GB2346244A

GB2346244A - Traffic information system for a vehicle

Info

Publication number: GB2346244A
Application number: GB9901295A
Authority: GB
Inventors: Graeme Peter Flynn
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1999-01-22
Filing date: 1999-01-22
Publication date: 2000-08-02
Also published as: GB9901295D0; EP1022704A1

Abstract

A traffic information system for a vehicle 10 is disclosed in which the vehicle 10 receives traffic information broadcasts from RDS-TMC and filters this information using signals from local transmitters A and B to define the vehicle's location. The vehicle location is determined using a look-up table in a memory in conjunction with an identity code included in the local signal from the transmitters A, B.

Description

2346244 A Traffic Information System for a Vehicle This invention relates

to traffic information systems for vehicles and in particular to a traffic information system in which a traffic information broadcast is filtered so as to provide to a user of the vehicle only information which is relevant to his local area.

It is known to provide traffic information broadcasts for vehicles using, for example, radio data system RDS and/or traffic management channel TMC technology. Such broadcasts include a location identifier which can be used to enable an on vehicle system to determine whether the information is relevant to the vehicle's current position (if known) and thereby to determine whether or not to broadcast the information to the vehicle user.

It is possible to use geopositional satellite GPS or cellphone triangulation as methods of achieving the necessary filtering but they are expensive systems and require extra equipment such as a GPS system or a 'phone in order to work. It is an object of this invention to provide an improved traffic information system.

According to the invention there is provided a traffic information system for a vehicle, the system comprising a controller arranged in use to receive a traffic information broadcast signal, wherein the controller is also arranged in use to receive a local signal which includes an identity code identifying an associated local signal transmitter, to determine the approximate current position of the vehicle from the identity code, and to filter traffic information from the broadcast signal such that only information relevant to the determined approximate current position of the vehicle is made available to a user.

The traffic information broadcast may be filtered using a look-up table which is programmed into a memory associated with the controller, the look-up table being arranged to relate said identity code to the location of its associated local transmitter and the controller being arranged to determine the approximate current location of the vehicle by monitoring which one or more local transmitters are in range.

The local transmitter may comprise a short range transmitter and the frequency of transmission of the local signal may be in the region of 433. 92 MHz.

The traffic information broadcast may comprise at least one of a radio data system broadcast (RDS) and a traffic management channel (TMQ broadcast.

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

Figure 1 is a schematic diagram of a vehicle including a traffic information system according to the invention; and Figure 2 is a plan view of the vehicle of Figure 1 in use.

Referring to the figures, a vehicle 10 comprises a receiver 12 which is arranged in use to receive traffic information broadcasts from a radio data system RDS and/or a traffic management channel TMC broadcast system.

The vehicle 10 further comprises a second receiver 14 which is arranged in use to receive signals from short range transmitters which transmit local information on, for example, 433.9Z MHz.

Both receivers 12, 14 supply the signals they receive to a controller 16 which is associated with a memory unit 18. The controller 16 is arranged to selectively broadcast traffic information (RDS-TMC) to a user of the vehicle 10 through at least one of a speaker 20 and a visual display unit 22.

The local transmitters A, B have a limited range within which their signals can be received. One example of such. transmitter technology is the "Traffic Master" system, although any local signal which can be received from a road and which has a short range and which includes an identity code would be suitable._ The identity codes of each transmitter A, B are programmed into a look-up table held in the memory 18.

When the vehicle 10 travels along a road 24 which passes through the range of the first transmitter A, the vehicle 10 receives signals from that transmitter A but is out of range of the other transmitter B which covers a different area such as an alternative road 26.

When the controller 16 receives a local signal from the first transmitter A through the receiver 14, it uses the identity code of the transmitter A to derive from the look-up table held in the memory 18 the approximate locality of the vehicle 10, i.e. by monitoring which one or more of the local transmitters A, B can be received.

The controller 16 uses this information about the vehicle's approximate location to filter the RDS-TMC traffic infoinlation broadcasts received through the receiver 12, so as to broadcast to the user, through the speaker 20 and/or display unit 22 only information which is relevant to the vehicle's location.

In this manner the user is provided with filtered traffic information broadcasts using location techniques which provide a significant 'cost saving over some known systems, such as those which use GPS for location.

Claims

-4. CLAIMS

1. A traffic information system for a vehicle, the system comprising a controller arranged in use to receive a traffic information broadcast signal, wherein the controller is also arranged in use receive a local signal which includes an identity code identifying an associated local signal transmitter, to determine the approximate current position of the vehicle from the identity code, and to filter traffic information from the broadcast signal such that only information relevant to the determined approximate current position of the vehicle is made available to a user.

2. A system according to Claim 1, wherein the traffic information broadcast is filtered using a look-up table which is programmed into a memory associated with the controller, the look-up table being arranged to relate said identity code to the location of its associated local transmitter and the controller being arranged to determine the approximate current location of the vehicle by monitoring which one or more local transmitters are in range.

3. A system according to Claim 1 or Claim 2, wherein the local transmitter comprises a short range transmitter.

4. A system according to Claim 3, wherein the frequency of transmission of the local signal is in the region of 433.92 MHz.

5. A system according to any preceding claim, the traffic information broadcast comprising at least-one of a radio data system broadcast (RDS) and a traffic management channel (TMC) broadcast.

6. A traffic information system for a vehicle substantially as described herein with reference to the accompanying drawings-