information
from multiple sources, and this make proper use of all available
location information.
[0009] Without such a method or system, positioning technologies
cannot properly handle multiple location sources for a single user,
or a single location source shared by multiple users. Without such
a method or system, users would be left with the above-mentioned
problem of location information from one source being inconsistent
with information from another source.
[0010] The solution is to make proper use of all available location
information, by first collecting and then evaluating information
from multiple sources. Information from some sources generally
would be more reliable than others. For example, information from a
device that is not shared may be more reliable than information
from a device that is shared by more than one user. Information
from a device that recently changed position may be more reliable
than information from a device that has not recently changed
position.
[0011] Instead of merely locating a mobile device, the present
invention locates people, i.e. users who may have more than one
mobile device, and perhaps computerized calendars that indicate a
person's expected location. The electronic sources of location data
(hereinafter referred to as "location sources") for the present
invention include mobile electronic devices such as mobile
telephones, personal computing devices. Location sources also
include computer-based models, schedules or calendars that give a
person's expected location depending on the date and time. These
models, schedules or calendars may be stored on personal digital
assistants, desk-top computers, or servers, for example.
[0012] After location information is acquired from location
sources, a user who is tracking the locations of other users might
evaluate the collected location information himself or herself, or
evaluation could be automated. In a fully automated system, a
computer would perform ranking or filtering operations on the data
before providing the information to the user.
[0013] One aspect of the present invention is a method for
aggregation information to determine a user's location. Another
aspect of the present invention is a system for executing the
method of the present invention. A third aspect of the present
invention is as a set of instructions on a computer-usable medium,
or resident in a computer system, for executing the method of the
present invention.
[0014] This summary is not intended as a comprehensive description
of the claimed subject matter but, rather, is intended to provide a
brief overview of some of the functionality associated therewith.
Other systems, methods, functionality, features and advantages of
the invention will be or will become apparent to one with skill in
the art upon examination of the following figures and detailed
description.
BRIEF DESCRIPTION OF THE FIGURES
[0015] A better understanding of the present invention can be
obtained when the following detailed description is considered in
conjunction with the following drawings. The use of the same
reference symbols in different drawings indicates similar or
identical items.
[0016] FIG. 1 is an exemplary block diagram of location data being
delivered over a computer network with an information handling
system, according to the teachings of the present invention;
[0017] FIG. 2 is a high-level block diagram illustrating selected
components that may be included in the exemplary information
handling system of FIG. 1;
[0018] FIG. 3 is a high-level block diagram illustrating an example
of a system for acquiring, aggregating, and evaluating location
information, according to the teachings of the present
invention;
[0019] FIG. 4 is a high-level based block diagram illustrating an
example of a system for acquiring and aggregating location
information, according to the teachings of the present
invention;
[0020] FIG. 5 is a block diagram illustrating in greater detail
selected components that may be included in the exemplary system of
FIG. 4.
[0021] FIG. 6 is a flow chart illustrating one type of process for
acquiring and aggregating location information, as implemented in
an exemplary embodiment;
[0022] FIG. 7 is a flow chart illustrating another process, related
to the type shown in FIG. 6, for acquiring and aggregating location
information, as implemented in an exemplary embodiment.
[0023] FIG. 8 is a sample Location XML document, according to the
teachings of the present invention, showing location data from a
two-way pager with GPS capability, as viewed with a browser.
DETAILED DESCRIPTION OF THE FIGURES
Overview
[0024] The present invention is a system and method that acquires
and aggregates location information. A user might evaluate the
collected location information himself or herself, or evaluation
could be automated. The present invention could be useful in any
situation involving location information from multiple sources. One
example, a system using collected location information for
dispatching employees to make sales calls or service calls, is
mentioned above. Another example would be a system to alert a first
user that a second user of particular interest has arrived at a
meeting site. Another example would be a system interacting via the
World Wide Web with a user's hand-held computer, his computer-based
calendar, his GPS unit, and a map service, to provide appropriate
driving directions to his next meeting site. Another example would
be a system interacting via the World Wide Web with a user's cell
phone, and her computer-based calendar or to-do list, alerting a
mobile user when she approaches a site where some business needs to
be transacted. In these examples, information output could be
audible or visible, by text or graphics.
