U.S. patent application number 13/039000 was filed with the patent office on 2011-06-23 for real-time location system using tag interrogator and embedded or fixed tag transmitters.
This patent application is currently assigned to Zebra Enterprise Solutions Corp.. Invention is credited to Walter S. Johnson, Santiago Romero.
Application Number | 20110148589 13/039000 |
Document ID | / |
Family ID | 39368702 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110148589 |
Kind Code |
A1 |
Johnson; Walter S. ; et
al. |
June 23, 2011 |
Real-Time Location System Using Tag Interrogator and Embedded or
Fixed Tag Transmitters
Abstract
A system tracks vehicles within a terminal and includes at least
one tag interrogator mounted on a vehicle to be identified and
tracked within the terminal. The tag interrogator is operative for
emitting a signal containing data identifying the vehicle to which
the tag interrogator is mounted. At least one tag transmitter is
fixed at a known location within the terminal where vehicles are to
be identified and receptive to a tag interrogator on the vehicle
when the vehicle passes within proximity to the fixed tag
transmitter for transmitting a wireless RF signal having data
identifying the tag transmitter and identifying the tag
interrogator as an identifier for the vehicle to which the tag
interrogator is mounted. At least one access point is positioned at
the terminal for receiving the RF signal from the tag transmitter
for subsequent processing to verify vehicle identity at the known
location.
Inventors: |
Johnson; Walter S.; (San
Jose, CA) ; Romero; Santiago; (Mount Airy,
MD) |
Assignee: |
Zebra Enterprise Solutions
Corp.
|
Family ID: |
39368702 |
Appl. No.: |
13/039000 |
Filed: |
March 2, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11938866 |
Nov 13, 2007 |
7916026 |
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13039000 |
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60865964 |
Nov 15, 2006 |
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Current U.S.
Class: |
340/10.1 |
Current CPC
Class: |
G01S 13/74 20130101;
G06Q 10/08 20130101; G06Q 10/087 20130101 |
Class at
Publication: |
340/10.1 |
International
Class: |
H04Q 5/22 20060101
H04Q005/22 |
Claims
1. A system for tracking vehicles within a terminal, comprising at
least one tag interrogator mounted on a vehicle to be identified
and tracked within the terminal and operative for emitting a signal
containing data identifying the vehicle to which the tag
interrogator is mounted; at least one tag transmitter fixed at a
known location within the terminal where vehicles are to be
identified and receptive to a tag interrogator on a vehicle when
the vehicle passes within proximity to the fixed tag transmitter
for transmitting a wireless RF signal having data identifying the
tag transmitter and identifying the tag interrogator as an
identifier for the vehicle to which the tag interrogator is
mounted; and at least one access point positioned at the terminal
for receiving the RF signal from the tag transmitter for subsequent
processing to verify vehicle identity at the known location.
Description
RELATED APPLICATION
[0001] This application is a continuation of application Ser. No.
11/938,866, filed Nov. 13, 2007 which is based on Provisional
Application No. 60/865,964 filed Nov. 15, 2006, each of which is
hereby incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] This invention relates to real-time location systems (RTLS)
using tag transmitters and tag interrogators.
BACKGROUND OF THE INVENTION
[0003] The modern marine terminal must efficiently process an
increasing number of containers in an area of limited space with
little, if any, land available for expansion. Capacity demands are
increasing rapidly with higher volumes of container traffic
worldwide and new, larger container ships coming on-line. Specific
containers should be located on demand among the thousands of
containers at any given time, but this can be difficult if there is
a lack of an accurate and real-time container identification and
tracking system of drayage tractors, switched tractors, wheeled
container chassis, top and side pick loaders, and gantry and quay
cranes. Locating a container can also be complicated by the number
of ways in which containers can be processed through a terminal.
For example, some containers arrive via a vessel or train and are
driven through a check-in gate by an outside truck. Once a
container enters the terminal, it can be parked on a chassis or
bombcart in a terminal, or removed from the chassis and placed on
top a stack of shipping containers. When a container is to be
retrieved, it must be located among the thousands of containers in
the terminal. These containers may be moved around the terminal by
outside drivers, or moved by marine terminal drivers, using a
client's tractor with terminal equipment.
[0004] Maintaining inventory and track of every container in the
terminal is difficult and the large number of containers and the
different ways in which the containers can be moved throughout the
terminal makes it difficult to locate a specific container when it
is needed. Also, the marine terminal often does not run smoothly
and this complicates the location system.
[0005] Different systems are used for processing containers through
a marine terminal, such as discharging a container from a vessel to
chassis. For example, containers may arrive in a marine terminal
via a vessel or rail. Other containers can be discharged from a
vessel to ground. When containers arrive at a marine terminal via a
vessel or train, they can be "discharged" or placed on a
bombcart/port trailer to be stacked, instead of parked on a
chassis. Other containers can be checked in at a gate. Instead of
arriving via a vessel or train, a container may arrive via a
central check-in gate. Drivers employed by customers of the marine
terminal arrive at the gate for check-in, where they pass through a
gate much like a highway toll plaza. At this gate, information is
collected about the container, after which the driver is instructed
either to park the chassis and container in a particular location
or to discharge the container to ground.
[0006] These different systems for processing containers make it
difficult to track the containers in a marine terminal. Tracking
container movement throughout the marine terminal is important
because searching for any misplaced containers requires time and
labor costs and adds to the shipping time of goods.
[0007] One prior art system uses brightly colored, highly
distinctive sticker magnets placed on each container. Terminal
employees walk around the terminal looking for these magnets and
noting their locations when they are found. This solution is
accurate, but the containers could be moved within the terminal
after the sticker magnets have been sighted, and the process of
searching for sticker magnets on containers is labor-intensive.
There is also a time-lag in obtaining data using this method.
[0008] Other prior art systems use wireless technology to track the
location of containers within a marine terminal. These systems
require some human intervention to locate items, and may have some
lag time for data collection. Although some of these described or
other prior art systems may provide for tracking parked containers
on a chassis (wheeled), it is even more difficult to track stacked
containers (grounded).
[0009] A system for tracking cargo containers contained within a
terminal such as a modern marine terminal that overcomes many of
the drawbacks noted above is disclosed in commonly assigned U.S.
Patent Publication No. 2006/0220851, filed Aug. 11, 2006 as U.S.
patent application Ser. No. 11/201,956, the disclosure which is
hereby incorporated by reference in its entirety. The system
includes a tag transmitter adapted to be positioned on container
handling equipment and operative for transmitting a wireless RF
signal based on an event affecting the location of a container
handled by the container handling equipment. A plurality of spaced
apart access points are positioned at known locations within the
terminal that receive the wireless RF signals from the tag
transmitter. A processor is operatively connected to the locating
access points for geolocating the tag transmitter and determining
the container location at the time the event occurs.
[0010] In another aspect, a sensor is adapted to be mounted on the
container handling equipment and operative with the tag transmitter
for sensing an event and transmitting data to the tag transmitter
for transmission of event data from the tag transmitter. The sensor
is operative for sensing the removal, placement or release of a
container, and the height of any gripper located on the container
handling equipment to indicate the height of a container when
stacked with other containers.
[0011] In some cases, it is necessary to verify the position of
mobile equipment such as shuttle trucks (STs) and utility tractor
rigs (UTRs) at specific points in the terminal. It is also
desirable to provide some type of permanent milepost indication at
the terminal as a crossing indication, or an X/Y location as a
grid-of-tags.
