EP0570223A1

EP0570223A1 - Vehicle guidance apparatus

Info

Publication number: EP0570223A1
Application number: EP93303708A
Authority: EP
Inventors: Paul Geoffrey De La Salle; Stephen Robert Dawes; Nigel James Cousins; Philip Michael Anderson
Original assignee: Securicor Datatrak Ltd
Current assignee: Securicor Datatrak Ltd
Priority date: 1992-05-15
Filing date: 1993-05-13
Publication date: 1993-11-18
Also published as: AU3858893A; AU665074B2; CA2096258A1; GB9210470D0; JPH0668393A

Abstract

The present invention provides a vehicle guidance apparatus (10) for use with a mobile transmitter/receiver located on the vehicle, which transmitter/receiver co-operates with a plurality of fixed transmitters/receivers located at spaced apart locations. The mobile transmitter/receiver determines the coordinates of the current location of the vehicle and the guidance apparatus comprises a display unit (18) and various processing means. The processing means includes means for receiving the coordinates of the target destination and means for receiving automatically from the mobile transmitter/receiver the coordinates of the current location of the vehicle. The processing means also includes display generation means, for generating on the display unit (18) a display of the relative directional displacement between the vehicle and the destination.

Description

The present invention relates to vehicle guidance apparatus for use with a mobile transmitter and receiver. For ease of reference, a combined transmitter and receiver is hereinafter referred to as a transceiver. Mobile transceivers have been the subject of extensive research and development in recent years. Particular reference is made to published European patent application number EP 0292182.
European patent application EP 0292182 discloses a communication system comprising a plurality of fixed transceivers located at spaced apart positions in a terrestrial area and mobile transceivers for use in that system. The mobile transceivers, inter alia, receive signals from the fixed transceivers for determining the location of the mobile transceiver within the communication system. The communication system and mobile transceivers can provide an electronic navigation system to position and track vehicles within an established highway infrastructure. It is important to appreciate that such a navigation system is inherently different from conventional direction finding systems.
Conventional direction finding systems have primarily been used in connection with ships and aircraft which can, of course, move unconstrained in many different directions through what is often featureless surroundings. An arrangement of the type disclosed in EP 0292182 can be used to provide a vehicle location system. Such a vehicle location system can be provided at reasonable cost and in a form suitable, for example, for installation in ordinary road going vehicles. The system can be used to enable an operator to establish the location of one or more vehicles in a fleet of such vehicles. Such systems have been used in the United Kingdom over the last four or five years. They have been used in relation to fleets of emergency service vehicles, fleets of security service vehicles and fleets of public transport vehicles (including boats).
In the above described vehicle location system, the individual mobile transceivers determine for themselves their own physical location, ie. map grid reference. This information is transmitted, via one or more of the fixed transceivers, to an operations headquarters. An operator at the headquarters can thus assess routing for the vehicle and/or marshall members of the vehicle fleet. Relevant instructions can then be dispatched to the individual vehicles. These instructions are, in the existing systems, sent by radio telephone type systems which are independent of the fixed and mobile transceivers used for the vehicle location.
The present invention seeks to extend the benefits which can be derived from systems such as the above described vehicle location system.
Thus, according to one aspect of the present invention there is provided a vehicle guidance apparatus for use with a mobile transceiver located on the vehicle which transceiver co-operates with a plurality of fixed transceivers located at spaced apart locations, so as to determine the coordinates of the current location of the vehicle, the guidance apparatus comprising:-

a display unit,
means for receiving the coordinates of a target destination,
means for receiving automatically from the mobile transceiver the coordinates of the current location of the vehicle, and
display generation means for generating on the display unit a display of the relative directional displacement between the vehicle and the destination.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which;-

Figure 1 is a schematic plan view of a vehicle guidance apparatus embodying the present invention, and
Figure 2 is a plan view, similar to figure 1 but showing an alternative form of display.

