GB2421829A

GB2421829A - System for sending guidance messages to vehicles approaching a controlled zone relating to the vehicle's movement across the zone

Info

Publication number: GB2421829A
Application number: GB0428369A
Authority: GB
Inventors: Gottlieb Schwarz
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 2004-12-29
Filing date: 2004-12-29
Publication date: 2006-07-05
Also published as: GB0428369D0

Abstract

A system for controlling the movements of vehicles 101, 103, includes a first communication unit 114, 115 on the vehicle and a controller 116 associated with a controlled traffic zone 109 with a second communication unit. Both of the units send and receive radio communications 117, 118, 131. The vehicle sends data including the current location, eg GPS, of the vehicle to the controller. The controller sends back a message including a guidance message relating to the movement of the vehicle as it approaches the controlled zone that the vehicle has to cross. The controller is associated with the controlled zone and may control the traffic signals 108 controlling the controlled zone. The guidance may be provided so that the vehicle has the minimum delay at the controlled zone. The guidance message may include details relating to the speed of approach to the controlled zone and may be in the form of instructions or advice. The controller may have details of the planned route/journey of the vehicle. The controller may sent the messages when the vehicle reaches a set distance from the controlled zone and stop sending when the vehicle has left the controlled zone.

Description

TITLE: SYSTEM, METHOD, COMMUNICATION UNIT AND CONTROLLER

FOR USE IN VEHICLE MOVEMENT CONTROL

FIELD OF THE INVENTION

The present invention relates to a system, a method, a communication unit and a controller for use in vehicle movement control. In particular, the invention relates to control of the movement or speed of a public transport or other vehicle based upon its current location.

BACKGROUND OF THE INVENTION

In large towns and cities, public transport systems are employed wherein the location of public transport vehicles is monitored. These systems may include equipment on each vehicle which provides radio communication of information including information about location of the vehicle gathered by a location estimating device such as a GPS (Global Positioning System) terminal. The communication of location information in known systems is sent when the vehicle reaches certain pre-determined places on its route. Such systems also include at least one fixed vehicle traffic control station where information relating to the movement and location of the vehicles is received by radio communication from the vehicles and is stored and displayed on a master control screen.

In such systems, it is known for the traffic control station to send messages to vehicles by wireless communication to control the speed of the vehicles. Such messages may for example be received via a communication unit on the vehicle. The communication unit may be same as that which sends location information. Such messages are provided as an output to the driver, e.g. as an audible or visual message, to advise or instruct the driver of the vehicle to drive faster or to drive slower or even to stop for a while or, if the vehicle has already stopped, to start moving again.

In the known systems, the local traffic conditions encountered by the vehicle are not normally taken into account in guidance of the vehicle movement from the traffic control station.

SUMMARY OF THE INVENTION

The inventor has recognised that the guidance or control of movement of a vehicle can be done in conjunction with the control of a localised zone, e.g. each localised zone controlled by a traffic signal, through which the vehicle has to pass.

According to the present invention in a first aspect there is a system for control of the movement of a vehicle, the system being as defined in claim 1 of the accompanying claims.

According to the present invention in a second aspect there is a method for control of the movement of one or more vehicles, the method being as defined in claim 18 of the accompanying claims.

According to the present invention in a third aspect there is a controller operable to control of the movement of a vehicle, the controller being as defined in claim 21 of the accompanying claims.

According to the present invention in a fourth aspect there is a communication unit for mounting on vehicle, the communication unit being as defined in claim 30 of the accompanying claims.

According to the present invention in a fifth aspect there is a vehicle control station as defined in claim 31 of the accompanying claims.

Further features of the invention are disclosed in the accompanying dependent claims and in the description of embodiments of the invention given later in this

description.

By the invention, a local controller which controls a local controlled zone, e.g. traffic signal controller which controls a traffic signal employed to control the flow of traffic across a zone, is operable to receive signals giving information about the current location of a vehicle. This may be done in a manner similar to that described in Applicant's copending UK Patent Application No. 0427000.5. However, by the present invention, the controller employs the information to estimate when it will be suitable for the vehicle to arrive at the controlled zone in order to cross the controlled zone with minimum delay. The local controller has an associated transmitter which sends a communication to a particular vehicle giving a message that the vehicle should proceed more quickly or more slowly to reach the controlled zone when the traffic signal will allow it to pass without delay. For example where the message is to proceed more slowly, it may be suitable for the vehicle to stay longer at a passenger stop to give passengers a better opportunity to embark or disembark from the vehicle.