SUMMARY OF THE INVENTION
[0012] A system tracks vehicles within a terminal and includes at
least one tag interrogator mounted on a vehicle to be identified
and tracked within the terminal. The tag interrogator is operative
for emitting a signal containing data identifying the vehicle to
which the tag interrogator is mounted. At least one tag transmitter
is fixed at a known location within the terminal where vehicles are
to be identified and receptive to a. tag interrogator on the
vehicle when the vehicle passes within proximity to the fixed tag
transmitter for transmitting a wireless RF signal having data
identifying the tag transmitter and identifying the tag
interrogator as an identifier for the vehicle to which the tag
interrogator is mounted. At least one access point is positioned at
the terminal for receiving the RF signal from the tag transmitter
for subsequent processing to verify vehicle identity at the known
location.
[0013] The terminal can be a. cargo container terminal and the
vehicle could be container handling equipment that handles cargo
containers that are moved throughout the cargo container terminal.
A container crane can be positioned at the known location to which
the vehicle to be identified passes. This container crane can have
a plurality of vehicle lanes each having at least one tag
transmitter associated therewith for responding to any tag
interrogators on vehicles passing through a respective lane and
verifying identity of the specific vehicle at a specific lane of
the container crane.
[0014] The processor is operative with the at least one access
point for collecting data from the access point regarding the tag
interrogator and tag transmitter and providing a reference location
for current and alternate tracking solutions for the vehicle
throughout the terminal. The tag interrogator can transmit a
magnetic signal carrying identification data that activates the
fixed tag transmitter in proximity at the known location for
initiating transmission of the RF signal from the tag
transmitter.
[0015] In yet another aspect, the tag transmitter is formed as a
road marker fixed to the ground surface to which the tag
transmitter is associated. The road marker comprises a
substantially circular configured disk secured to the ground
surface and the tag transmitter is mounted within the disk or
secured to the underside of the disk. A protective housing can be
secured to the underside of the disk and carry the tag
transmitter.
[0016] In yet another aspect, a plurality of tag transmitters are
distributed throughout the terminal and form a grid pattern of tag
transmitters.
[0017] A method aspect is also set forth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Other objects, features and advantages of the present
invention will become apparent from the detailed description of the
invention which follows, when considered in light of the
accompanying drawings in which:
[0019] FIG. 1 is a fragmentary, environmental view of a real-time
location system for locating containers in a marine terminal.
[0020] FIG. 2 is a high level block diagram of one example of
circuit architecture that can be used for a locating access
point.
[0021] FIG. 3 is another high level block diagram of one example of
circuit architecture that can be used for a correlation-based, RF
signal location processor.
[0022] FIG. 4 is a high level flow chart illustrating the steps
used when a container is unloaded from a vessel to a chassis.
[0023] FIG. 5 is a high level flow chart illustrating the steps
when discharging a container from vessel to ground.
[0024] FIG. 6 is a high level flow chart of an example of
processing containers through a gate of the marine terminal.
[0025] FIG. 7 is an example of a computer window as a graphical
user interface for a container stacking console.
[0026] FIG. 8 is an example of a computer window as a graphical
user interface for a switcher user interface.
[0027] FIG. 9 is an environmental view of a top pick, drayage
tractor and chassis with the top pick unloading the container.
[0028] FIG. 10 is an environmental view showing stacked
containers.
[0029] FIG. 11 is an environmental view showing stacked containers
and a gap between containers for top pick spreaders.
[0030] FIG. 12 is an environmental view showing a top pick placing
a container on top of a stack.
[0031] FIG. 13 is an environmental view showing a top pick moving a
container and a vertical antenna positioned on the top pick.
[0032] FIG. 14 is a fragmentary plan view of a mounting plate for
three tags located on top of the top pick antenna mast.
[0033] FIGS. 15 and 16 are environmental views of a top pick and
its top pick spreader showing the antenna mast in FIG. 15.
[0034] FIG. 17 is a fragmentary front elevation view showing
different vehicle lanes at a quay crane or rail-mounted gantry
(RMG) crane and showing locations of different tags and tag
interrogators (port devices) in accordance with a non-limiting
example of the present invention.
[0035] FIG. 18 is a fragmentary plan view of a rail mounted gantry
crane and showing lane identifications for shuttle trucks in which
tags are placed in the pavement at lane locations for identifying
shuttle trucks in accordance with a non-limiting example of the
present invention.
[0036] FIG. 19 is a fragmentary, front elevation view of a shuttle
truck showing tag interrogators positioned on the shuttle truck in
accordance with a non-limiting example of the present
invention.
[0037] FIG. 20 is an environmental view in perspective showing the
general location where tag interrogators can be placed on shuttle
truck legs in accordance with a non-limiting example of the present
invention.
[0038] FIG. 21 is an environmental, front elevation view of a
utility tractor rig (UTR) on the land side rail-mounted gantry
(RMG) crane and showing lane positions for embedded tag
transmitters in accordance with a non-limiting example of the
present invention.
[0039] FIG. 22 is a plan view of a yard crane area showing the
position of location sensors as locating access points that receive
radio frequency transmissions from tags that have been actuated by
tag interrogators in accordance with a non-limiting example of the
present invention.
[0040] FIG. 23 is an enlarged environmental view of a top handler
vehicle showing the location of a tag interrogator in accordance
with a non-limiting example of the present invention.
[0041] FIG. 24 is a general perspective view of a tag interrogator
that can be used in accordance with a non-limiting example of the
present invention.
[0042] FIG. 25 is a drawing showing an example of the range in feet
of tag interrogators in accordance with a non-limiting example of
the present invention.
[0043] FIG. 26 is a fragmentary, side elevation view showing a tag
interrogator operative as a magnetic signal source positioned on a
vehicle and operative with a "buried". or embedded tag in
accordance with a non-limiting example of the present
invention.
[0044] FIG. 27 is a fragmentary side elevation view showing an
embedded tag in different implementations used for high and low
speed vehicle crossings in accordance with a non-limiting example
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0046] In accordance with a non-limiting example of the present
invention, different tag interrogators can be applied on shuttle
trucks and similar vehicles used in a marine or other terminal. Tag
transmitters are attached to the quay or similar cranes to indicate
lane positioning of the shuttle truck as a non-limiting example.
Tags can be embedded in the pavement, for example, at the shuttle
truck transfer area as a non-limiting example. The tag
communication link can be independent of a wireless local area
network (LAN) because it transmits to location centers on light
poles near the berth as a non-limiting example. The embedded tag
transmitter system can be used for other purposes.
[0047] There now follows a general description of a real-time
location system for tracking containers in a marine terminal
followed by a more detailed description of different embodiments of
the real-time location system using a tag interrogator and embedded
or fixed tag transmitters such as on quay or similar cranes or in
the pavement in accordance with non-limiting examples of the
present invention.
[0048] A real-time location system and method that can be modified
for use in the system and method of the present invention is
described in commonly assigned U.S. Pat. Nos. 6,657,586 and
7,212,563, the disclosures which are hereby incorporated by
reference in their entirety. Similar, commonly assigned patents
include U.S. Pat. Nos. 5,920,287; 5,995,046; 6,121,926; and
6,127,976, the disclosures which are hereby incorporated by
reference in their entirety.
[0049] As noted in the 1586 patent, GPS can be used with a tag
signal reader or locating access point for adding accuracy. Also, a
port device as a tag interrogator (either separate or part of a
locating access point) can include circuitry operative to generate
a rotating magnetic or similar electromagnetic or other field such
that the tag interrogator is operative as a proximity communication
device that can trigger a tag to transmit an alternate (blink)
pattern. The tag interrogator causes the tag to "blink" or
transmit, and can be termed such. Such an interrogator is described
in commonly assigned U.S. Pat. No. 6,812,839, the disclosure which
is incorporated by reference in its entirety.
