GB2271692A - Vehicle location system - Google Patents

Vehicle location system Download PDF

Info

Publication number
GB2271692A
GB2271692A GB9221440A GB9221440A GB2271692A GB 2271692 A GB2271692 A GB 2271692A GB 9221440 A GB9221440 A GB 9221440A GB 9221440 A GB9221440 A GB 9221440A GB 2271692 A GB2271692 A GB 2271692A
Authority
GB
United Kingdom
Prior art keywords
region
vehicle
base station
interrogator
identifying means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9221440A
Other versions
GB2271692B (en
GB9221440D0 (en
Inventor
Philip Henry Wisbey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BAE Systems Electronics Ltd
Original Assignee
GEC Marconi Ltd
Marconi Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GEC Marconi Ltd, Marconi Co Ltd filed Critical GEC Marconi Ltd
Priority to GB9221440A priority Critical patent/GB2271692B/en
Publication of GB9221440D0 publication Critical patent/GB9221440D0/en
Publication of GB2271692A publication Critical patent/GB2271692A/en
Application granted granted Critical
Publication of GB2271692B publication Critical patent/GB2271692B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H04B5/48—
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/82—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted
    • G01S13/825—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted with exchange of information between interrogator and responder
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/87—Combinations of radar systems, e.g. primary radar and secondary radar
    • G01S13/876—Combination of several spaced transponders or reflectors of known location for determining the position of a receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/91—Radar or analogous systems specially adapted for specific applications for traffic control
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/87—Combinations of systems using electromagnetic waves other than radio waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0269—Inferred or constrained positioning, e.g. employing knowledge of the physical or electromagnetic environment, state of motion or other contextual information to infer or constrain a position
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/003—Transmission of data between radar, sonar or lidar systems and remote stations
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/20—Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
    • G08G1/207—Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles with respect to certain areas, e.g. forbidden or allowed areas with possible alerting when inside or outside boundaries
    • H04B5/28—
    • H04B5/77—
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
    • G01S13/933—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft
    • G01S13/934—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft on airport surfaces, e.g. while taxiing

Abstract

A vehicle location system is formed by a central base station 5, an interrogator 3 and transceiver 4 on the vehicle 2 and a plurality of region identifiers 6 arranged in or around the perimeters of a plurality of regions 1, Fig.1, (not shown). The region identifiers identify to the interrogator which region the vehicle is in and the transceiver supplies this identification to the base station. The regions are identified using pseudo-passive transponders, or leaky feeders, or bar codes placed on the ground, and the "interrogator" 3 correspondingly uses R.F. transmission/reception, or R.F. reception, or is an optical (infra red) reader. <IMAGE>