Thus, the movement of a vehicle is controlled or assisted in conjunction with a controlled zone, e.g. a zone controlled by a traffic signal regulating traffic flow across the zone. The movement is thereby controlled or assisted locally, with reference to local control of the zone that the vehicle has to cross, rather than centrally by a control station. The local control or assistance of the vehicle movement may come into effect only when the vehicle is detected (by the local controller) to be within a given distance of the controlled zone. The vehicle may also be controlled by the central station when it is detected to be in a region which is outside the control of the local controller, e.g. a region which has no traffic signal controllers.

The invention beneficially allows the movement of a vehicle to be controlled better locally to allow more efficient crossing of a local traffic signal controlled zone.

The vehicle which is controlled using the invention may be a public transport vehicle such as a bus, tram or train.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a street layout illustrating traffic signal control by an embodiment of the invention.

FIG. 2 is a block schematic diagram showing more detail of a traffic signal controller shown in FIG. 1.

FIG. 3 is a block schematic diagram showing more detail of a command and communication unit mounted on a vehicle in the layout shown in FIG. 1.

FIG. 4 is a block schematic diagram of more detail of a vehicle control station of the layout shown in FIG. 1.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

A street layout 100 is shown in FIG. 1. A first public transport vehicle 101 is travelling along a first street 102 and a second public transport vehicle 103 is travelling along a second street 104 running perpendicular to the first street 102. The first street 102 crosses the second street 104 at an intersection region 105. Other traffic is present in the street layout 100 but for simplicity is not shown in FIG. 1.

Traffic flow across the intersection 105 is controlled by a set of traffic light indicators 108.

Each traffic light indicator 108 of the set includes at least a red light and a green light. It may include also an amber light depending on the light sequence normally used by the set. All of the indicators 108 of the set show the same colour of light at the same time for a given direction of traffic flow. Within a controlled zone 109 shown enclosed by a dashed line, traffic is allowed to proceed in one direction only at a time across the intersection 105. A traffic light controller unit 113 is connected to the traffic light indicators 108 and controls operation of the traffic light indicators 108 so that for each given traffic flow period, say 20 seconds, when traffic is allowed to move across the intersection 105, only that traffic in the controlled zone 109 which is to travel in one particular direction, say to continue along the first street 104 from left to right as seen in FIG. 1, is allowed to move across the intersection 105. Conventionally, the traffic light controller unit 113 issues signals to the traffic light indicators 108 to show either green or red depending on the direction they are facing to permit the correct directional flow during each traffic flow period. Thus, for each traffic light indicator 108 the colour shown alternates between red and green during the traffic flow periods. In between each traffic flow period there is also a traffic stop period in which traffic in the controlled zone 109 is stopped from crossing the intersection 105 in all directions to clear the intersection 105 of already moving traffic.

A communication unit 114 is mounted on the vehicle 101. A similar communication unit 115 is mounted on the vehicle 103 and similar units are mounted on other public transport vehicles operating in the town or city having the street layout 100. The unit 114, the unit 115 and other similar units (not shown) send radio communications to a public transport vehicle control station 116. Communications 117 and 118 from the units 114 and 115 respectively are shown in FIG. 1. The information contained in each communication includes an estimate of the current location of the vehicle. Thus, the information in the communication 117 from the communication unit 114 on the vehicle 101 indicates the current location of the vehicle 101. This may for example have been estimated using a GPS (Global Positioning System) receiver included in the command and communication unit 114. The radio communications from the communication units on board each of the public transport vehicles which are sent to the control station 116 are also picked up by the traffic light controller units. Thus, the communication 117 from the communication unit 114 on the vehicle 101 is picked up by the traffic light controller unit 113 as well as by the control station 116.

The traffic light controller unit 113 is shown in more detail in FIG 2. The controller unit 113 includes a receiver 120 which is able to pick up the communication 117, a processor 121 which is able to process data, including information retrieved from the received communication 117 and a memory 122 which stores data and programs used to operate the processor 121 and other components of the unit 113 as well as information received in communications such as the communication 117. The controller unit 113 also includes a timer 123 connected to the processor 121 and a light operation selector 124. Using timing information from the timer 123 the processor 121 is able to provide signals to the selector 124 which in turn switches the state of the indicators 108 in a predefined pattern with time in a well known manner.