[0050] When a tag transmitter passes through a tag interrogator
field, the tag can initiate a preprogrammed and typically faster
blink rate to allow more location points for tracking a tagged
asset, such as a vehicle hauling a container as it passes through a
critical threshold, for example, a shipping/receiving backdoor or
gate entry to a marine terminal. Such tags, tag interrogators, and
locating access points and associated systems are commonly sold
under the trade designation WhereTag, WherePort and WhereLan by
Wherenet USA headquartered in Santa Clara, Calif.
[0051] A system and method for tracking containers in a marine
terminal is first described relative to FIGS. 1-16, followed by a
more detailed explanation relative to FIGS. 17-27 of the system and
method for tracking vehicles in terminal applications in accordance
with a non-limiting example of the system and method of the present
invention in which tag interrogators are tracked and work in
association with embedded or fixed tag transmitters and provide
real-time location and tracking.
[0052] FIG. 1 is a fragmentary environmental view of a real-time
location system 20 for locating containers in a marine terminal and
showing various applications of this real-time location system 20
such as also described in the incorporated by reference U.S. Patent
Publication No. 2006/0020851. A computer server 22 is operative
with a terminal operating system (TOS) 24. The server 22 and
terminal operating system 24 provide a visibility software suite
and marine module with a bidirectional terminal operating system
interface that is operative with various locating access points 26.
The server 22 also provides processing for receiving data signals
from the locating access points 26, which had received wireless
signals from tags 28. Throughout this description, the tag is also
termed tag transmitter or tag transceiver and includes functions as
described for transmitting RF signals and receiving signals. The
server 22 in this example can be operative as a location processor
for determining which tagged signals are first-to-arrive signals
and conduct differentiation of first-to-arrive signals relative to
the location of locating access points as determined by any global
positioning system (if used) in order to locate a tag 28, such as
positioned on vehicle handling equipment.
[0053] As shown, a locating access point can be operative as an
access point 26 with WIFI 802.11b Standards and the tag 28 as a
location sensor can use ANSI 371.1 Standards that incorporates
communication standards for a 2.4 GHz air interface. The gate 34
could be operative with an OCR terminal 36. A tag 28 is positioned
at the gate to improve OCR transactions and track containers to
wheeled 38 and grounded 40 positions. The OCR terminal 36 includes
different OCR cameras 42. The tag placement options are shown as on
a draymen's truck 43, trailer chassis 44 or container 46. At the
grounded position 40, a port device 50 is shown positioned on the
illustrated crane 52. The tag updates of a wheeled container in the
wheeled position 78 could be operative such that no mobile
inventory vehicle, magnet or clock update is required. The server
22 and TOS 24 could also provide a user interface for a wheeled
location update as illustrated.
[0054] In a vessel position 54, a tag 28 could be located with an
OCR camera 42 for vessel unloading at a maritime crane 56. It
should be understood that the tags can be used to upload
maintenance and other information from the vehicle, such as hours
of operation and fuel levels.
[0055] A telemetry unit, such as a VCOM unit or other position
tracking interface unit (PTIU) 58, can transmit sensor data through
the tag 28 and can report to the real-time location system 20 when
a chassis/container is disconnected from a tractor, such as when
the driver parks the chassis/container or other similar events. The
PTIU 58 can report to the real-time location system 20 when a
chassis/container is disconnected from a tractor, such as when the
driver parks the chassis/container. The PTIU or other telemetry
unit can transmit data from different sensors on the tractor, for
example, a proximity sensor on the king pin, a pair of hydraulic
sensors on the fifth wheel, and a reverse sensor as non-limiting
example. These three sensors could indicate when a container is
engaged or disengaged. Other sensors could be monitored to
determine an operator ID, collisions, fuel levels, usage
statistics, and maintenance information that can be used to improve
operational efficiency.
[0056] In the different systems for processing containers through
the marine terminal, the real-time location system 10 tracks the
location of containers continuously, such that the containers can
be found more easily.
[0057] FIGS. 2 and 3 represent examples of the type of circuits
that can be used with modifications as suggested by those skilled
in the art for locating access point circuitry and location
processor circuitry as part of a server or separate unit to
determine any timing matters, set up a correlation algorithm
responsive to any timing matters, and determine which tag signals
are first-to-arrive signals and conduct differentiation of
first-to-arrive signals to locate a tag or other transmitter
generating a tag or comparable signal.
[0058] Referring now to FIGS. 2 and 3, a representative circuit and
algorithm as described in the above mentioned and incorporated by
reference patents are disclosed and set forth in the description
below to aid in understanding the type of access point and location
processor circuitry that can be used for determining which signals
are first-to-arrive signals and how a processor conducts
differentiation of the first-to-arrive signals to locate a tag
transmitter.
[0059] FIG. 2 diagrammatically illustrates one type of circuitry
configuration of a respective architecture, for "reading"
associated signals or a pulse (a "blink") used for location
determination signals, such as signals emitted from a tag
transmitter to a locating access point. An antenna 210 senses
appended transmission bursts or other signals from the object and
tag transmitter to be located. The antenna in this aspect of the
invention could be omnidirectional and circularly polarized, and
coupled to a power amplifier 212, whose output is filtered by a
bandpass filter 214. Naturally, dual, diversity antennae could be
used or a single antenna. Respective I and Q channels of a bandpass
filtered signal are processed in associated circuits corresponding
to that coupled downstream of filter 214. To simplify the drawing
only a single channel is shown.
[0060] A respective bandpass filtered I/Q channel is applied to a
first input 221 of a down-converting mixer 223. Mixer 223 has a
second input 225 coupled to receive the output of a phase-locked
local IF oscillator 227. IF oscillator 227 is driven by a highly
stable reference frequency signal (e.g., 175 MHz) coupled over a
(75 ohm) communication cable 231 from a control processor. The
reference frequency applied to phase-locked oscillator 227 is
coupled through an LC filter 233 and limited via limiter 235.
[0061] The IF output of mixer 223, which may be on the order of 70
MHz, is coupled to a controlled equalizer 236, the output of which
is applied through a controlled current amplifier 237 and
preferably applied to communication cable 231 through a
communication signal processor, which could be an associated
processor. The communication cable 231 also supplies DC power for
the various components of the access point by way of an HF choke
241 to a voltage regulator 242, which supplies the requisite DC
voltage for powering an oscillator, power amplifier and
analog-to-digital units of the receiver.
[0062] A 175 MHz reference frequency can be supplied by a
communications control processor to the phase locked local
oscillator 227 and its amplitude could imply the length of any
communication cable 231 (if used). This magnitude information can
be used as control inputs to equalizer 236 and current amplifier
237, so as to set gain and/or a desired value of equalization, that
may be required to accommodate any length of any communication
cables (if used). For this purpose, the magnitude of the reference
frequency may be detected by a simple diode detector 245 and
applied to respective inputs of a set of gain and equalization
comparators shown at 247. The outputs of comparators are quantized
to set the gain and/or equalization parameters.
[0063] It is possible that sometimes signals could be generated
through the clocks used with the global positioning system
receivers and/or other wireless signals. Such timing reference
signals can be used as suggested by known skilled in the art.
[0064] FIG. 4 diagrammatically illustrates the architecture of a
correlation-based, RF signal processor circuit as part of a
location processor to which the output of a respective RF/IF
conversion circuit of FIG. 3 can be coupled such as by wireless
communication (or wired in some instances) for processing the
output and determining location based on the GPS receiver location
information for various tag signal readers. The correlation-based
RF signal processor correlates spread spectrum signals detected by
an associated tag signal reader with successively delayed or offset
in time (by a fraction of a chip) spread spectrum reference signal
patterns, and determines which spread spectrum signal is the
first-to-arrive corresponding to a location pulse.