[0025] In these examples, note that a user would be provided with
useful information keyed to a user's actual location, and the user
would not need to make a query. Also note the importance of using
all available location information, from multiple sources,
organized by user.
[0026] The following are definitions of terms used in the
description of the present invention and in the claims.
"Computer-usable medium" means any signal or transmission facility
for communication with computers, and any kind of computer memory,
such as floppy disks, hard disks, Random Access Memory (RAM), Read
Only Memory (ROM), CD-ROM, flash ROM, non-volatile ROM, and
non-volatile memory. "Location data" or "location information"
means latitude and longitude, or any other descriptions of location
"Location sources" or "Location sources" means any electronic
source of location data. including mobile electronic devices such
as mobile telephones, personal digital assistants, pagers, Global
Positioning System (GPS) devices, servers associated with these
mobile electronic devices, and computer-based models, schedules or
calendars that give a person's expected location depending on the
date and time. "Users" or "user" means any person utilizing
location sources being tracked by the method or system of the
present invention and any person tracking the locations other
users.
System and Method
[0027] The present invention is not limited as to the type of
computer on which it runs. Referring now to FIG. 1, an exemplary
block diagram shows location data being delivered over a computer
network with an information handling system, according to the
teachings of the present invention. At the left side of FIG. 1,
location information is acquired from location sources device 101,
server 111, device 102, device 103, and device 104. Location data
is delivered over a computer network 94 to information handling
system 10. Within information handling system 10, location
aggregator 20 acquires location data regarding a user, or more than
one user, and creates collections of said location data regarding a
user, or more than one user, organized by user. In this example,
evaluation of the collected location information is automated. A
logic component, location logician 30, performs evaluation
(ranking, filtering, or consolidating operations) on the data
before providing the information to a user through a subscriber
application 40.
[0028] Referring now to FIG. 2, a high-level diagrams illustrates
selected components that may be included in the exemplary
information handling system 10 of FIG. 1. Information handling
system 10 is controlled primarily by computer readable
instructions, which may be in the form of software, wherever, or by
whatever means such software is stored or accessed. Such software
may be executed within the processor, also known as the Central
Processing Unit (CPU) 50 to cause information handling system 10 to
do work CPU 50 typically is a microprocessor of the kind available
from Intel Corporation or Advanced Micro Devices, Inc.
[0029] Memory devices coupled to system bus 5 include Random Access
Memory (RAM) 56, Read Only Memory (ROM) 58, and non-volatile memory
60. Such memories include circuitry that allows information to be
stored and retrieved. ROMs contain stored data that cannot be
modified. Data stored in RAM can be changed by CPU 50 or other
hardware devices. Non-volatile memory is memory that does not lose
data when power is removed from it. Non-volatile memories include
ROM, EPROM, flash memory, or battery-pack CMOS RAM. As shown in
FIG. 2 such battery-pack CMOS RAM may be used to store
configuration information. An expansion card or board is a circuit
board that adds functions or resources to the computer. Typically
expansion cards add memory, disk-drive controllers 66, video
support, parallel and serial ports, and internal modems. For
laptop, palm top, and other portable computers, expansion cards
usually take the form of PC cards, which are credit card-sized
devices designed to plug into a slot in the side or back of a
computer. Thus, empty slots 68 may be used to receive various types
of expansion cards or PC cards. Disk controller 66 and diskette
controller 70 both include special purpose integrated circuits and
associated circuitry that direct and control reading from and
writing to hard disk drive 72, and a floppy disk or diskette 74,
respectively. Such disk controllers handle tasks such as
positioning a read/write head. A single disk controller may be able
to control more than one disk drive. CD-ROM controller 76 may be
included in information handling system 10 for reading data from
CD-ROM 78 (compact disk read only memory). Such CD-ROMs use laser
optics rather than magnetic means for reading data.