The vehicle guidance apparatus illustrated in figure 1 is a relatively small electronic unit suitable for mounting in a vehicle. The particular application of the invention which is described in the present embodiment relates to vehicle guidance apparatus for cars and the like. It will be readily apparent from the following description that the vehicle guidance apparatus can be implemented in many different forms, can be used in relation to vehicles generally and that the particular use of the guidance apparatus is in no way restricted to the particular use described below.
The vehicle guidance apparatus shown in figure 1 comprises a unit 10 connected to a mobile transceiver (not shown) via a cable 12. Cable 12 enables the supply of electrical power to unit 10 from the mobile transceiver, as well as providing for data communication between the guidance apparatus 10 and the mobile transceiver.
Housed within unit 10 is an electronic circuit which performs various functions, as will be described. The externally visible components of unit 10 include a numeric keypad 14, a function keypad 16 and a display panel 18.
Numeric keypad 14 has twelve keys, including a respective key for each of digits 0 through 9, for data entry. Of the remaining two keys, one (E) is used to confirm entry of data, while the other (C) is used to clear data before entry is confirmed - if, for example, one of the digit keys is operated erroneously.
Function keypad 16 is shown as including four function keys, marked F1 through F4. These keys can be used to provide special functions, for example zoom-in and zoom-out facilities in relation to displayed data.
Display 18 is readily implemented by a flat panel LCD of the rectangular form shown. All of the images indicated in figure 1 within the rectangular display 18 are generated by the electronic circuitry within unit 10. Particularly, it is to be noted that although figure 1 illustrates the display as divided into three main areas (20, 22, 24), the guidance apparatus can change between different display formats. Some of the display formats may use the whole of the display for a single purpose, other formats may divide the display into different areas.
The images displayed on LCD panel 18 as shown in figure 1 effectively divide the display into three areas 20, 22 and 24. Display area 20 contains alphanumeric information. Display area 22 is a pictorial display illustrating movement of the vehicle towards a target destination. Area 24 is a pictorial display of the bearing which the vehicle should take to reach the target destination.
One particular use of the guidance apparatus will now be explained, with reference to the image displays 20, 22 and 24.
Assume that an incident has occurred which requires the presence of an emergency service vehicle at a particular location. The operator of the emergency service vehicle fleet identifies the precise location of each vehicle in the fleet from the transmissions sent by the mobile transceiver in each vehicle. The most appropriate vehicle to attend the incident is selected using this information. The location of the incident is then relayed to the selected vehicle. In a simple arrangement the information is relayed to the driver of the vehicle by radio telephone or the like. A more sophisticated system can be implemented using the vehicle guidance apparatus of the present invention. In this case, the information can be sent by the system of fixed and mobile transceivers and relayed from the mobile transceiver of the selected vehicle to the vehicle guidance apparatus of that vehicle. In either event, the coordinates of the target destination (site of the incident) is entered into the vehicle guidance apparatus 10. In the more sophisticated arrangement mentioned above, the data entry can be fully automatic. In the simple arrangement, the driver operates one of the function keys, say F1, to initiate a particular mode of operation of apparatus 10. This mode of operation provides a display (not shown) prompting the driver to enter, via numeric keypad 14, the coordinates received from the operational Headquarters.
Once the coordinates of the target destination have been received by apparatus 10, by whichever means, the apparatus starts to form a displayed image of the type depicted in figure 1. The displayed image is divided into the three areas 20, 22 and 24. In display area 20 the standard headings "Search cds:", "Distance;" and "Bearing" are formed. The coordinates of the target destination (in terms of Eastings and Northings) are displayed against the heading "Search cds:". Further information is added to the displayed image in accordance with data received, via cable 12, from the mobile transceiver of the selected vehicle.
The mobile transceiver of the vehicle performs its normal function of identifying the precise current location of the vehicle, by a phase comparison of standard signals transmitted by the fixed transceivers. The current location of the vehicle identified by the mobile transceiver is used by the vehicle guidance apparatus 10 to calculate the distance and bearing of the target location relative to the current location and heading of the vehicle. The distance (straight line) and bearing are subsequently displayed against the relevant heading, as shown in figure 1. As the vehicle moves, the current location is updated by the mobile transceiver and the guidance apparatus makes corresponding updates to the distance and bearing information which is displayed.
The display area 24 displays an image comprising a central point 26 and a direction indicator 28. The displayed image of directional arrow 28 rotates around central point 26 in accordance with the bearing information calculated by the guidance apparatus 10. Display area 24 has a square shape and associated each with a respective side are the headings "Forward", "Backward", "Left" and "Right". a respective side are the headings "Forward", "Backward", "Left" and "Right". The combination of directional arrow 28 with the side headings provides the driver with a readily perceivable indication of the general direction which the vehicle must take in order to reach the target destination. The directional information will of course change as the vehicle moves towards the target destination. The driver will often not be able to move the vehicle directly in the direction indicated by arrow 28, because of constraints such as the roads which are available.
A cross 30 is displayed at the centre of display area 22. Cross 30 indicates the target destination. The display also contains a dot 32 and this indicates the current location of the vehicle. Display area 22 as shown in figure 1 depicts the situation in which the vehicle has moved some distance towards the target destination. Progress of the vehicle towards the target destination is indicated by the trace of the vehicle's movement, indicated by reference numeral 34. The twists and kinks in trace 34 show that movement of the vehicle has been constrained, for example by the road network.
It will be appreciated that relative directional information is displayed in each of the areas 20, 22 and 24. It will further be appreciated that a particular scaling is applied in the case of display 22, in association with display of the relative displacement between the vehicle and the target destination. One of the function keys, say F2, can be associated with a change of scale function, so as to provide a clearer indication of the inherent information - as the vehicle approaches the target destination. It is also possible for the apparatus 10 to provide an automatic change of scale in respect of display 22, when the relative displacement reaches one or more preset values. For example, the scale may increase by a preset amount as the vehicle reaches the distances of 10km, 5km and 1km from the target destination. Of course, as the scale is changed, at least part of trace 34 will be lost.
A further or alternative form of display will now be described with reference to figure 2.
Operation of one of the function keys, say F3, can be used to change the display from that shown in figure 1 to that shown in figure 2. The display shown in figure 2 is one in which the whole of display panel 18 is devoted to the display of a roadway map, upon which the target destination and current vehicle location are indicated. As in figure 1, the target destination is indicated by cross 30 and the vehicle location by dot 32. In figure 2 indicators 30 and 32 are shown displaced from the respective roads, this is for clarity of illustration only. In the actual instrument, indicators 30 and 32 would appear as bright or flashing images actually on the relevant road image. The position of dot 32 does of course change as the vehicle moves towards the target destination.
The roadway map generated for display shown in figure 2 results from data which is stored in the vehicle guidance apparatus 10. This information can be stored directly in a memory device which is an integral part of the electronic circuitry of unit 10. Alternatively, the roadway map information can be stored in a plug-in memory device which the driver vehicle plugs into unit 10. Different plug-in modules can be available to the driver of the vehicle. For example, guidance apparatus 10 may normally operate with a plug-in memory device containing data to generate a map showing all of the main roads in the area covered by that particular emergency service vehicle. The plug-in memory device may then be replaced with an alternative plug-in memory device containing data enabling generation of a detailed street plan of a city centre within the general operating area of the vehicle. Of course, the level of detail (including extra information such as road numbers) depends upon the data stored in the plug-in memory.
The mode of operation explained with reference to figure 2 does, of course, provide generation of a display of the relative directional displacement between the vehicle and the target destination. That is, by itself it forms an embodiment of the broad concept of the present invention. It can also be used to illustrate alternative uses of a specific implementation of the invention. For example, the vehicle guidance apparatus 10 can be installed in association with a mobile transceiver in a private road vehicle, rather than an emergency service vehicle. In this case, the mode of operation depicted in figure 2 might be used to guide the motorist to a particular location in a unfamiliar city centre.
Various operational features can be added for use with the vehicle guidance apparatus. In this respect, it is feasible for traffic information to be included in the broadcast from the fixed transceivers. Such information can be displayed to the driver, or other persons, in a vehicle fitted with a mobile transceiver. The traffic information will be displayed on the LCD panel 18, either in alphanumeric form or in graphical form associated with a display of the type shown in figure 2.
Reference has been made above to the electronic circuitry contained within unit 10. This circuitry is used to provide means for entering the coordinates of the target destination (via keypad 14 or directly from the mobile transceiver), means for receiving automatically from the mobile transceiver the coordinates of the current location of the vehicle, and means for generating on the display unit 18 a display of the relative directional displacement between the vehicle and the target destination. Implementation of the electronic circuitry is well within the average skill of the person in the relevant art, having regard to the aforegoing description. The circuitry need comprise little more than a power supply circuit, a conventional microprocessor and the on-board controller provided in association with modern LCD panels.