[0065] Because each access point can be expected to receive
multiple signals from the tag transmitter due to multipath effects
caused by the signal transmitted by the tag transmitter being
reflected off various objects/surfaces, the correlation scheme
ensures identification of the first observable transmission, which
is the only signal containing valid timing information from which a
true determination can be made of the distance.
[0066] For this purpose, as shown in FIG. 3, the RF processor
employs a front end, multi-channel digitizer 300, such as a
quadrature IF-baseband down-converter for each of an N number of
receivers. The quadrature baseband signals are digitized by
associated analog-to-digital converters (ADCs). Digitizing
(sampling) the outputs at baseband serves to minimize the sampling
rate required for an individual channel, while also allowing a
matched filter section 305, to which the respective channels
(reader outputs) of the digitizer 300 are coupled to be implemented
as a single, dedicated functionality ASIC, that is readily
cascadable with other identical components to maximize performance
and minimize cost.
[0067] This provides an advantage over bandpass filtering schemes,
which require either higher sampling rates or more expensive
analog-to-digital converters that are capable of directly sampling
very high IF frequencies and large bandwidths. Implementing a
bandpass filtering approach typically requires a second ASIC to
provide an interface between the analog-to-digital converters and
the correlators. In addition, baseband sampling requires only half
the sampling rate per channel of bandpass filtering schemes.
[0068] The matched filter section 305 may contain a plurality of
matched filter banks 307, each of which is comprised of a set of
parallel correlators, such as described in the above identified,
incorporated by reference '926 patent. A PN spreading code
generator could produce a PN spreading code (identical to that
produced by a PN spreading sequence generator of a tag
transmitter). The PN spreading code produced by PN code generator
is supplied to a first correlator unit and a series of delay units,
outputs of which are coupled to respective ones of the remaining
correlators. Each delay unit provides a delay equivalent to
one-half a chip. Further details of the parallel correlation are
found in the incorporated by reference 1926 patent.
[0069] As a non-limiting example, the matched filter correlators
may be sized and clocked to provide on the order of 4.times.106
correlations per epoch. By continuously correlating all possible
phases of the PN spreading code with an incoming signal, the
correlation processing architecture effectively functions as a
matched filter, continuously looking for a match between the
reference spreading code sequence and the contents of the incoming
signal. Each correlation output port 328 is compared with a
prescribed threshold that is adaptively established by a set of
"on-demand" or "as needed" digital processing units 340-1, 340-2, .
. . 340-K. One of the correlator outputs 328 has a summation value
exceeding the threshold in which the delayed version of the PN
spreading sequence is effectively aligned (to within half a chip
time) with the incoming signal.
[0070] This signal is applied to a switching matrix 330, which is
operative to couple a "snapshot" of the data on the selected
channel to a selected digital signal processing unit 340-1 of the
set of digital signal processing units 340. The units can "blink"
or transmit location pulses randomly, and can be statistically
quantified, and thus, the number of potential simultaneous signals
over a processor revisit time could determine the number of such
"on-demand" digital signal processors required.
[0071] A processor would scan the raw data supplied to the matched
filter and the initial time tag. The raw data is scanned at
fractions of a chip rate using a separate matched filter as a
co-processor to produce an auto-correlation in both the forward (in
time) and backwards (in time) directions around the initial
detection output for both the earliest (first observable path)
detection and other buried signals. The output of the digital
processor is the first path detection time, threshold information,
and the amount of energy in the signal produced at each receiver's
input, which is supplied to and processed by the
time-of-arrival-based multi-lateration processor section 400.
[0072] Processor section 400 could use a standard multi-lateration
algorithm that relies upon time-of-arrival inputs from at least
three readers to compute the location of the tag transmitter. The
algorithm may be one which uses a weighted average of the received
signals. In addition to using the first observable signals to
determine object location, the processor also can read any data
read out of a memory for the tag transmitter and superimposed on
the transmission. Object position and parameter data can be
downloaded to a database where object information is maintained.
Any data stored in a tag memory may be augmented by altimetry data
supplied from a relatively inexpensive, commercially available
altimeter circuit. Further details of such circuit are found in the
incorporated by reference '926 patent.
[0073] It is also possible to use an enhanced circuit as shown in
the incorporated by reference '926 patent to reduce multipath
effects, by using dual antennae and providing spatial
diversity-based mitigation of multipath signals. In such systems,
the antennas are spaced apart from one another by a distance that
is sufficient to minimize destructive multipath interference at
both antennas simultaneously, and also ensure that the antennas are
close enough to one another so as to not significantly affect the
calculation of the location of the object by a downstream
multi-lateration processor.
[0074] The multi-lateration algorithm executed by the location
processor could be modified to include a front end subroutine that
selects the earlier-to-arrive outputs of each of the detectors as
the value to be employed in a multi-lateration algorithm. A
plurality of auxiliary "phased array" signal processing paths can
be coupled to the antenna set (e.g., pair), in addition to any
paths containing directly connected receivers and their associated
first arrival detectors that feed the locator processor. Each
respective auxiliary phased array path is configured to sum the
energy received from the two antennas in a prescribed phase
relationship, with the energy sum being coupled to associated units
that feed a processor as a triangulation processor.
[0075] The purpose of a phased array modification is to address the
situation in a multipath environment where a relatively "early"
signal may be canceled by an equal and opposite signal arriving
from a different direction. It is also possible to take advantage
of an array factor of a plurality of antennas to provide a
reasonable probability of effectively ignoring the destructively
interfering energy. A phased array provides each site with the
ability to differentiate between received signals, by using the
"pattern" or spatial distribution of gain to receive one incoming
signal and ignore the other.
[0076] The multi-lateration algorithm executed by the location
processor could include a front end subroutine that selects the
earliest-to-arrive output of its input signal processing paths and
those from each of the signal processing paths as the value to be
employed in the multi-lateration algorithm (for that receiver
site). The number of elements and paths, and the gain and the phase
shift values (weighting coefficients) may vary depending upon the
application.
[0077] It is also possible to partition and distribute the
processing load by using a distributed data processing architecture
as described in the incorporated by reference '976 patent. This
architecture can be configured to distribute the workload over a
plurality of interconnected information handling and processing
subsystems. Distributing the processing load enables fault
tolerance through dynamic reallocation.
[0078] The front end processing subsystem can be partitioned into a
plurality of detection processors, so that data processing
operations are distributed among sets of processors. The
partitioned processors are coupled in turn through distributed
association processors to multiple location processors. For tag
detection capability, each reader could be equipped with a low cost
omnidirectional antenna, that provides hemispherical coverage
within the monitored environment.
[0079] A detection processor filters received energy to determine
the earliest time-of-arrival energy received for a transmission,
and thereby minimize multi-path effects on the eventually
determined location of a tag transmitter. The detection processor
demodulates and time stamps all received energy that is correlated
to known spreading codes of the transmission, so as to associate a
received location pulse with only one tag transmitter. It then
assembles this information into a message packet and transmits the
packet as a detection report over a communication framework to one
of the partitioned set of association processors, and then
de-allocates the detection report.
[0080] A detection processor to association control processor flow
control mechanism equitably distributes the computational load
among the available association processors, while assuring that all
receptions of a single location pulse transmission, whether they
come from one or multiple detection processors, are directed to the
same association processor.