[0030] Communication between information handling system 10 and
other information handling systems may be facilitated by serial
controller 88 and network adapter 90, both of which are coupled to
system bus 5. Serial controller 88 is used to transmit information
between computers, or between a computer and a peripheral devices,
one bit at a time over a single line. As illustrated, such a serial
interface may be used to communicate with modem 92. A modem is a
communicator device that enables a computer to transmit information
over a standard telephone line. Modems convert digital computer
signals to analog signals suitable for communications over
telephone lines. Modem 92 or network adapter 90 may provide a
connection to sources of software and information, such as a
server, an electronic bulletin board, the Internet or World Wide
Web. Network adapter 90 is a communication device that may be used
to connect information handling system 10 to a network 94. Network
94 may provide computer users with means of communicating and
transferring software and information electronically. Additionally,
network 94 may provide distributed processing, which involves
several computers in the sharing of workloads or cooperative
efforts in performing task.
[0031] Keyboard mouse controller 80 is provided in information
handling system 10 for interfacing with keyboard 82 and pointing
device 84, which may be implemented using a track ball, a joy
stick, touch sensitive tablet or screen, or as illustrated, a
mouse. The pointing device 84 may be used to move a pointer or
cursor visible on display 96. Another example of an input device
would be a pointer or cursor visible on display 96. Another example
of an input device would be a microphone for audio input. It should
be noted and recognized by those persons of ordinary skill in the
art that display 96, keyboard 82, and pointing device 84 may each
be implemented using any one of several known off-the-shelf
components.
[0032] Display 96, which is controlled by display controller 98, is
used to display visual output generated by information handling
system 10. Display 96 includes a display screen which may be
implemented using a cathode ray tube (CRT) a liquid crystal display
(LCD) an electrode luminescent panel or the like. Display
controller 98 includes electronic components required to generate a
video signal that is sent to display 96. Printer 100 may be copied
to information handling system 10 via parallel controller 102.
Parallel controller 102 is used to send multiple data and control
bits simultaneously over wires connected between system 5 and
another parallel communication device, such as printer 100. Another
example of an output device would be a speaker for audio
output.
[0033] CPU 50 fetches, decodes, and executes instructions, and
transfers information to and from other resources via the
computer's main data-transfer path, system bus 5. Such a bus
connects the components in an information handling system 10 and
defines the medium for data exchange. System 5 connects together
and allows for the exchange of data between memory units 56, 58 and
60. CPU 50, and other devices as shown in FIG. 2
[0034] Referring now to FIG. 3, a diagram is shown illustrating an
example of a system for acquiring, aggregating, and evaluating
location information, according to the teachings of the present
invention. In the invention as currently implemented, the Java
programming language was used, but other languages could be used.
At the left side of FIG. 3, location information is acquired from a
group of location sources 300, including location source 101,
location source 102, and location source 103, in this example.
[0035] Output from location sources 300 could be in hypertext
markup language (HTML), extensible markup language (XML), or some
other language. In the invention as currently implemented, location
information is acquired through a set of adapter servlets 310,
including adapter 301 and adapter 302, in this example. These
adapters convert location data from various location sources to a
single format. In the invention as currently implemented, the
single format was implemented in XML, named "Location XML" or
"LocXML." Location data also could be acquired directly, as form
location source 103 in this example, Further description of
adapters is given below, in connection with FIG. 4.
[0036] Location aggregator 20 acquires location data regarding a
user, or more than one user, and creates collections of said
location data regarding a user, or more than one user, organized by
user. Collections of location data, shown as aggregated LocXML
information 321, are sent to logician facade 320, which
communicates with logic descriptions 330, logic bean factory 340,
and logic implementation 350. These are described in more details
below. These function to perform evaluation (ranking, filtering, or
consolidating operations) on the data before providing the
information to a user, by publishing new location list 322 to
subscriber application 40. In another embodiment, some ranking or
filtering could be performed by the location aggregator 20.
