WARNING SYSTEM FOR PREVENTING ROAD ACCIDENTS

Abstract: A warning system for preventing road accidents is provided and has a radio frequency transmitter (1) which emits a warning signal when a sensor (7, 8) detects sudden acceleration or deceleration or rolling over of a vehicle in which the transmitter (1) is mounted. The warning system also has a radio frequency receiver (2) to receive such a warning signal within a limited range, perhaps 1-2 kilometers, from the transmitter (1). The receiver (2) has means to emit an alerting signal to a driver of a vehicle in which the receiver is mounted and such an alerting signal is emitted after receipt of a warning signal. The alerting signal may be audible and if so the system may have an incoming signal acknowledge switch (15) to enable the driver to silence the signal.

Description: WARNING SYSTEM FOR PREVENTING ROAD ACCIDENTS This invention relates to a warning system for the prevention of road traffic accidents . Road accidents especially on motorways present a considerable danger to approaching traffic. Fixed warning panels on motorways are very infrequent, and warning cones and the like placed by the police are highly local to the incident and usually not posted until some time after it occurred. In conditions of poor visibility, due to fog or heavy rain for instance, such warning panels and cones may be virtually useless anyway. Even if drivers see the warnings they may not have time to respond before they find themselves party to an accident. My invention has the object of providing immediate warning of an accident over a useful radius, so that following motorists may be aware that a problem exists and slow down or if possible take a diversion. According to the invention there is a warning system for prevention of road traffic accidents, the system having a limited range transmitter and a receiver, each for mounting in motor vehicles, and a sensor for detection of ( a ) sudden acceleration or deceleration or (b) rolling over of a vehicle in which the transmitter is mounted, the transmitter being for omitting a warning signal when the sensor detects (a) and/or (b) and the receiver having means for emitting after receipt of such a warning signal an alerting signal to a driver of a vehicle in which the receiver is mounted. The receiver may and preferably will be in the same unit as the transmitter. All receivers and transmitters are on a given frequency (which may be a frequency associated with a given carriageway of a road) . An alerting signal from a receiver mounted in a vehicle will tell the driver that an accident has occurred in the vicinity so that he may take precautions. The alerting signal is preferably audible. A suitable range for the transmitters will be one to two kilometers. Each receiver may have the capacity to indicate whether it is approaching or receding from an operating transmitter. For example an indicator of signal strength, preferably a digital display may be visible to the driver. Further, such a display may calculate and give an approximate distance from the incident. The sensor associated with the transmitter may be any suitable type, but in particular may be a trembler- switch as used for car and other burglar-alarms (but set at a much lower sensitivity). Normally, an inertia switch will be used in detection of sudden acceleration or deceleration. There may well also be a tilt switch to sense if a vehicle has rolled over. Such switches will actuate the transmitter so that it emits a warning signal. The transmitter may have a manual switch to switch it on in the event for example of a mechanical breakdown causing the vehicle to obstruct a carriageway, or of another hazard such as an oil patch, a shed load or the like being observed. The transmitter may be linked in with a vehicle's hazard warning lights so that it emits a warning signal when these lights are switched on, for instance when the vehicle has broken down. A receiver connected to a motorway warning system would make it possible for warning signs to be activated as an additional safety measure. The system may be used in conjunction with or separate from a transmitter which emits, either continuously or periodically, a warning signal which is preferably receivable over a distance of less than 100 metres, this transmitter being suitable for carrying by a pedestrian, cyclist or other relatively inconspicuous road user. A receiver mounted in a vehicle would emit an alerting signal to the driver of the vehicle after receipt of such a warning signal. This alerting signal would preferably be different from the alerting signal emitted when a warning signal is received from another motor vehicle as a result of that other vehicle being involved in an accident. The following is an illustrative example of a warning system embodying the invention. Fig 1 is schematic circuit diagram of a warning system embodying the invention. A radio frequency transmitter 1 and a radio frequency receiver 2 are mounted in the same unit in a motor vehicle. Both the transmitter 1 and receiver 2 are connected to a single aerial with a transmit/receive switch 3. Warning signals are transmitted at a high frequency, over about 500 MHz, so that the aerial is under 200 mm in length. The system runs on power supplied by the battery 4 of the vehicle with a back-up, internal battery and charger 5 to provide power to the system when needed to allow transmission of a warning signal to continue for at least 20 minutes after an accident and when the main battery has failed. A main power on/off switch 6 enables the whole system to be turned off. Three switches 7,8,9 are connected to a microprocessor 10. Tilt switch 7 is to sense when the vehicle has rolled over. Inertia switch 8 is to sense sudden acceleration or deceleration of the vehicle. A manual test switch 9 is provided to enable the system to be tested. When the microprocessor with local memory 10 receives a signal from one or more of the switches 7,8,9 it actuates the radio frequency transmitter 1 via a transmit/receive control interface 11. The transmitter 1 will then within one second of actuation emit a warning signal which is a modulated signal with a type-coded tone burst of a duration less than one second. The intervals between bursts are random so as to tend to avoid interference between two transmitters actuated simultaneously. The range of this transmission is 1-2 kilometres. The radio frequency receiver 2 will pick up warning signals from transmitters within range. The receiver 2 is connected via a receiver audio interface 12 to the microprocessor 10. Receipt of a warning signal results in an alerting signal being emitted to the driver. In this embodiment, the alerting signal has a visual component provided by visual output 13 and an audible component provided by audio output 14. The warning system has an incoming signal acknowledge switch 15 to enable the driver to silence the alerting signal once he is aware of the warning. The receiver may further actuate the transmitter associated with it, for one or both of two purposes. One is to address the original transmitter to acknowledge reception of its signal and, optionally, increase the intervals between its transmissions. The other may be to "relay" the warning signal to further receivers. The illustrated warning system may be in conjunction with a separate transmitter 16 to be carried by a pedestrian, cyclist, horse rider or other person who is relatively inconspicuous on the road. This transmitter 16 emits a signal which may be picked up by receiver 2 over a range of about 100 metres. Transmitter 16 has a power on/off switch 17 so that the user is able to choose when a warning signal is to be emitted. Such transmitters 16 should generally only be used by road users in conditions of poor visibility or particular danger, and not all the time in town centres. An exception would be use by blind or other disabled people who are particularly vulnerable. Also a transmitter 16 may be placed at a temporary obstruction such as a skip or road works at a dangerous bend or in any situation where visibility is especially poor. The warning system should be mounted within a road vehicle securely so that it will be unlikely to break loose in an impact or roll-over and will withstand the maximum stress to be encountered in a collision. It may be supplied as original equipment in a new vehicle or retro-fitted to a vehicle of any age. The inertia switch may be a fuel cut-off inertia switch already installed in the vehicle.