[0081] FIG. 4 is an example of a high level flow chart illustrating
how the real-time location system 20 as described can be used when
a container is unloaded from a vessel to a chassis. Reference
numerals begin in the 500 series.
[0082] As shown in the flow chart in FIG. 4, a container is
discharged to the chassis via crane (block 500). A clerk could
verify the container number "suggested" by optical character
recognition (block 502), although OCR is not required or desired in
some instances. The real-time location system 20 identifies the
tractor based on its position (block 504). A driver can be
instructed where to park the trailer (block 506). The driver parks
the container and disconnects (block 508). The real-time location
system 20 reports the position of the container when it is parked
(block 510). When the container is needed, it is found wherever the
driver parked it (block 512).
[0083] FIG. 5 shows a flow chart used when discharging from vessel
to ground, in one non-limiting example. A container is discharged
to a bombcart as a non-limiting example via crane (block 520). A
clerk verifies the container number "suggested" by optical
character recognition (block 522), although OCR is not required or
desired in some instances. The real-time location system 20
identifies the tractor based on its position (block 524). A driver
brings the container to a top handler (block 526). The top handler
moves the container from the bombcart to the stack (block 528). The
real-time location system 20 reports the position of the container
when it is discharged (block 530). Another clerk could confirm
stacked location (block 532). When a container is required, it is
found where it was discharged to ground (block 534).
[0084] The real-time location system 20 for tracking containers in
a marine terminal as described can also be used when processing
containers through a gate of the terminal, which involves similar
issues as discharging containers from vessel to chassis and from
vessel to ground. Drivers entering through a gate can be instructed
to park a chassis/container or to discharge the container to
ground. A large number of tractors and chassis enter from the
outside and some drivers and equipment do not always belong to the
terminal and are not permanently tagged. As shown in the example
high level flow chart of FIG. 6, additional step(s) can be added
for check-in. A temporary tag can be affixed to a chassis or
container as it enters the gate.
[0085] As illustrated, a driver arrives at the gate (block 550) and
a clerk notes the container and other information (block 552). A
tag is affixed to a chassis or container (block 554) and the driver
takes receipt indicating the suggested parking location or ground
assignment (block 556). A determination is made whether it is
parked or grounded (block 558). If the determination is made to
park, the driver parks the container and disconnects (block 560).
The real-time location system 20 reports the position of the
container when it was parked (block 562). When a container is
required, it is found wherever the driver parked it (block 564). If
a decision at block 558 was made for a grounded container, a
determination is made whether the container went to the top handler
as instructed (block 566). If not, the driver parks the container
and disconnects (block 568) and the process continues such that the
real-time location system 20 reports the position of the container
when it was parked (block 562).
[0086] If the top handler was instructed at block 566, the driver
brings the trailer to a top handler queue (block 570). The top
handler moves the container from the trailer to stack (block 572).
The real-time location system reports the position of the container
when it was parked (block 574). The clerk confirms the stacked
location (block 576). When the container is required, it is found
where it was discharged to ground (block 578).
[0087] The infrastructure, tracking devices and software as
described can support the tracking of container handling equipment
(CHE) and third party truckers (draymen) via a gate 34 to enable an
automated hand-off of the container ID to a terminal operating
system (TOS) 24. The real-time location system 20 can support an
automated update of the ground position 40 of a container in the
terminal, whether it is delivered by a truck or UTR (utility
tractor rig) to system enabled Front End Loaders (FEL). A flow
process for a draymen for gate to ground could include a permanent
or temporary mount real-time location system tag 28 on the draymen
tractor or chassis. This tag 28 could be triggered by a port device
50 as the chassis passes through an optional optical character
recognition (OCR) portal 36, which could automatically associate
the tagged ID to an OCR record.
[0088] A tag interrogator 50 could be located in each gate lane of
the gate 34 for automatic tag/transaction association and could
assign an OCR portal transaction to the correct lane. A front-end
loader could have a tag interrogator 50 that forces the draymen or
chassis tag to transmit its ID and the associated container ID
could be automatically transferred to the Front End Loader. This
could be tracked until the container is grounded. Sensor
information collected by a Position Tracking Interface Unit (PTIU)
58 or similar telemetry unit could collect sensor information and
transmit it via the Front End Loader's tag in a manner described
before. Sensor information could be received and the X,Y position
for the Front End Loader tag could be determined upon container
disengage. At the marine terminal server 22, the location of the
sensor information could be translated to a bay, cell and tier
position and updated to the terminal operating system 24.
[0089] For a gate to wheels scenario, the real-time location system
20 could compare a park instruction with a park signature created
by a draymen visiting the marine terminal. For example, a permanent
or temporary tag could be located on the draymen's tractor or
chassis and the tag read by the tag interrogator 50 as the draymen
passes through an optional OCR portal 36, which automatically
associates the tag ID for an OCR record. A tag interrogator 50
could be located at each gate lane at the gate 34 for automatic
tag/transaction association and assigning the OCR portal
transaction to lanes. The processing for the container can be
learned by querying the Terminal Operating System 24, tracking the
container, and monitoring it to ensure a grounded instruction is
adhered. The draymen could leave the container in the chassis or
bear the chassis into the marine terminal. The tag's position is
automatically determined with no need for a mobile inventory
vehicle or magnet retrieval. A wheeled position is updated to the
Terminal Operating System.
[0090] The real-time location system 20 is also operative for a
vessel or rail-to-ground and supports an automated association of
the container ID at the vessel for tracking a container ID to a
wheeled or grounded position 38,40 in the yard of the marine
terminal. The container ID can be associated to the UTR in this
example. For example, a quay crane 52 OCR or rail OCR portal could
be used to automatically capture a container ID and the container
and UTR are automatically associated based on UTR sensor sweep and
location. A tag interrogator on a transtainer and a UTR tag
automatically transfer ownership of the container to the
transtainer. The transtainer is located and the container
disengaged to determine an X,Y position. Other sensors, for
example, operative with the PTIU 58 could be used to determine a Z
position, as explained in greater detail below. The transtainer
disengaged location can be translated to a bay, cell, tier
position, or other position for the container and updated to the
Terminal Operating System 24.
[0091] The system as described can also be used for vessel or
rail-to-wheels in which the quay crane OCR or rail OCR portal
automatically captures the container ID. The container and UTR are
automatically associated based on UTR sensor sweep and location.
The UTR's location can be recorded upon chassis disengage and the
UTR automatically shows is available for its next assignment. The
UTR's disengaged location can be translated to a row or slot
position for the container and updated to your TOS.
[0092] The Position Tracking Interface Unit (PTIU) 58 can be
located on UTR's, side handlers, top handlers, reach stackers,
straddle carriers, RTG's and other container handling equipment,
and can transmit equipment sensor data through the tags 28 into the
Real-Time Location System 20 for processing by the server 22.
Sensor transmissions can be simplified by providing a common
platform for the container handling equipment. The PTIU 58 can
monitor what equipment is moving, who was using the equipment (with
operator logon), what the equipment is doing, such as idling or
moving a container, and other diagnostic data, such as fuel level
while the equipment is in operation. The PTIU 58 can respond to
events allowing the real-time location system 20 to update what
that specific equipment did when the PTIU 58 sends data to a tag
28. For example, when the operator of a RTG moves the RTG spreader,
no events are sent to the real-time location system 20. When an
operator locks the spreader on a container, however, the PTIU 58
sends this event data to the real-time locating system 20 because
it affects the location of container inventory.