Claims

Vehicle guidance apparatus (10) for use with a mobile transmitter/receiver located on the vehicle which transmitter/receiver co-operates with a plurality of fixed transceivers located at spaced apart locations, so as to determine the coordinates of the current location of the vehicle, the guidance apparatus comprising:-
- a display unit (18),

- means for receiving the coordinates of a target destination,

- means for receiving automatically from the mobile transmitter/receiver the coordinates of the current location of the vehicle, and

- display generation means for generating on the display unit (18) a display of the relative directional displacement between the vehicle and the destination.
A vehicle guidance apparatus as claimed in claim 1 wherein:-
- the display generation means generates a display comprising a direction indicator (28) which indicates the direction in which the vehicle should proceed in order to reach the destination.
A vehicle guidance apparatus as claimed in claim 1 or claim 2 wherein:-
- the display generation means generates a display comprising an indicator (30) for the destination and an indicator (32) for the current location of the vehicle.
A vehicle guidance apparatus as claimed in claim 3 wherein:-
- the generated display includes a residual trace (34) of the course of movement of the vehicle.
A vehicle guidance apparatus as claimed in claim 3 or claim 4 wherein:-
- the generated display includes a map of the area in which the destination (30) and the current location (32) of the vehicle are situated.
A vehicle guidance apparatus as claimed in claim 5 wherein:-
- the display generation means includes a plug-in cartridge which provides the data for generation of the map.
A vehicle guidance apparatus as claimed in any of claims 3 to 6 wherein:-
- the said indicators (30, 32) indicate the actual relative displacement of the destination and current location of the vehicle and the guidance apparatus includes scale changing means providing the facility to increase or decrease the scale of representation of the said actual relative displacement.
A vehicle guidance apparatus as claimed in claim 7 wherein:-
- the scale changing means operates automatically to increase the scale when the displacement between the destination and the current location of the vehicle reaches a preset value.
A vehicle guidance apparatus as claimed in any preceding claim wherein:-
- the guidance apparatus includes means for receiving traffic information broadcast by a fixed transmitter/receiver and the display generation means generates a display incorporating the said traffic information.
A vehicle guidance apparatus as claimed in any preceding claim wherein the display generation means generates a display having two portions, one containing a display m accordance with claim 2 and the other containing a display in accordance with claim 3.