[0037] Regarding ranking, filtering, or consolidating operations,
different kinds of logic functions could be chosen by a user and
implemented as follows. Any logic function or process that is used
for ranking, filtering, or consolidating location data is called a
"logician" To "invoke" or "implement" a logician is to employ the
logician for ranking, filtering, or consolidating certain location
data. As a result of the API call GetLogicianTypes ( ) 331, logic
descriptions 330 returns logician types 332. This represents
choices being presented to a user. As a result of the API call
GetLogician (logician) 341, logic bean factory 340 returns logician
342. This represents a user choosing a kind of logic function to
implement. User preferences regarding logic functions could be
stored in and retrieved from subscriber preferences database 390.
As a result of API call logician invoke (LocationList) 351, logic
implementation 350 returns newLocationList 352. This represents a
chosen kind of logic function being implemented to rank, filter, or
consolidate location data. (Logic implementation 350 corresponds
with location logician 30 shown in the simplified diagram in FIG.
1.) By publishing new location list 322 to subscriber application
40, the system provides a user with location data that is ranked,
filtered, or consolidated.
[0038] The system may rank items in a collection of location
information, according to expected utility. A user who is tracking
the locations of another user may be provided with location data
such that a higher ranking is given to data from location sources
that indicate more recent movement. This is an example of ranking
data according to which location source moved more recently, and
thus generated the most recent location update. In the invention as
currently implemented, each Location XML entry has a time stamp,
and collections of location data are sorted by time stamp. In
another example of ranking, a user who is tracking the locations of
another user may be provided with location data such that a higher
ranking is given to data from location sources that are expected to
be more accurate than the other location sources. Another option
would give a higher ranking to data from location sources that are
capable of more precise measurement.
[0039] To give an example of filtering data sudden small changes in
reported location could be caused by random variation in location
measurement, not actual movement. This is a type of noise that can
be filtered out, by setting limits on which pieces of new location
data are added to a collection of current location data. Thus the
system may filter data to remove misleading data.
[0040] The present invention would be capable of consolidating
location data found in a collection of location data, to determine
the most likely location of a user. For example, a user may be
provided with the most likely location of another user who is being
tracked, as a result of the system determining a consensus
location, based on data from more than one location source. A
consensus location, indicated by data from any one location source
taken alone.
[0041] Through feedback from users regarding actual location, and
conventional artificial intelligence algorithms, the system could
learn to improve its performance. The system could learn which
location source, or combination of location sources, are most
useful.
[0042] To continue with an example given above, an employer may use
location information from employees mobile electronic devices to
determine the employees location. This system would help the
employer make good decisions about dispatching employees to make
sales calls or service calls. The present invention would make such
a system more useful. An employer could use the present invention
as follows. Referring again to FIG. 3, logic descriptions 330
returns logician types 332. This represents choices being presented
to a user, such as an employer. The choices may be presented in a
menu, including "most-recently-moved," "most precise," and other
options. Logic data factory 340 returns logician 342. This
represents a user choosing a kind of logic function to implement.
An employer may choose "most-recently-moved." For this logician the
rule could be stated this way: "rank data according to which
location source moved more recently, and thus generated the most
recent location update." This is an example of ranking items in a
collection of location information, according to expected
utility.
[0043] To continue with an example given above, a husband and wife
may share a tracking device that is embedded in the car. In
addition, the husband may have a two-way pager with GPS capability.
At mid-day, perhaps the shared car has not moved for a few hours,
but the husband with his two-way pager has been moving frequently.