The processor 113 is also able to use information included in the communication 117 received via the receiver 120 to determine a direction in which the vehicle 101 is travelling and to determine when the vehicle 101 is approaching the controlled zone 109. The processor 121 may be able to pick up from the received signal an identifier code which indicates the identity of the vehicle 101. The processor 121 can compare this with a route description for that vehicle previously stored in the memory 122 and from that information determine that the vehicle 109 has to cross the intersection 105.

The processor 121 employs the information to estimate when it will be suitable for the vehicle 101 to arrive at the controlled zone 109 in order to cross the intersection 105 with minimum delay. The traffic signal controller 113 has an associated transmitter 125 which sends a communication to the vehicle 101 giving a message generated by the processor 121 indicating how the vehicle 101 should adjust its speed of approach, if at all, of the controlled zone 109. For example, the message may indicate that the vehicle 101 should proceed more quickly or more slowly to reach the controlled zone 109 when the traffic signal indicators 108 will allow it to pass without delay. For example, where the message is to proceed more slowly, it may be suitable for the vehicle to stay longer at a passenger stop to give passengers a better opportunity to embark or disembark from the vehicle.

For example, the processor 121 may determine when the vehicle 101 is estimated to be within 200 metres of the controlled zone 109. When the processor 121 makes that determination, it begins to issue messages to control the speed of the vehicle 101. The processor 121 may continue to monitor the position and movement of the vehicle 101 and issue messages indicating any speed adjustment needed. Alternatively, or in addition, the processor 121 may issue a message indicating that the vehicle 121 is proceeding at a correct speed.

When the vehicle 101 has passed the controlled zone 109 by a sufficient distance, say 100 metres, this is detected by the processor 121 of the traffic light controller 113 again by location information in the received communication 117. The processor 121 can thereby determine that it should stop monitoring the position and movement of the vehicle 101 and consequently stop such monitoring and stop sending movement guidance or control messages to the vehicle.

FIG. 3 is a block schematic diagram of the communication unit 114 on board the vehicle 101. This is the same as the unit 115 on the vehicle 103 and corresponding units on other vehicles operating in the public transport system. The unit 114 is a radio communication unit and includes as its central basic component a processor 301. The processor 301 is connected to a receiver 302 for receiving incoming radio signals and a transmitter 303 for transmitting outgoing radio signals. The unit 114 also has a memory 305 which stores data and programs needed by the processor 301 in operation. The unit 114 also has a user interface 306.

This allows the driver or other responsible person on the vehicle 101 to send and receive messages by radio communication. The messages may be speech messages or data messages or even picture or video messages. The user interface 306 includes a user input device 307 which allows the user to send information messages. The user input device may include a microphone and/or a keypad to enter alphanumeric or other data. The messages by the responsible person are normally sent to the control station 116 although they could alternatively be sent to other destinations, such as other vehicles.

The unit 116 also includes a GPS receiver 304 which is connected to the processor 301. The GPS receiver 304 receives signals from GPS satellites and the processor 301 is able to estimate from the information obtained from these received signals the current location of the vehicle 101. Information relating to the estimate is included in the communication 117 referred to earlier.

The communication 117 is sent by the transmitter 303 to the control station 116 and to traffic signal controllers such as the controller 113 described earlier. The location information is updated regularly and repeatedly sent in the communication 117.

Communications from a user of the unit 114, e.g. to the control station 116, are also sent via the transmitter 303.

The user interface 306 of the unit 114 also includes an output user device 308. This includes one or more output transducers which provide information to the user of the unit 114. These may for example include a speaker to provide audible speech messages. The user desirably can obtain the information in a hands free mode from the speaker. For example, the speaker may be included in a headset to be worn by the driver of the vehicle 101. The output transducer(s) may also include a display to show visible output information.

The instruction messages sent by the traffic signal controller 113 are received by the receiver 302 and processed by the processor 301 and provided as outputs to the driver or other responsible user at the output device 308 of the user interface 306. The instruction messages which are output may be in the form of an audible message or signal or a displayed visual signal or message or a combination of the two. In some applications, wherein the vehicle is an automatically controlled or driverless vehicle the instruction messages received could be acted upon by a control device controlling movement of the vehicle. Messages from the control station 116 or from other terminals are also received by the receiver 302, processed by the processor 301 and provided as an output in a similar manner at the output device 307.