[0093] The PTIU 58 can monitor any required sensors and respond to
correct events that affect container inventory. For example, for a
top handler or RTG, the events of locking onto a container and
moving the container could be similar, although sensors sense this
as different. For a UTR, the monitored events could be the fifth
wheel being engaged/disengaged and the presence of a container. The
events and sensors used may be different depending on the container
handling equipment.
[0094] The server as a location processor can include appropriate
software to process data received from the PTIU 58, such as to
provide an open computer window corresponding to a signature
processing console for each type of container handling equipment
located in the marine terminal. A new position for a container can
be translated from an X,Y,Z position in the terminal to a row, bay,
cell and tier position and passed through the Terminal Operating
System 24. An example of an open computer screen window for a
container stacking console is shown in FIG. 7, showing a layout of
different container positions in the top portion of the window and
an isometric representation of stacked containers in the lower
portion, as selected and indicated by the dashed lines. Location
information can also be shared with UTR drivers or other operators
of container handling equipment and a user interface could be
leveraged with a switcher user interface as shown in FIG. 8.
[0095] As noted before, the real-time location system 20 as
developed in the system and method can identify ISO containers
arriving at the marine terminal with tag interrogators 50 as
described before, and locate these containers when they are stored
on flat trailers, e.g., chassis, in the main staging yard as
wheeled operations. The containers can arrive through a main gate
and be scanned by tag interrogators 50 as described above, or by
rail and loaded by transtainers, as also described above, or arrive
by ship and loaded by cranes onto a UTR-pull chassis in a similar
process to a rail process. These "wheeled" containers are parked in
the yard, for example, by the incoming drayage driver (draymen), or
by a longshoreman hosteller (UTR) driver. The real-time location
system 20 maintains a constantly updated ID and location record of
all wheeled containers located in the yard.
[0096] Most wheeled operations use a chassis that is tagged.
Containers arriving into the yard on non-owned chassis could be
off-loaded by a "top pick" (e.g., also referred to as a "top pick
spreader") loader and stacked on the "ground" so that the outside
draymen can take the chassis as it leaves. FIG. 9 shows a drayage
tractor 600 having a tag, and a marine terminal owned chassis 602
with a tag. The top pick is illustrated at 604 within a horizontal
top pick spreader 605 for grabbing containers and the locating
access point (LAP) is shown generally at 26. The antenna mast 606
supports the LAP. The antenna mast 606 and LAP could include a GPS
unit. The ID and location of each container in the "grounded stack"
to its exact position in X,Y,Z coordinates is preferred, especially
when there are many stacked containers as shown in FIG. 10, showing
full containers generally at 610 that are stacked "four high" and
empty containers generally at 612 that are stacked "five high."
[0097] The grounded containers normally, but not always, have their
positions marked on the pavement as shown by the position lines 620
of FIG. 11. In one non-limiting example, the containers are 8.5
feet wide, 8.5 to 9.5 feet high, and have 20-foot, 40-foot, 45-foot
and 48-foot lengths. Spacing between the stacks made by any top
pick loaders typically have a minimum of about 1.5 feet for
transtainers that have a greater spacing to accommodate the
rail-guided loader as generally shown by the spacing 622 between
the two stacks of containers. In one non-limiting example, stacks
can be five containers high for empty containers, which typically
are about 80% of outbound containers, because the U.S. does not
export many containers. Full containers can be stacked up to four
high and the stack depth can be variable. The 1.5 foot gap 622 is
usually left between the containers for top pick spreaders with
port devices on the ends of the spreader that must fit in the area
and not be damaged. The chalk outline 620 shows the marked outline
of the storage area for containers.
[0098] Load and unload operations can be performed quickly,
allowing container locations that are associated with loader
locations to be captured in less than two seconds to avoid errors
in one non-limiting example. As shown in FIG. 12, the highest fixed
point 630 on the top pick spreader is above the top of the third
level container, about 30 feet. Because much of the marine
terminals in the world are grounded for yard space and input/output
efficiency, the grounded operations are becoming increasingly
important.
[0099] Although it is possible to include tags on containers, the
location of the containers can be inferred from real-time
association with the container handling equipment, which places and
removes them from the grounded stack and carrier chassis. FIG. 13
shows an antenna 650 locating access point, 81/2 foot stacked
containers 652, an 18-foot vertical whip antenna on the top pick
spreader 654 with the point shown at 656 on the top pick spreader
for mounting the antenna, and 91/2 foot containers 660. The whip
antenna for a tag transmission could be formed instead as a mast,
which supports a set of tags as explained below. Port devices 50 as
interrogators can be positioned on each end of the top pick
spreader bar as indicated generally at 662 for scanning a tag
positioned on a carrier chassis.
[0100] It should be understood that sensors on the handler can
indicate the placement of a container, the release of a container,
and the height of a gripper when an action occurs (Z dimension
value). This information could be sent with telemetry data from a
PTIU 58 using the tag 28 and simultaneously associating the
container handling equipment location with the data for the
transaction. A tag interrogator 50 induces the blink from the
chassis tag and/or the drayage tractor tag to associate the
container ID with the data from the handler tag.
[0101] Non-marine terminal chassis can be pulled by non-tagged
drayage tractors and can be manually entered at the terminal from a
video photo of a painted-on container number taken during a
transaction. This photo could be automatically requested from the
container handling equipment, over the local area network that
forms part of the real-time location system 20, if no tag
interrogator 50 induced blinks with the correct port device ID were
detected during the chassis placement. Optical character
recognition (OCR) could be used, but may not be desirable because
gate operations using OCR have demonstrated only about a 954 scan
success rate. Also, the vibration of the handler could degrade the
OCR performance even more than stable gate scanners. A two-second
association window created by a handler quick movement could cause
further degradation of OCR performance.
[0102] Because the handler moves quickly, the tag on the handler
could include a set of tags to ensure instantaneous location
accuracy. For example, three tags 28 as RF emitters or transmitters
could be simultaneously triggered by a telemetry unit from
recognized handler transactions. These tags could be set for a
minimum trigger delay of about 600 milliseconds with standard
multi-tag scan dither on the trigger. Each tag could produce four
sub-blinks with a normal 125 millisecond dithered spacing, creating
a maximum time diversity within the short burst window. Three,
one-quarter wavelength, tags 28a, 28b, 28c could be mounted near
the corners of a triangular mounting plate 670 forming a
counterpoise as shown schematically in FIG. 14. This plate 670
provides a ground plane and prevents reflections from containers
below. The plate 670 is mounted on the mast 654 in one non-limiting
example. The tags are typically spaced about 1/4 wavelength. This
type of configuration could provide spatial diversity with a
minimized radio frequency radiation below the antenna radiator
horizon. This configuration could also minimize some multi-path
from containers and other metal objects below the emission point
height. The three RF transmitters can provide some filtering
also.
[0103] Because the location of the handler must be as accurate as
possible, the typical RF emission from the handler tag should be
line-of-sight in a preferred embodiment to the existing
infrastructure of the real-time location system 20. This is
accomplished using the separate antenna mast 654 on the handler to
rise above the top plane of the stacked containers. An existing
18-foot fibreglass antenna mast as used for vertical diversity on
yard light poles in the marine terminal could be used. The
triangular mounting plate 670 supporting the tags at the top and a
new mount for attachment to the highest fixed location on the top
pick spreader. The transtainers are high and the mast should clear
the surrounding structure of the loader. Some mechanical
flexibility could be provided on the top pick spreader for overhead
obstacles, such as maintenance garage doors and overhead utilities
and conveyors. A GPS sensor 670 could also be located as mast 654
to provide additional location ability and redundancy overlay. When
the GPS is blocked, the RTLS 20 could be used, or both GPS and RTLS
20 used. If the RTLS infrastructure is blocked, the GPS could
provide location.