Description

VEHICLE LOCATION SYSTEM This invention relates to a system for monitoring vehicle locations and particularly to a system for monitoring vehicle locations at airports.
Airports use large fleets of service vehicles to carry out and support various tasks around the airport and it is important to be able to keep track of the locations of all of these vehicles. Generally many of these service vehicles are not operated by the airport authority but by outside organisations.
Although it is possible to keep track of service vehicles using ground radar and vehicle mounted transponders this is a very expensive system to set up and suffers from reliability problems due to shadowing by aircraft and buildings.
Systems intended to overcome this problem by having the vehicle keep track of its location and supply this information to a central authority on request have been proposed but these suffer from the problem that they require sophisticated and expensive navigation systems, such as inertial navigation systems or systems which integrate the movement of the wheels, to be mounted on every vehicle.
This invention was intended to provide a vehicle location monitoring system overcoming these problems, at least in part.
This invention provides a vehicle location system for identifying which of a plurality of regions a vehicle is in and comprising a vehicle mounted unit including an interrogator and a transceiver, identifying means associated with each region and a base station and arranged so that in use the identifying means identifies to the interrogator which region the vehicle is in and the transceiver supplies this region identification to the base station.
This allows the problem of shadowing to be overcome because active radar is not used and does not require a sophisticated navigation system to be mounted on each vehicle.
A system embodying the invention will now be described by way of example only with reference to the accompanying diagrammatic Figures in which: Figure 1 shows a part of an airport employing a vehicle location system according to the invention; Figure 2 shows a vehicle and the parts of the system in communication with it in the system of Figure 1; and Figure 3 shows the equipment contained in the vehicle of Figure 2 in more detail, similar parts having the same reference numerals throughout.
Referring to Figure 1 an airport is divided into a plurality of different regions, 1A, 1B, 1C, etc. The size of the regions 1 varies in dependence on degree of locational accuracy required for vehicles in that region 1.
For example it may be sufficient to know only that a vehicle is in a specific car park without knowing where it is within the car park whereas it may be necessary to know the position of a vehicle on or adjacent to a runway with great accuracy for safety reasons. It will be realised that only a small part of an airport is shown in Figure 1.
Referring to Figure 2, each vehicle 2 contains an interrogator 3 linked to a transceiver 4. At a central location on the airfield there is a base-station 5 able to carry out two-way communication with each of the vehicle transceivers 4.
The boundaries of each of the regions 1 are defined by a number of pseudo-passive transponders (PPT) 6A, 6B, 6C etc which respond to interrogation by a radio frequency (R.F.) signal from a vehicle mounted interrogator 3 by modulating the R.F. signal returned by the PPT 6 to the interrogator 3. The modulation applied by each PPT 6 is dependent on the area it defines so that the vehicle 2 can tell which region 1 it is in or is entering, from the response from the PPT's 6. The modulation applied by each regions PPT's 6 must be unique and where there are a plurality of PPT's 6 in a region 1 all of the PPT's 6 apply the same modulation.
Where the regions 11 are small they can be defined using a single PPT 6 in the middle of the region 1, as shown in region 1B in Figure 1. However larger regions are defined by a plurality of PPT's 6 spaced around their perimeters, as shown in region 1R in Figure 1.
Referring to Figure 3 the interrogator 3 comprises an antenna 3A linked to a transmitter 3B and a receiver 3C.
The transmitter 3B generates an R.F. interrogation signal at regular intervals and sends it through the antenna 3A.
The interval between interrogation signals must be short enough that it is not possible for a vehicle 2 to pass into, through and out of, the response region of a PPT 6 without interrogating that PPT 6 at least once.
The PPT's 6 return a signal modulated with a location code to interrogator 3 and it is received by a receiver 3C linked to the antenna 3A. The receiver 3C passes the modulated signal to a de-modulator 3D which demodulates the signal and passes this demodulated signal, the location code, to a memory unit 3E where it is stored until it is overwritten by the next demodulated location code signal.
When the base station 5 wishes to know the location of a vehicle 2 it sends a radio signal demanding the location of the vehicle 2 and including the identification code of the vehicle 2. This is received by an antenna 4A and a receiver 4B both forming part of the transceiver 4 in the vehicle 2. The signal received by the receiver 4B is passed to a processor 4C which compares the vehicle identification code included in the signal with the vehicle identification code unique to the vehicle 4 and stored in a memory 4D. If the two codes are the same the processor 4C instructs a radio transmitter 4E to transmit the location code stored in the memory unit 3E and the vehicle identification code stored in the memory unit 4D back to the base station 5 using the antenna 4A.
Thus the base station 5 can keep track of the locations of all of the vehicles on the airfield by asking them in turn where they are.
The data in the memory 3E giving the current location of the vehicle is always the location code of the area 1 the vehicle 2 is currently in even when the vehicle 2 is not within interrogation range of any of the PPT's 6, the location code will only change when a new area 1 is entered and the new location code is overwritten over the old one.
The interrogator 3 and transceiver 4 can both be produced as a single sealed unit with a permanently connected power source, such as an internal battery kept topped up by the vehicle electrical system, and placed in an inaccessible location on the vehicle in order to prevent subversion of the system.
In order to ensure good coverage of the entire airfield a number of transmitters all linked to the base station 5 can be used to demand and receive the vehicle locations.
Any failure by a vehicle to respond to a demand for its location should be rare so any such failure can be investigated without the workload due to false alarms becoming unmanageable.
In addition to the location code the vehicle could be arranged to tell the base station 5 whether or not it is moving, this information could be obtained by a sensor linked to the wheels.