The public transport vehicle control station 116 is shown in more detail in FIG. 4. The control station 116 includes a receiver 425, a processor 426, a memory 427, a transmitter 428, a control terminal 429 and a display 430. The receiver 425 receives the communications such as the communication 417 and decodes the communications. The information in them is stored in a database held in the memory 427. The information contained in each communication and retrieved by the control station 416 includes as well as the location information referred to earlier an identifier of the vehicle carrying the unit sending the communication, e.g. an identifier of the unit 414 for the communication 117. The processor 426 uses the identification and location information to produce a map of the current location of identified vehicles operating in the transport system and the map is displayed in graphical form on the display 430.

Personnel acting as control managers of the transport system can observe the displayed map on the display 430 to monitor that the vehicle movement is operating satisfactorily and can send and receive related communications at the control terminal 429. For example, if problems arise in the traffic flow involving public transport vehicles, the control manager is able to communicate with drivers of relevant vehicles by radio from the control terminal 429. Communications to or from the control terminal 429 are sent via the receiver 425 or transmitter 428 as appropriate. Thus, outgoing speech communications may be sent from the control terminal 429 to the unit 114 on the vehicle 101 via the receiver 425 and incoming speech communications may be sent via the transmitter 428 to the control terminal 429.

The communication system employed to send the vehicle identifier and location signals to the control station 116 and the traffic signal controller 113 may also be used to send communications (speech, data, pictures, video etc) to the command and communication units on the individual vehicles. Thus, the transmitter 425 of the control station 116 may be used to transmit speech or other information from a manager at the control terminal 429 to the receiver 302 included in the unit 114 on the vehicle 101 and conversely the transmitter 303 included in the unit 114 may be used to send speech or other information to the control terminal 429 via the receiver 424 (or directly if appropriate) The communication system employed and enhanced to provide the various operational functions described herein may be a trunked system designed to operate in accordance with TETRA (Terrestrial Trunked Radio) industry standards as defined by the European Telecommunications Standards Institute.

The vehicle control station 116 may also send out via the transmitter 415 a broadcast radio communication 131 (seen in FIG. 1) . This is picked up by each of the traffic light controller units such as the unit 113. In this way, information about the identity and current location of public transport vehicles may be provided.

The processors of the traffic light control units such as the processor 121 of the unit 113 are able to use this information to filter out unwanted communications from vehicles which are not approaching, such as, in the case of the unit 113, the communication 115 from the unit on board the vehicle 103.

The processor 426 of the vehicle control station 116 may also make determinations as to when the vehicle 101 is outside a zone controlled by any of the traffic signal or other local controllers such as the controller 113 and itself formulate and send via the transmitter 428 messages giving guidance or instruction relating to movement of the vehicle 101 using received regular information relating to current location of the vehicle.

Claims

1. A system for control of the movement of a vehicle including (i) a first communication unit on a vehicle operable to send and to receive radio communications, the unit being operable to send a communication including information about a current location of the vehicle; (ii) a controller including a second communication unit operable to send and receive radio communications, the second communication unit being operable to receive the communication from the first communication unit and to send to the first communication unit a communication including a guidance message relating to movement of the vehicle, characterised in that the controller is associated with a controlled traffic zone which the vehicle has to cross and the second communication unit is operable to send a communication including a guidance message relating to approach to the controlled zone by the vehicle.

2. A system according to claim 1 wherein the controller is operable to control an associated traffic signal controlling traffic flow across the controlled zone.

3. A system according to claim 2 wherein the second communication unit is operable to send communications including guidance messages relating to the speed of approach by the vehicle to the controlled zone to assist the vehicle to cross the controlled zone with minimum delay at the controlled zone.

4. A system according to claim 1, claim 2 or claim 3 wherein the guidance messages are instructions or advisory messages.

5. A system according to any one of the preceding claims, wherein the controller includes a processor operable to make decisions relating to movement of the vehicle and to issue guidance or instruction messages signals accordingly.

6. A system according to claim 5 wherein the controller also includes a memory in which is stored information relating to a planned movement of the vehicle and the processor is operable to make decisions using the stored information.

7. A system according to claim 6 wherein the memory has information stored therein relating to a planned route and/or a planned journey timetable of the vehicle.

8. A system according to any one of claims 5 to 7 wherein the processor is operable to estimate when the vehicle has reached a given distance from the controlled zone and to then to begin issuing guidance messages relating to the approach of the vehicle to the controlled zone.

9. A system according to any one of claims 5 to 8 wherein the processor is operable to detect when the vehicle has passed the zone controlled by the controller.