Claims: CLAIMS 1. A warning system for prevention of road traffic accidents, the system having a limited range transmitter and a receiver, each for mounting in motor vehicles, and a sensor for detection of (a) sudden acceleration or deceleration or (b) rolling over of a vehicle in which the transmitter is mounted, the transmitter being for omitting a warning signal when the sensor detects (a) and/or (b) and the receiver having means for emitting after receipt of such a warning signal an alerting signal to a driver of a vehicle in which the receiver is mounted. 2. A warning system according to claim 1 wherein the alerting signal is audible. 3. A warning system according to claim 2 wherein there is a signal acknowledge switch to enable the driver to silence an audible alerting signal. 4. A warning system according to any one of claims 1 to 3 wherein the sensor is an inertia switch. 5. A warning system according to claim 4 wherein the inertia switch is a fuel cut-off switch of a vehicle. 6. A warning system according to claim 4 wherein the transmitter/receiver range is 1-2 kilometres.

Inventors: LOCHEAD RICHARD CHARLES KEARNE, LOCHEAD, RICHARD, CHARLES, KEARNEY
Applicants: LOCHEAD RICHARD CHARLES KEARNE, LOCHEAD, RICHARD, CHARLES, KEARNEY
Application year: 1991
Main classification: B60K28
IPC codes: B60K28, B60W30, G08G1