RETRIEVAL OF LOST ROAD VEHICLES AND OTHER ARTICLESThis invention relates to a method of and an apparatus for retrieving lost road vehicles, and other movable articles.
Thefts of road vehicles in the United Kingdom (particularly of cars, and of transport lorries and their cargoes) have reached a very high level. Substantial losses are suffered by the owners, their insurers and the national economy.
Retrieval of such lost vehicles is difficult to achieve.
There is so far no systematic method of determining the whereabouts of lost vehicles, so that retrieval, if it occurs at all, occurs on a random basis, and is largely a matter of good luck.
According to one feature of the present invention, in a system for retrieving lost road vehicles (and other lost articles), each road vehicle forming part of said system is provided, in some hidden and unobvious position thereon, with an electronic radio signal generating and transmitting device which is arranged for remote control by a unique radio-transmitted 'vehicle address' signal. In response to stimulation by such an address signal, that device is rendered operative and transmits 'vehicle identity' radio signals which uniquely identify the vehicle carrying the device.
According to a further feature of the present invent ion, there is provided in such system a network of local radio transmitting/receiving stations spaced around a predetermined district, region or country in which such system is to operate. Each such station is capable of transmitting such unique vehicle address signals, and of receiving such vehicle identity signals. Such stations are spaced about in a manner such that their transmission/ reception areas cover the whole of said district, region or country.
According to another feature of the present invention, there is also provided in said system a central supervisory unit for controlling the operation of the respective transmitting/receiving stations, and for monitoring and processing data signals received from said stations. Said supervisory unit preferably includes a data processing means, and a memory containing inter alia a register of the vehicle registration numbers of all of the road vehicles forming part of the system, and for each such registration number, an address code which represents the 'vehicle address' associated with the particular vehicle. Said supervisory unit also includes an input/output circuit through which it receives input signals requesting the location of particular lost road vehicles, and supplies output signals indicating such locations.
According to another feature of the present invention, each such transmitting/receiving station includes direction finding means for determining the bearing relative to a datum of the direction from which a received vehicle identity signal originates, and for supplying to said supervisory unit a signal indicative of said bearing. Each such station may also include distance determining means for determining the distance from the station of a signal generating/transmitting device from which a said identity signal originates, and for supplying to said supervisory unit a signal indicative of said distance.
According to another feature of the present invention, said supervisory unit is programmed to process such bearing signals received from a plurality of such stations, together with stored position data reprentative of the positions of such stations, and to derive therefrom the location of a lost vehicle from which said vehicle identity signals originate. Said supervisory unit may also be programmed, if desired, to process such bearing signals and such distance signals derived from one or more such stations, together with such stored position data, and to derive therefrom the location of a lost vehicle from which said vehicle identity signals originate.
A system according to the present invention embodies the various components referred to above, and operates in the following preferred manner.
On receipt of a request to locate a particular vehicle, the supervisory unit determines from its memory the address code for the particular 'lost' vehicle, and activates the respective transmitting/receiving stations in a predetermined order, transmitting to each of them, inter alia, the address code of the lost vehicle. Each such station, on being activated, transmits a 'vehicle address' radio signal appropriate to the address code.
If the lost vehicle lies within the field of coverage of such a station, the signal generating/transmitting device carried by the lost vehicle becomes activated, and so generates and transmits a 'vehicle identity' radio signal, or preferably a continuing train of such vehicle identity signals. Those signals are received by the station, which thereupon transmits a signal to the supervisory unit to advise it that the lost vehicle has been detected by that station.
The supervisory unit monitors the responses of the respective transmitting/receiving stations, to determine which of the respective stations has detected the presence of the lost vehicle. That unit is programmed to determine which (one, two or more, as necessary) of those responding stations should be activated further in order to determine the exact position of the lost vehicle.
Having made that determination, the respective selected stations are activated, and so caused to carry out radio direction determining processes (and distance determining processes if desired) to determine the respective directions (and distances if desired), relative to a predetermined datum, from which the respective vehicle identity signals are being received by those stations. Signals representative of those directions (and distances if desired) are transmitted by those stations to the supervisory unit, which thereupon processes those direction signals (and distance signals if desired) and other signals representative of the positions of the respective stations to determine the exact location of the lost vehicle.