The vehicle transceiver 4 could be arranged to send a location code to the base station 5 at regular intervals rather than on demand, this could be a continuous function or could occur only when the vehicle 2 is moving. Such an automatic sending system will generally require the setting up of timeslots for different vehicles to use. Instead of having a dedicated radio communications system to allow the base station 5 to contact the transceivers 4 timeslots within existing voice radio communications channels could be used.
The location codes used by the PPT's can be fixed or altered regularity to increase security. Where a single region is defined by a plurality of PPT's they could use different location codes provided the base station knew that they all corresponded to a single region.
As well as allowing vehicles 2 to supply location data to the base station 5 when demanded by the base station 5 the system could easily be arranged to allow for the base station 5 to demand location data from all vehicles 2, or all vehicles 2 in a given region 1 or group of regions 1, in this case some form of time delay in sending answers could be used to prevent the base station 5 being confused by a plurality of simultaneous answers being received.
The advantage of using PPT's is that only a relatively small number of PPT's are required to define each region 1, however it may be difficult to precisely define the boundaries between the regions using PPTs because the area within which each PPT can be received depends on atmospheric conditions and can also be altered by reflections from vehicles and as a result there may be some ambiguity in the location information produced.
An alternative approach able to define the boundaries between regions unambiguously is to lay a "leaky feeder" around the perimeter of each region 1.
This leaky feeder would be formed by a shielded cable carrying a radio frequency (R.F.) signal, the shielding being incomplete so that the R.F. signal leaks out and is transmitted into the region around the cable. The amount of R.F. energy which leaks out, and hence the range at which it can be received, can be controlled very accurately by the degree of shielding and the power of the R.F. signal fed into the cable.
In a system employing leaky feeders to mark the boundaries between the regions 1 a vehicle installation like that of Figure 1 is used with the interrogator 3 replaced by a receiver tuned to the frequency of the R.F. signal emitted by the leaky feeders.
There are a number of ways of using leaky feeders to define the boundaries of the regions 1. The simplest is to place a loop of leaky feeder cable around each region 1 just within the boundary, and feed each cable loop with a modulated R.F. signal uniquely identifying the region. The region identity being received by the receiver is transmitted by the transceiver 4 to the base station.
The vehicle 2 will only receive a region identity from a leaky feeder when it is near a region boundary, so the receiver includes a memory device which supplies the last region identity received to the transceiver until the region identity stored in the memory is overwritten by new identity.
This system will leave a narrow area between adjacent regions 1 where either no region identity is received or two region identities are received, depending on the separation and signal power of the leaky feeder cables in adjacent regions 1. It may be that this small area of ambiguity is acceptable, particularly where no identity is received in the area between adjacent regions because in this case the vehicle will retain the identity of the last region it was in in memory.
If this ambiguity is not acceptable the leaky feeder cables in adjacent regions 1 must have their separation and power arranged so that both of their signals can be received in the area between them and the receiver must be able to sense which of the two leaky feeder cables is closest and provide the identity of the closest leaky feeder cable as the present location of the vehicle.
This can be done either by the receiver sensing the relative powers of the two signals and taking the most powerful to be closest or by the two signals from the two leaky feeder cables containing a time synchronised modulation so that the receiver can calculate the relative travel times and hence ranges, of the signals from the two cables.
An alternative arrangement which does not suffer from this ambiguity uses essentially the same apparatus aboard the vehicles 2 but uses only a single leaky feeder cable along each boundary between two regions. The signals supplied to the leaky feeders are modulated so that each boundary is uniquely identified.
Clearly, provided the starting region 1 of a vehicle 2 is known, it will always be possible to calculate which region 1 it is in from the boundaries it has crossed.
This calculation can be carried out by the receiver on board the vehicle 2 and the position information sent to the base station 5 or alternatively the boundary crossing information could by sent to the base station 5 which would then calculate the actual position of the vehicle 2.
In order to eliminate any possible ambiguity the transceiver 4 on the vehicle can be arranged to tell the base station 5 whether the most recently received boundary identity is being taken from memory or is currently being received. From the most recently received boundary identity it is known that the vehicle 2 must be in a specific new region 1 or is in the boundary area between that region 1 and its last region 1. If the boundary identity is coming from memory the vehicle 2 is in the specific new region 1 while if the boundary identity is currently being received the vehicle 2 must be in the boundary area.
It might be expected that leaky feeder cables would be expensive to lay because of the need to cut trenches across roads, but this would not necessarily be the case where concrete roads and runways are used because the leaky feeder cables could be inserted into existing expansion joints in the concrete.
Another alternative allowing the region boundaries to be precisely defined would be to place bar codes on the ground where they could be read by an optical reader mounted on each vehicle 2. The bar code information would be treated like that obtained from the leaky feeders, except that there would be no possibility of overlap and the boundary area between two regions 1 would be only as thick as the bar code marking.
Although it has been said that when boundary codes are used they must uniquely identify the boundary this does not mean that all boundaries in the system must have different identities (globally unique) but means that whichever region 1 a vehicle 2 is in all of the boundaries which it could cross must have different identities (locally unique). The use of globally unique boundary identities may be preferred however in order to allow the position of a vehicle whose start position is unknown to be quickly deduced.
If bar codes were used, security could be increased by using bar codes invisible to the human eye, such as bar codes visible only in infra red light.
All communications within the system can of course be encrypted or encoded for security if desired.