10. A system according to claim 9 wherein the processor is operable to detect when the vehicle has reached a given distance beyond the controlled zone and then to cease issuing guidance messages relating to movement of that vehicle.

11. A system according to any one of the preceding claims including a control station for controlling movement of vehicles, the control station having a third communication unit and being operable to send and receive radio communications.

12. A system according to claim 11 including a plurality of vehicles, each having thereon a communication unit, and a plurality of controllers each associated with one of a plurality of controlled zones, wherein the third communication unit of the control station is operable to receive communications from communication units on the vehicles and to send communications to such units.

13. A system according to claim 11 or claim 12, wherein the third communication unit is operable to receive communications from the communication units of the controllers.

14. A system according to claim 13 wherein the third communication unit is operable to send communications to the communication units of the controllers.

15. A system according to claim 14 wherein the third communication unit is operable to send communications including information which identifies the vehicles or their communication units and wherein processors of the controllers are operable to employ the information to filter signals from communication units on vehicles other than a vehicle or vehicles identified to be approaching a zone controlled by the controller.

16. A system according to any one of the preceding claims which provides communications between communication units in the system according to TETRA standards.

17. A system according to any one of claims 1 to 16 and substantially as herein described with reference to the accompanying drawings.

18. A method for control of the movement of a vehicle including (1) sending from a first communication unit on a vehicle radio communications including information about a current location of the vehicle; (ii) receiving by a second communication unit of a controller the communication from the first communication unit; and (iii) and sending from the second communication unit to the first communication unit a communication including a guidance message relating to movement of the vehicle; characterised in that the controller is associated with a controlled traffic zone which the vehicle has to cross and the second communication unit sends a communication including a guidance message relating to approach to the controlled zone by the vehicle.

19. A method according to claim 18 including also controlling a traffic signal by the controller to control traffic flow across the controlled zone.

20. A method according to claim 18 or claim 19 and substantially as herein described with reference to the accompanying drawings.

21. A controller for use in the system according to any one of claims 1 to 17 or in the method according to any one of claims 18 to 20, the controller including a communication unit operable to send and receive radio communications, the unit being operable to receive communication from the first communication unit on a vehicle and to send to the communication unit on the vehicle a communication including a guidance message relating to movement of the vehicle, characterised in that the controller is associated with a controlled traffic zone which the vehicle has to cross and the communication unit of the controller is operable to send a communication including a guidance message relating to approach to the controlled zone by the vehicle.

22. A controller according to claim 21, which is also operable to control a traffic signal to control traffic flow across the controlled zone

23. A controller according to claim 21 or claim 22, wherein the controller includes a processor operable to make decisions relating to movement of the vehicle and to issue instruction signals accordingly.

24. A controller according to any one of claims 21 to 23 wherein the controller also includes a memory in which is stored information relating to a planned movement of the vehicle and the processor is operable to make decisions using the stored information.

25. A controller according to claim 24 wherein the memory has information stored therein relating to a planned route and/or a planned journey timetable of the vehicle.

26. A controller according to any one of claims 21 to wherein the processor is operable to estimate when the vehicle has reached a given distance from the controlled zone and to then to begin issuing guidance messages relating to the approach of the vehicle to the controlled zone.

27. A controller according to any one of claims 21 to 26 wherein the processor is operable to detect when the vehicle has passed the controlled zone.

28. A controller according to claim 27 wherein the processor is operable to detect when the vehicle has passed the controlled zone and has reached a given distance from the controlled zone and then to cease issuing guidance messages relating to movement of that vehicle.

29. A controller according to any one of claims 21 to 28 and substantially as herein described with reference to FIG. 2 of the accompanying drawings.

30. A communication unit for mounting on a vehicle for use in the system according to any one of claims or in the method according to any one of claims 1 to 17 or in the method according to any one of claims 18 to 20, the communication unit being operable to transmit regular communications indicating a current location of the vehicle and to receive communications from a controller of a controlled traffic zone giving guidance on approach of the vehicle to the controlled zone.

31. A vehicle control station for use in a system according to any one of claims 11 to 17.

32. A vehicle control station according to claim 31, the control station having a communication unit operable to send radio communications to the communication units of vehicles and controllers of the system and to receive communications from the communication units of vehicles and controllers of the system.

33. A vehicle control station according to claim 31 or - claim 32 and substantially as herein described with reference to FIG. 4 of the accompanying drawings.