[0104] FIGS. 15 and 16 show two views of a top pick spreader 605
having an 18-foot antenna mast 654 with a bar 680 for an antenna
mount, and tag interrogator 50 mounting points 682 (FIG. 16). The
tag interrogator 50 should be mounted at both ends of the top pick
spreader 605 at its gripper 605a, 605b on either end because
orientation to the tagged end of a container on a chassis is
unknown. The port devices 50 should be mounted under a spreader and
plate to prevent damage from adjacent containers during placement
and removal operations from the stack. Electrical connection to a
port device antenna should be flexible enough to accommodate
20-foot to 45-foot container width handling.
[0105] The location accuracy in a grounded stack should typically
be about +/-10 feet (for 20-foot containers) for container length,
and about 41-4 feet for container width. The Z dimension in the
stack is typically up to about five containers high. Occasionally,
containers will be temporarily grounded in areas other than the
marked, grounded stacks. These containers should be identified as
not in a stack, but actual location indication could be zone only.
Tag interrogators 50 can be used to associate containers on marine
terminal chassis and/or with tagged drayage tractors with loaders.
Association with containers on chassis, pulled by untagged draymen,
is a challenge as previously described. This could result from the
structure of the top pick and the combination of the tractor,
container and chassis.
[0106] In one non-limiting example, containers arriving on tagged
marine terminal chassis and/or pulled by tagged drayman are
tracked, and untagged transactions by OCR or video camera are not
required.
[0107] A PTIU 58 or similar module can be connected to top pick
sensors for (a) container pick (removal); (b) container release
(placement); and (c) height of operation. A special tag could
include: (a) data input and blink trigger; and (b) 50 ohm RF output
connector.
[0108] The RF antenna mast with mounting plate 670 used on the top
pick could include the three element radiator formed by three tags
28a, 28b, 28c with sufficient separation for: (i) minimized
coupling and pattern distortion; (ii) adequate spatial diversity;
and (iii) minimum footprint to the top mount on the antenna mast.
This RF antenna could also include an upward hemispherical pattern
with minimized radiation below the horizon of the counterpoinse and
a mast long enough for a two-foot rise above the plane of highest
container stack. Special tag interrogators 50 can be used with top
pick, and include different circuits and structural functions, for
example, (a) pot and shock mount electronics; (b) a separate
antenna; (c) a flexible connection cable to the ends of the
spreader; (d) a weather shield; (e) damage protection; and (f)
verify port device coverage in the environment.
[0109] Both magnetic compass and inertial navigation techniques can
be used for optimization of loader position information.
Application specific location algorithms can be used for: (a) X,Y,Z
location of all containers in the grounded stack and zone location
when not in stack; (b) discerned placement and removal operations
from the stack; (c) associated tags on the chassis and/or drayage
tractor, and therefore, a container ID with containers placed or
removed by top pick; and (d) the associated three tags in a tag
set, which are tied to each top pick event for improved location
accuracy, allowing blinks to be sent in less than a 1.5 second
window. Application software can be used for location of all
containers in the grounded stack and stored in the asset manager,
and an isometric display of container in exact current form stack
from planar map zoom.
[0110] Reference is now made to FIGS. 17-27 in which non-limiting
examples as shown for the system and method of identifying the
location of vehicles such as at choke points in the marine or other
terminal. In accordance with a non-limiting example of the present
invention, the position of mobile equipment such as shuttle trucks
(STs) and utility tractor rigs (UTRs), as non-limiting examples,
can be verified at specific choke points at the terminal, for
example, a marine terminal as described above. "Port devices" as
tag interrogators are placed on shuttle trucks and similar vehicles
and each have an ID for identifying the interrogator. For example,
in one non-limiting example, four tag interrogators are positioned
per shuttle truck for a total of 80 tag interrogators on a 20-unit
shuttle truck fleet used in a marine terminal. Two tag
interrogators could be mounted near the bottom of the shuttle truck
and two tag interrogators could be mounted near the top of the
shuttle truck in a non-limiting example, which would give an
adjustable radius of about 1 to 20 feet from the shuttle truck.
[0111] Referring now to FIG. 17, a ship-to-shore (STS) container
crane, also known as a quay crane (QC) 700 is illustrated and
typically positioned parallel to a band of water and includes a
waterside and landside. The crane 700 includes crane legs 702, a
sill beam 704 at the top and a waterside and landside as described.
Four shuttle truck lanes 706 are illustrated with respective
shuttle trucks 708 positioned in each lane. Respective safety lanes
can be formed for ensuring proper guidance of shuttle trucks and
movement. A container 710 is illustrated in lanes 2 and 4 and could
include any necessary identifier or tag. Tags are operative as tag
transmitters 712 and attached to the quay crane 700, for example,
on its sill beam 704 and hung from support pipe 714 the lane
positions where the shuttle truck 708 passes under the quay crane
700. For example, there could be four shuttle truck lanes 706 as
illustrated for a quay crane and two crane ends, and a yard having
six quay cranes, resulting in a need for 48 tags 712. Some of these
tags could be embedded in pavement at the quay crane transfer area,
for example, at the waterside end. The tag communications link is
independent of any wireless local area network. For example, the
link could transmit to two location sensors as access points that
are mounted on light poles near the crane berth as a non-limiting
example.
[0112] As noted before, four tags 712 are supported by the sill
beam of the quay crane 700 at each shuttle truck lane and at each
end of the respective lane for a total of eight suspended tags for
this quay crane. Four tags are illustrated hanging from the sill
beam in FIG. 17, while the four tags that are not shown are
positioned at the other end of the quay crane. A tag interrogator
716 is placed on top of each shuttle truck 708 as illustrated and
activates the respective tag 712 in the respective lane. The local
sensor as an access point 720, such as on a light pole, receives
the lane ID and shuttle truck ID based on the tag interrogator on
the shuttle truck and the tag transmission from the tag. A computer
as part of a location processor 721 can relay this information to
provide a reference location for current and alternate tracking
solutions.
[0113] A fragmentary plan view of a rail-mounted gantry (RMG) crane
730 is shown in FIG. 18 with five lanes as illustrated. The RMG
crane 730 is similar to the quay crane of FIG. 12 and rail-mounted
for shuttle truck 708 movement and handling. Tags 712 placed in the
pavement at an. RMG lane, as illustrated by the round dots,
corresponding to tag locations. Six tags are embedded such that
each lane has a tag positioned on either side of the respective
lane as illustrated. The tag transmissions from tags 712 in the
pavement and the RFID provide verification of a shuttle truck lane,
for example, at the waterside end of this rail-mounted gantry
crane. Two or more tag interrogators are mounted on the shuttle
truck to activate the tag in the pavement irrespective of the
shuttle truck orientation. The tag ID and shuttle truck ID as
relayed by means of the tag interrogator can be transmitted to a
local area network via location access point such as located on a
light pole or other elevated surface. Two tags can be activated per
shuttle truck entry into the crane. A unique lane could be
identified by looking at the combination of tag TD's. For example,
if transmissions from tags 1 and 2 are received, the shuttle truck
is considered to be in lane 1. The tag transmitter battery life
could be five or more years for this type of application.
[0114] FIG. 19 shows possible general locations of tag
interrogators 716 located on a shuttle truck 708. The circles
indicate three tag interrogators 716 on a shuttle truck 708, at
least one tag interrogator located on the top support 708a near the
middle portion of the shuttle truck, and at least one tag
interrogator on each leg 708b near the wheel 708c. Power from the
shuttle truck can operate the tag interrogators 716. No data
interface is required. Two tags could be mounted per tag
interrogator nearby to monitor the health status of each tag
interrogator and maintain high availability of the system.