Claims (10)

1. A vehicle location system for identifying which of a plurality of regions a vehicle is in and comprising a vehicle mounted unit including an interrogator and a transceiver, identifying means associated with each region and a base station and arranged so that in use the identifying means identifies to the interrogator which region the vehicle is in and the transceiver supplies this region identification to the base station.
2. A system as claimed in Claim 1 in which a region has identifying means arranged around its perimeter only.
3. A system as claimed in Claim 2 in which each region has identifying means arranged around its perimeter only.
4. A system as claimed in Claim 2 or Claim 3 in which the identifying means . can identify the region to the interrogator only around the perimeter of the region and the vehicle mounted unit includes a memory device which stores the most recent region identification, where the transceiver supplies the region identification stored in the memory to the base station.
5. A system as claimed in any preceding claim in which the vehicle supplies the region identification to the base station in response to a request from the base station.
6. A system as claimed in any of Claims 1 to 4 in which the vehicle supplies the region identification to the base station at pre-arranged times.
7. A system as claimed in any preceding claim in which radio communication is used between the base station and the transceiver.
8. A system as claimed in any preceding claim in which the identifying means are bar codes and the interrogator is a bar code reader.
9. A system as claimed in any of Claims 1 to 7 in which the identifying means are pseudo-passive transponders and the interrogator is an R.F. transmitter.
10. A system substantially as shown in or as described with reference to the accompanying drawings.
10. A system as claimed in any of Claims 1 to 7 in which the indentifying means is an R.F. transmitter and the interrogator is an R.F. receiver.
11. A system substantially as shown in or as described with reference to the accompanying drawings.
Amendments to the claims have been filed as follows 1. A vehicle location system for identifying which of a plurality of regions a vehicle is in and comprising a vehicle mounted unit including an interrogator and a transceiver, identifying means associated with each region and a base station, at least qne region having identifying means around its perimeter only and arranged so that in use the identifying means identifies to the interrogator which region the vehicle is in and the transceiver supplies this region identification to the base station.
2. A system as claimed in Claim in which each region has identifying means arranged around its perimeter only.
3. A system as claimed in Claim 1 or Claim 2 in which the identifying means can identify the region to the interrogator only around the perimeter of the region and the vehicle mounted unit includes a memory device which stores the most recent region identification, where the transceiver supplies the region identification stored in the memory to the base station.
4. A system as claimed in any preceding claim in which the vehicle supplies the region identification t 'the base station in response to a request from the base station.
5. A system as claimed in any of Claims 1 to 3 in which the vehicle supplies the region identification to the base station at pre-arranged times.
6. A system as claimed in any preceding claim in which radio communication is used between the base station and the transceiver 7. A system as claimed in any preceding claim in which the identifying means are bar codes and the interrogator is a bar code reader.
* 8. A system as claimed in any of Claims l to 6 in which the identifying means are pseudo-passive transponders and the interrogator is an R,F, transmitter.
9. A system as claimed in any of Claims 1 to 6 in which the indentifying means is an R.F. transmitter and the interrogator is an R.F. receiver.
GB9221440A 1992-10-13 1992-10-13 Vehicle location system Expired - Fee Related GB2271692B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9221440A GB2271692B (en) 1992-10-13 1992-10-13 Vehicle location system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9221440A GB2271692B (en) 1992-10-13 1992-10-13 Vehicle location system