The husband may have moved around the employer's plant, and then
traveled in an employer-owned vehicle to call on a customer. The
employer may track the husband. Logic implementation 350 returns
newLocationList 352. This represents a "most-recently-moved" logic
function being implemented to rank location data. By publishing new
location list 322 to subscriber application 40, the system provides
the employer with location data that is ranked. Location data from
the husband's two-way pager would be at the top of the list, ranked
above location data from the shared car that has not moved for a
few hours. The list may appear as a list of entries like the
example in FIG. 8 below. Subscriber application 40 could help the
employer to interpret the location data by displaying a map, for
example. Subscriber application 40 could display a simplified
version of the location data, to suit a user's preferences. The
following table is a simplified example of a collection of location
data regarding a user, such as the husband in the preceding
example. TABLE-US-00001 Location data for husband Rank Location
Source Location 1. Pager Latitude = N374820 Longitude = W1222738 2.
Car Latitude = N374822 Longitude = W1222740
Such a collection could include entries from additional location
sources such as a calendar or cell phone.
[0044] FIG. 4 is a high-level block diagram illustrating an example
of a system for acquiring and aggregating location information
according to the teachings of the present invention. In this
example, location aggregator 20 polls location sources GPS server
411, a maintain a carrier synchronized to its secondary fundamental
voltage at a desired angle relative to such a voltage, and a method
of determining the difference between the primary voltage and each
cell's secondary voltage. Any methods of calculation now or
hereafter known may be used.
[0045] In the methods described herein, although a master clock may
be used to determine an initial offset value, the master clock need
not be used when performing synchronization, as the system has
determined a set phase relationship for each carrier signal to the
fundamental. Thus, a synchronizing clock signal is not required
after the initial offset is determined. TABLE-US-00002 <!--DTD
for location information from mobile devices--> <!ELEMENT
LocationInformation (MobileDevice+)> <!ELEMENT MobileDevice
(Geographic+,TowerID?)> <!ATTLIST MobileDevice TrackID CDATA
#REQUIRED> <!ATTLIST MobileDevice RequestTime CDATA
#REQUIRED> <!ATTLIST MobileDevice ErrorCode CDATA
#REQUIRED> <!ELEMENT Geographic (GeodeticDatum, HeightDatum,
Region)> <!ATTLIST Geographic Velocity CDATA #IMPLIED>
<!ATTLIST Geographic PositionTime CDATA #REQUIRED>
<!ELEMENT GeodeticDatum (WGS-84 | BESSEL-1841)> <!ELEMENT
WGS-84 (LatLong | UTM)> <!ELEMENT LatLong EMPTY>
<!ATTLIST LatLong PositionFormat (IDMS0 | IDMS3) #REQUIRED>
<!ATTLIST LatLong Latitude CDATA #REQUIRED> <!ATTLIST
LatLong Longitude CDATA #REQUIRED> <!ELEMENT UTM EMPTY>
<!ATTLIST UTM Positionformat (2 | 4) #REQUIRED> <!ATTLIST
UTM Easting CDATA #REQUIRED> <!ATTLIST UTM Northing CDATA
#REQUIRED> <!ATTLIST UTM Zone CDATA #REQUIRED>
<!ATTLIST UTM ZoneDesignator CDATA #REQUIRED> <!ELEMENT
BESSEL-1841 (RTS-90)> <!ELEMENT RTS-90 EMPTY> <!ATTLIST
RTS-90 PositionFormat (IDMS0 | IDMS3) #REQUIRED> <!ATTLIST
RTS-90 Latitude CDATA #REQUIRED> <!ATTLIST RTS-90 Longitude
CDATA #REQUIRED> <!ELEMENT HeightDatum EMPTY> <!ATTLIST
HeightDatum HeightFormat (meters | yards) #REQUIRED>
<!ATTLIST HeightDatum HeightValue CDATA #REQUIRED>
<!ELEMENT Region EMPTY> <!ATTLIST Region RadiusFormat
(meters | yards) #REQUIRLD> <!ATTLIST Region InnerRadius
CDATA "0"> <!ATTLIST Region OuterRadius CDATA "0">
<!ATTLIST Region StartAngle CDATA "0"> <!ATTLIST Region
StopAngle CDATA "360"> <!ATTLIST Region LevelOfConfidence
CDATA "100"> <!ELEMENT TowerID EMPTY> <!ATTLIST TowerID
PositionTime CDATA #REQUIRED> <!ATTLIST TowerID Name CDATA
#REQUIRED> <!ATTLIST TowerID Type CDATA #REQUIRED>
[0046] The controller may then pass 418 the carrier offset angle to
the appropriate cell with a phase angle offset with respect to the
fundamental line voltage that results in the carrier signal being
interdigitated with other carrier signals delivered to other cells.
