Vehicle security device

The present invention relates to a vehicle security device and method, particularly for the recovery of a stolen vehicle.

Vehicle immobilisers and/or alarm systems which aim to prevent a vehicle from being stolen are incorporated in most vehicles. Immobilisers typically use a code in the vehicle electronic start or ignition key which is recognised by a radio frequency identity ("RFID") loop around the lock barrel and then checked against the vehicle's engine control unit ("ECU"). If a current and valid code match is not found, the ECU prevents the vehicle engine from being started, for example by blocking fuel injections. Early immobilisers used static codes, but more recent immobilisers are rolling codes or cryptography to prevent code-copying from the key or ECU.

Advanced key systems and remote keyless systems allow a driver to open and/or start a vehicle without inserting a key into a lock barrel. The advanced key emits an encoded radio signal or an encoded infrared signal which is detected by a sensor on the vehicle before the vehicle is allowed to start. Other "key" systems include those which rely on fingerprint and/or eye (iris pattern) recognition.

Despite the advances in immobilising systems, vehicle theft is still a problem. One way that thieves bypass immobiliser security is to target vehicles which have already been started correctly and are running with a key in place, for example when a vehicle is stationary at traffic lights. Therefore, many vehicles are now fitted with a vehicle tracking system which allows a vehicle owner or a third party to track the location of the vehicle, and also optionally the speed and/or other vehicle information. Tracking systems may employ Global Positioning System (GPS) technology, Automatic Vehicle Location (AVL) technology, and/or a cellular transmitter to allow a third party to remotely identify the position of the vehicle.

The present invention provides an alternative device and method for improved vehicle recovery.

According to the first aspect of the invention, there is provided a vehicle key suppressor for inhibiting communication between an electronic start key and an engine control unit ("ECU") in a vehicle comprising a vehicle tracking system, in which the suppressor when activated by an activating signal from the tracking system sends an inhibitory signal which inhibits communication between the start key and the ECU, thereby preventing the vehicle engine from being started.

The invention there provides a way of inhibiting recognition by the ECU of the start key code. The suppressor comprises electronic circuitry so that when the suppressor is activated it sends an inhibitory signal. The inhibitory signal may suppress, interrupt, scramble and/or corrupt normal communication between the start key and the ECU. The inhibitor signal will thus prevent the vehicle engine from being started, for example by blocking fuel injection. The suppressor is used in combination with the vehicle tracking system, which activates the suppressor. This means that when the suppressor is activated and the vehicle is immobilised, it will be easier to locate the vehicle.

Several different frequencies are used for communication between the start key and the ECU. The suppressor may be programmed to inhibit any or all of these frequencies, for example by suppress, interrupt, scramble and/or corrupt the communication.

As used herein, the terms "electronic start key" and "start key" encompass conventional coded ignition keys as well as advanced key systems, remote keyless systems and fingerprint and/or eye recognition systems. The terms "engine control unit" ("ECU") is deemed to be synonymous with "engine management unit" ("EMU"), also known as a vehicle computer. The term "vehicle" encompasses cars and other terrestrial vehicles, as well as vehicles which travel in or on water, such as ships, and vehicles which travel in air, such as aeroplanes.

The suppressor may comprise a receptor means for receiving the activating signal from the tracking system. The suppressor may comprise a signal means operably linked to the receptor means for sending the inhibitory signal.

The tracking system may comprise a control means for receiving a control signal emitted by a tracking system control unit remote from the vehicle. The suppressor is therefore controlled by the tracking system control unit.

The tracking system may comprise an activating means operably linked to the control means for sending the activating signal to the suppressor in response to the control signal.

The suppressor may be deactivated when a deactivating signal is received from the tracking system. Here, a single activating signal may be required to activate the suppressor which will remain active until the deactivating signal is received.

Alternatively, the suppressor may be deactivated when the activating signal from the tracking system is stopped. Here, the activating signal may be a continuous signal from the tracking system which, when stopped, de-activates the suppressor.

The inhibitory signal from the suppressor in one embodiment does not stop the vehicle engine if it is running. For reasons of safety, for example, it may not be advisable to immobilise a vehicle if it is in motion. In this embodiment of the invention, the activated suppressor prevents the engine from being restarted after it is has been switched off.

Alternatively, using data from the vehicle tracking system, the suppressor may be activated or programmed to stop the vehicle engine when the vehicle is stationary.

The suppressor is in one aspect powered by a power supply to or from the tracking system.

The suppressor may provide a status signal to the tracking system, which in turn may communicate the status of the suppressor to the tracking system control unit.

The inhibitory signal emitted by the suppressor may be of ten milliwatts or less, to comply with MPT and ETS regulations. It may be adjusted lower than ten milliwatts on test to ensure that it does not affect other vehicles.

The inhibitory signal may comply with appropriate standard performance specifications, for example with United Kingdom or other national MPT regulations and/or European Telecommunications Standards ETS regulations.

The suppressor is directly linked to the tracking system. The suppressor may be easy to install either during manufacture of the vehicle or afterwards, for example in combination with installation of a tracking system.

The suppressor may be activatable only in response to the activating signal from the tracking system. In other words, the invention may be independent of systems which require the use of telephone signals such as mobile phone signals.

Also provided according to the present invention is a vehicle security system comprising a suppressor as defined herein.

Further provided is a vehicle comprising a suppressor as defined herein or a security system as defined herein.

In another aspect of the invention there is provided a method for recovering a vehicle comprising a suppressor as defined herein or a security system as defined herein, in which the method comprises the steps of activating the suppressor so that the vehicle engine is prevented from being restarted, locating the vehicle via the tracking system, and then recovering the vehicle.

Particular non-limiting examples of the present invention will now be described with reference to Fig. 1 which is a schematic view of a vehicle key suppressor.

When a vehicle fitted with a tracking system linked to a suppressor according to the present invention has been stolen the following actions could be taken.

An owner of the vehicle or the police notifies a tracking company responsible for the tracking system that the vehicle has been stolen. As shown schematically in Fig. 1 the tracking company sends a control signal (1) from their tracking system control unit to the tracker system (2) in the vehicle. The tracker system sends an activation signal via an activation communication link (3), for example a signal wire, to the suppressor (7). The suppressor then transmits an inhibitory signal (9) via an antenna (8) which scrambles and/or interrupts the standard signal (11) from the ignition key (10) to the EMU (12). The suppressor also sends an acknowledgment signal via a status communication link (4) to the tracker system, confirming that the suppressor has been activated, (5) is the power line from the tracker to the suppressor, (6) is the neutral line back to the tracker.

In one embodiment, the inhibitory signal transmitted by the suppressor does not stop the vehicle while it is running. However, the inhibitory signal would prevent the engine from being re-started as the standard signal from the ignition key would not be recognised by the EMU because it has been interrupted and/or scrambled by the activated suppressor.

The status of the suppressor is transmitted back to the tracker company through a status connection link (6) between the suppressor and the tracker system.

Once the vehicle has been immobilised by the suppressor - in the present embodiment when the vehicle has been stopped by the thief and is then prevented by the suppressor from being re-started - the tracker company can direct the owner and/or the police to recover the vehicle. Once the vehicle is recovered, the suppressor can be de-activated and normal vehicle operation resumed.

Although the present invention has been described with reference to preferred or exemplary embodiments, those skilled in the art will recognise that various modifications and variations to the same can be accomplished without departing from the spirit and scope of the present invention and that such modifications are clearly contemplated herein. No limitation with respect to the specific embodiments disclosed herein and set forth in the appended claims is intended nor should any be inferred.