Publications (3)

Publication Number Publication Date
GB9221440D0 GB9221440D0 (en) 1992-11-25
GB2271692A true GB2271692A (en) 1994-04-20
GB2271692B GB2271692B (en) 1997-04-09

Family

ID=10723336

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9221440A Expired - Fee Related GB2271692B (en) 1992-10-13 1992-10-13 Vehicle location system

Country Status (1)

Country Link
GB (1) GB2271692B (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998038554A1 (en) * 1997-02-28 1998-09-03 Siemens Aktiengesellschaft Guidance system for a mobile unit and operating method
EP0892380A1 (en) * 1997-07-16 1999-01-20 Koninklijke KPN N.V. System for traffic control
EP0961134A1 (en) * 1998-05-29 1999-12-01 Mitsubishi Denki Kabushiki Kaisha Moving object high-accuracy position locating method and system
WO2001046934A1 (en) * 1999-12-21 2001-06-28 Zakrytoe Aktsionernoe Obschestvo 'east Line-Handling' Real-time tracking and management of land-based vehicles on airports
EP1287374A2 (en) * 2000-06-07 2003-03-05 Symbol Technologies, Inc. Wireless locating and tracking systems
SG96531A1 (en) * 1995-02-02 2003-06-16 Ibm System and method for tracking vehicles in vehicle lots
FR2843475A1 (en) * 2002-08-06 2004-02-13 Groupe Sofide Transport and or fleet management system, in which fleet vehicles are equipped with low range transceivers and exchange information with a central station by using other vehicle transceivers as relay stations
US6988080B2 (en) * 2001-02-16 2006-01-17 Zack Robert E Automated security and reorder system for transponder tagged items
WO2015024686A1 (en) * 2013-08-22 2015-02-26 Atlas Copco Industrial Technique Ab A localization system for a movable power tool.

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1277604A (en) * 1969-11-11 1972-06-14 Ferranti Ltd Improvements relating to position-locating means
US3757290A (en) * 1971-03-12 1973-09-04 Sperry Rand Corp Automatic vehicle monitoring system
US3940630A (en) * 1974-10-21 1976-02-24 Mcdonnell Douglas Corporation Vehicle locator
US4083003A (en) * 1973-11-05 1978-04-04 Products Of Information Technology, Inc. Vehicle location system
US4099591A (en) * 1976-09-02 1978-07-11 Westinghouse Electric Corp. Vehicle control scanning system
US4107689A (en) * 1976-06-07 1978-08-15 Rca Corporation System for automatic vehicle location
GB1543910A (en) * 1976-04-20 1979-04-11 Plessey Co Ltd Vehicle communication systems
EP0199266A1 (en) * 1985-04-17 1986-10-29 Siemens Aktiengesellschaft Mobile radio system
GB2223380A (en) * 1988-07-27 1990-04-04 Shorrock Ltd Personnel location system
GB2239758A (en) * 1990-01-04 1991-07-10 Stc Plc Navigation facility for cellular telephones
GB2254756A (en) * 1991-04-11 1992-10-14 Q M Systems Limited Personnel location monitoring system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1257692A (en) * 1969-07-28 1971-12-22

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1277604A (en) * 1969-11-11 1972-06-14 Ferranti Ltd Improvements relating to position-locating means
US3757290A (en) * 1971-03-12 1973-09-04 Sperry Rand Corp Automatic vehicle monitoring system
US4083003A (en) * 1973-11-05 1978-04-04 Products Of Information Technology, Inc. Vehicle location system
US3940630A (en) * 1974-10-21 1976-02-24 Mcdonnell Douglas Corporation Vehicle locator
GB1543910A (en) * 1976-04-20 1979-04-11 Plessey Co Ltd Vehicle communication systems
US4107689A (en) * 1976-06-07 1978-08-15 Rca Corporation System for automatic vehicle location
US4099591A (en) * 1976-09-02 1978-07-11 Westinghouse Electric Corp. Vehicle control scanning system
EP0199266A1 (en) * 1985-04-17 1986-10-29 Siemens Aktiengesellschaft Mobile radio system
GB2223380A (en) * 1988-07-27 1990-04-04 Shorrock Ltd Personnel location system
GB2239758A (en) * 1990-01-04 1991-07-10 Stc Plc Navigation facility for cellular telephones
GB2254756A (en) * 1991-04-11 1992-10-14 Q M Systems Limited Personnel location monitoring system