[0115] FIG. 20 shows a representation of a shuttle truck 708 and
the general location of tag interrogators on the shuttle truck legs
as represented by the rectangular area at the bottom of the shuttle
truck near the wheels. One tag interrogator could be located at
each leg of the shuttle truck as described before. A tag
interrogator could be mounted near the bottom of the shuttle truck
on either leg and/or at the middle of the shuttle truck from the
front-to-back. The tag interrogator also can activate container ID
tags when a tag when a tag is mounted on a container handled by a
shuttle truck, helping in identification of a container.
[0116] FIG. 21 shows five lanes for utility tractor rigs at a
landside rail-mounted gantry crane 730. In this non-limiting
example, one tag interrogator per utility tractor rig 732 is used.
Two health status tags could be mounted and positioned per tag
interrogator. One tag could be mounted per crane lane using a kiosk
mounted system or camera beam mounted system.
[0117] FIG. 22 shows a yard crane area 740 having four location
sensors as location access points 720 to receive the activated tag
transmissions. The access points are ideally positioned to receive
RF tag transmissions from any point in the yard and provide full
coverage. Typically, any devices operative as access points are
positioned on elevated surfaces, for example, utility poles.
[0118] FIG. 23 shows the location of tag interrogator 716 on a top
handler 750 also termed container handler. Typically, hundreds of
such handlers are deployed at many large marine terminals. In this
view, the powered vehicle is at the right (not shown). The actual
"handler" that secures containers is shown. Each side could include
a tag interrogator, with only one illustrated in the figure.
[0119] FIG. 24 is an environmental, perspective view of a tag
interrogator 716 that activates the tags. For example, as noted
before, three tag interrogators could be mounted on a shuttle truck
with an adjustable range of about Ito about 20 feet as shown in the
graph of FIG. 25. The specifications of a tag interrogator 716 in a
non-limiting example are about 36 volts DC input power with an
operating temperature range from about -22 degrees Farenheit to
about 140 degrees Farenheit. The weight of an exemplary tag
interrogator is about 2.2 pounds and has a diameter of about 9
inches and depth of about 5 inches as illustrated in this
non-limiting example. It is a compact device and could be mounted
on a mounting plate for attachment to selected surfaces.
[0120] The tag interrogator is a proximity communication device
that triggers a tag to transmit a "blink" pattern of a radio
frequency signal, typically a spread spectrum signal. When the tag
transmitter passes through the tag interrogator's field, the tag
can initiate a preprogrammed "blink" rate. In a non-limiting
example, the tag interrogator can use a magnetic field-based
communication by generating a rotating AC magnetic field as
generated by a diverse spatial orientation and two-dimensional
arrangement of magnetic field coils, such as described in the
incorporated by reference U.S. Pat. No. 6,812,839 and commonly
assigned to Wherenet Corporation. The AC magnetic field can rotate
over a region of increased sensitivity into which the tag enters
and can be representative of information and intended for the
object or tag entering the region. This information could include
an identification for the device, such as the shuttle truck
described before.
[0121] As shown in FIG. 24, the tag interrogator 716 is disk-shaped
and includes an upper disk-shaped portion 716a and a lower base
716b having a number of support legs 716c that support the tag
interrogator when it is secured onto an object. A data
interface/power terminal 716d is located at the base 716b as
illustrated. The tag interrogator 716 can be programmed as
necessary for identifiers and other functions.
[0122] In a non-limiting example, 80 tag interrogators and 160
health tags can be used with 20 utility tractor rigs and one tag
interrogator per utility tractor rig. Twenty shuttle trucks could
each include three tag interrogators per shuttle truck. Two health
tags could be used per tag interrogator. Two hundred thirteen (213)
tags have been used with 75 tags at the rail-mounted gantry
landside and 90 tags at the rail-mounted gantry waterside.
Forty-eight (48) tags on cranes could be used. Four location
sensors could be used with VSS software such as described
before.
[0123] In accordance with another non-limiting example of the
present invention, permanent tags could be located within or on
pavement areas as described above. For example, single-point tags
provide a "milepost" or location crossing indication. A
line-of-tags could provide a boundary crossing indication. A
grid-of-tags could provide X/Y location information.
[0124] As shown in FIG. 26, the tag interrogators 716 are mounted
on mobile devices as explained before and shown generally at 800 to
excite a tag 712 when in proximity to cause a tag to blink. The
permanent milepost tags transmit to a radio frequency (RF)
infrastructure that includes access points the ID's of both the tag
and tag interrogator as a magnetic signal source. The RF
infrastructure of the RF ID and location system processes the
received signals for various information requirements, including
time of tag (milepost) crossing at which the tag interrogator
passed by the embedded or fixed tag. Multiple crossing data points
using multiple and spaced tags can be used for mobile device route
calculations and integrated data filtering in this non-limiting
example.
[0125] FIG. 26 shows the vehicle 800 and tag interrogator 716. The
magnetic field lines are shown in the dashed circles and are
virtually unaffected by the vehicle body as compared to the RF
signals that could be affected by the vehicle body. The tag
interrogator can also be used as co-location device associated with
a towed or carrying device, for example, a container or trailer. In
this non-limiting example, the tag 712 is "buried" in the pavement
as illustrated. This "buried" tag 712 transmits not only the tag
ID, but also the tag interrogator ID to the RF infrastructure
formed by the access points and processor for further processing.
The system can transmit in configurable, multiple modes such as (1)
immediately upon sensing the tag interrogator when it passes over
the tag; (2) immediately upon exit of the tag interrogator from the
tag area; and (3) delayed either, or both, of above initial
detections in 1 and 2.
[0126] As shown in FIG. 27, a high speed and low speed
implementation for the tag as a road marker with vehicle operation
over pavement 810 when traveling greater or less than 10 mph. A
configuration for greater than 10 mph is shown on the left for high
speed vehicle operation and a configuration for low speed vehicle
operation is shown on the right, i.e., less than 10 mph. Each
design is similar to molded plastic highway markers as cover disks
or plates that are attached to the pavement surface with a special
epoxy. These circular disks or plates are shaped to minimize "tire
feel" to the passing vehicles.
[0127] As shown at the drawing on the left, the high speed
implementation includes the tag 712 that is embedded within a
cylindrical housing 812 such as a molded urethane cylinder that is
embedded within the pavement surface 810. A 2-inch diameter by 3.5
inch hope can be bored in the pavement represented by dimensions B
and C and the hole receives the molded urethane cylinder 812 in
this non-limiting example. The circular plate could be about
4-inches diameter and Q.4 inches high represented by dimensions A
and D. The molded urethane cylinder 812 could be attached to the
underside of the circular plate 814 with epoxy applied on the
underside to adhere to the pavement.
[0128] The right side drawing shows a low speed implementation with
a larger circular plate 816 that is about 12 inches in diameter as
shown in dimension E and about 1.25 inches in height as shown by
dimension F. The tag 712 is embedded within the circular plate,
which can be adhered to the surface 810 as noted before using a
special epoxy or similar adhesive. Different materials can be used
for the construction of the circular plate including the use of
various metals and plastics that are adapted to withstand the heavy
vehicle weight on the pavement 810.
[0129] Many modifications and other embodiments of the invention
will come to the mind of one skilled in the art having the benefit
of the teachings presented in the foregoing descriptions and the
associated drawings. Therefore, it is understood that the invention
is not to be limited to the specific embodiments disclosed, and
that modifications and embodiments are intended to be included
within the scope of the appended claims.
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