The carrier offset angle may be delivered to the cell as a
synchronization signal that represents the phase angle relationship
between the input voltage (i.e., the source or transformer primary
voltage) and the actual secondary voltage in each cell. The
synchronization signal may be part of the PWM carrier, or it may be
delivered as a separate signal. The cell then synchronizes 420 its
carrier signal to the secondary signal using the offset angle that
it receives from the controller.
[0047] FIG. 5 illustrates how multiple carrier signals 510, 520,
530, etc. for multiple cells may be interdigitated with each other
in a synchronized manner to a reference signal 550, as reflected to
the primary windings of the source transformer Each cell may have
its own reference signal, and the reference signals for each cell
will be similar but not necessarily the same. The carrier signal in
each cell will determine when a switching command occurs within
that cell. As shown in FIG. 5, since each carrier signal is
phase-shifted from the carrier signals from the other cells by a
predetermined amount (2.sub.0), the effect of the switching
commands for each cell as reflected to the primary of the
transformer will be spaced out over a period of time based on the
2.sub.0 value, or the spacing of the interdigitation. Thus, instead
of all cells effectively implementing the same switching operation
at the same time (which would cause a large harmonic disturbance),
the effect of the switching operations at the primary of the
transformer occur in rapid sequence based on the substantially even
offset of the carrier signals. In addition, since the effective
frequency of the carrier signals seen at the source transformer
primary is relatively high (such as on the order of about
f.sub.cN), the harmonics may be further smoothed, as the impedance
of the source transformer itself may filter our some or all of the
high-frequency harmonics.
[0048] In some embodiments, multiple drives may be connected to a
single transformer or a group of transformers sharing a common
primary voltage. In such a situation, multiple drives may have
their carrier signals interdigitated by adjusting the drive carrier
offset angle (2.sub.R) for each drive and setting each drive to the
same carrier frequency.
[0049] In the embodiments provided herein, the interdigitation of
the carrier signals may increase the frequency of the voltage
harmonics and reduce the peaks of the voltage harmonics, which in
turn may reduce current harmonics. For example, FIG. 6 illustrates
an exemplary trace of one phase of voltage 610 and current 620
delivered to a load from a drive having twenty-one regenerative
power cells using a source transformer rated for 7200 volts primary
and 600 volts secondary. In the data shown in FIG. 6, although the
source transformer had phase-shifted secondaries, carrier
de-synchronization (i.e., the shifting of the carrier signals by an
offset) was not performed, and both voltage and current harmonics
are obvious in the traces. FIGS. 7 and 8 show traces of current 720
and voltage 810 on the same circuit after the application of
carrier synchronization methods such as those described herein.
[0050] In some embodiments, interdigitation of the switching events
may occur using known methods other than adjustment of a carrier
signal. For example, if space vector modulation is used instead of
sine triangle methods as described herein, the method still may
include interdigitating the effective timing of switching events as
reflected to the primary.
[0051] Still other embodiments will become readily apparent to
those skilled in this art from reading the above-recited detailed
description and drawings of certain exemplary embodiments. It
should be understood that numerous variations, modifications, and
additional embodiments are possible, and accordingly, all such
variations, modifications, and embodiments are to be regarded as
being within the spirit and scope of this application
* * * * *