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SG96531A1 (en) * 1995-02-02 2003-06-16 Ibm System and method for tracking vehicles in vehicle lots
WO1998038554A1 (en) * 1997-02-28 1998-09-03 Siemens Aktiengesellschaft Guidance system for a mobile unit and operating method
EP0892380A1 (en) * 1997-07-16 1999-01-20 Koninklijke KPN N.V. System for traffic control
EP0961134A1 (en) * 1998-05-29 1999-12-01 Mitsubishi Denki Kabushiki Kaisha Moving object high-accuracy position locating method and system
US6072421A (en) * 1998-05-29 2000-06-06 Mitsubishi Denki Kabushiki Kaisha Moving object high-accuracy position locating method and system
WO2001046934A1 (en) * 1999-12-21 2001-06-28 Zakrytoe Aktsionernoe Obschestvo 'east Line-Handling' Real-time tracking and management of land-based vehicles on airports
SG96582A1 (en) * 1999-12-21 2003-06-16 Zakrytoye Aktsionernoye Obsche The technique of real-time tracking and management of land-based vehicles of the airport
EP1287374A2 (en) * 2000-06-07 2003-03-05 Symbol Technologies, Inc. Wireless locating and tracking systems
EP1287374A4 (en) * 2000-06-07 2005-04-20 Symbol Technologies Inc Wireless locating and tracking systems
US6988080B2 (en) * 2001-02-16 2006-01-17 Zack Robert E Automated security and reorder system for transponder tagged items
FR2843475A1 (en) * 2002-08-06 2004-02-13 Groupe Sofide Transport and or fleet management system, in which fleet vehicles are equipped with low range transceivers and exchange information with a central station by using other vehicle transceivers as relay stations
WO2015024686A1 (en) * 2013-08-22 2015-02-26 Atlas Copco Industrial Technique Ab A localization system for a movable power tool.

Also Published As

Publication number Publication date
GB2271692B (en) 1997-04-09
GB9221440D0 (en) 1992-11-25

Similar Documents

Publication Publication Date Title
US5530440A (en) Airport surface aircraft locator
US5554982A (en) Wireless train proximity alert system
EP0522040B1 (en) Locating system
US20200258392A1 (en) Navigation techniques for autonomous and semi-autonomous vehicles
RU2120130C1 (en) System of transport facility identification in airport
US4197536A (en) Airport surface identification and control system
US4179695A (en) System for identification of aircraft on airport surface pathways
US5400031A (en) Airport surface vehicle identification system and method
US7479919B2 (en) Surface vehicle transponder
ES2300480T3 (en) RADIO-FOLLOW-UP OF VEHICLE MOVEMENTS.
EP0416692A2 (en) Communicating information by radio
US5351032A (en) Power line detection system
CN106527483A (en) Unmanned plane active threat avoiding system based on air traffic control data link
US4939522A (en) Method and system for monitoring vehicle location
US7835827B2 (en) Methods, systems and computer program products for communicating auditory alert to aircraft
GB2271692A (en) Vehicle location system
WO1995003598A1 (en) Locating/map dissemination system
EP1690243B1 (en) Onboard device on a vehicle for traffic surveillance systems in an airport area
CN112435506A (en) Hybrid unmanned aerial vehicle surveys and dodges system
WO1995033214A1 (en) A system for tracking objects
GB2215933A (en) Proximity detection
GB2073530A (en) Secondary radar
JP2886325B2 (en) Relative position measurement system for nearby vehicles
JPH05166100A (en) Airport control system
GB2268031A (en) Automobile sensing and communicating transponder

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19970709