If desired, as an alternative, the same vehicle identity signal may be emitted by each such radio signal generating and transmitting means when activated. However, such an arrangement has less security against location of vehicles which erroneously respond when a vehicle address is transmitted, and against sources which fortuitously emit the vehicle identity signal.
Other features of the present invention will appear from a reading of the description that follows hereafter, and of the claims appended at the end of that description.
One 'lost' vehicle location system according to the present invention will now be described by way of example and with reference to the accompanying diagrammatic drawing. That drawing shows schematically the various components which comprise the system.
Referring now to the drawing, the system includes a supervisory unit 10 which is linked by landlines (or radio links) 12 with a network of transmitting/receiving stations 14 which are spaced apart around a region of the UnitedKingdom so as to provide full radio transmission/reception coverage of the region. Each such station 14 comprises a radio equipment for transmitting and receiving radio signals, and for determining from which direction received radio signals originate. That radio equipment is controlled in accordance with or by input signals received from the supervisory unit 10.
The supervisory unit 10 incorporates a data processor 16, and a data store 18 in which are stored, inter alia, (a) a register of vehicle registration numbers (one for each road vehicle included in the system), (b) for each such registration number* a unique vehicle address signal, and (c) the locations of the respective stations 14.
The supervisory unit 10 also incorporates an input/output circuit 20 through which it may (a) receive requests to locate 'lost' vehicles having specified registration numbers, and (b) provide the locations of the vehicles which have been found.
Each road vehicle 22 forming part of the system is provided with a signal generator 24 which is arranged to respond to a unique 'vehicle address' signal, and to emit in response thereto a continuing, unique 'vehicle identity' signal.
In response to a request to locate a lost vehicle having a specified registration number, the data processor 16 of the supervisory unit 10 seeks out from the stored register of registration numbers the unique 'vehicle address' signal of the identified vehicle, and then causes that address signal to be transmitted, in a predetermined sequence, to each of the stations 14.
Each such station, on receipt of that address signal transmits a corresponding vehicle address signal by radio throughout its area of coverage.
In the event that the addressed vehicle is not within the area of such a station 14, no vehicle identity signal is received by the station, and the station then transmits to the supervisory unit 10 a signal to indicate the lack of a response to the transmitted address signal.
On the other hand, if the lost vehicle lies within the area of a station 14, the radiation of the vehicle address signal by that station stimulates the signal generator 24 of the lost vehicle, which thereupon emits its vehicle identity signal in response. That signal is received and detected by the station 14, which thereupon transmits a 'vehicle found signal to the supervisory unit 10.
After all of the respective stations 14 have radiated the vehicle address of the lost vehicle, the supervisory unit 10 selects, in accordance with a predetermined program incorporated in its data processor, two (or more) of the stations that have indicated the receipt of vehicle identity signals, and commands them to determine the directions from which the received vehicle identity signals originate.
Those directions are coded and transmitted to the supervisory unit 10, which thereupon deduces, from those coded direction signals and the stored positions of the respective stations 14 from which the coded direction signals originate, the locution of the lost vehicle. That location is transmitted via the input/output circuit to the source of the enquiry.
The stations 14 may be arranged to operate autonomously and automatically under the control of the supervisory unit 10, or they may operate fully under the control of that unit 10.
If desired, the signal generators 24 may be associated instead with specific cargoes being transported on vehicles, so that lost cargoes themselves may be located.
Alternatively, additional signal generators 24 may be associated with such cargoes, so that both lost vehicles and lost cargoes can be independently located.
Any means of direction finding may be used by the stations 14. Moreover, distance determining means may also be associated with the direction finding means, so as to enable each station to determine on its own, as necessary, (at least approximately, within the limits of the apparatus) the bearing and the distance, and hence location, of a lost vehicle or cargo. Such distance finding means may enable the approximate location of a lost vehicle to be determined from one such station 14, though the exact location can be determined from additional signals provided by one or more other stations. In some instances, the approximate location provided by a single station may suffice for the purposes of a requesting party.
The system described above may be used for locating any specified road vehicle, whether it be lost or otherwise.
For example, where an emergency situation arises, and a road vehicle needs to be contacted, the location of that vehicle can be determined by the method described above.
Furthermore, whilst the system described above relates to the location of road vehicles and their cargoes, the system may also be used for the location of any movable or removable article on or in which a signal generator 24 can be planted, for example, a briefcase, or a valuable work of art.