GB2331583A

GB2331583A - Vehicle automatic distance warning system

Info

Publication number: GB2331583A
Application number: GB9724452A
Authority: GB
Inventors: Thomas Wayne Richards
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-11-20
Filing date: 1997-11-20
Publication date: 1999-05-26
Also published as: GB2331583A9; GB9724452D0

Abstract

The system uses ultrasonic ranging sensors 2,3 mounted at the rear of a vehicle 6 to determine the distance to a following vehicle 7. The ABS wheel speed sensors of vehicle 6 are used to determine the speed of the vehicle and a warning is given to the driver of the following vehicle if he is driving too close having regard to the determined speed. The fog lights of the vehicle 6 may be used to give the warning. The system is disabled if the vehicle 6 is turning a corner as determined from signals from the ABS wheel speed sensors. Ranging sensors may also be provided at the front of vehicle 6 in which case the driver of vehicle 6 is warned when he is too close to a vehicle in front.

Description

2331583 1 AUTOMATIC DISTANCE WARNING SYSTEM This invention relates to an

automatic distance warning to the vehicle behind the car and for the driver of the said vehicle, with forward looking sensors, a waffling for the distance to vehicle ahead. It does this utilising some parts already fixed to the car. The system can also avoid errors when the vehicle turns by switching offthe system, utilising some parts already fixed to the car.

My invention solves the problem of most car drivers driving too close to the vehicle ahead. This results in accidents where the vehicles crash into each other, because not enough room is left between vehicles to stop safely, when an incident occurs. The vehicles would not crash into the vehicles in front if each driver left enough room to safely stop. My invention also solves the problem of error signals when the vehicle turns a comer e.t.c. The transducer waves can bounce off other things when the car turns a comer.

An object of this invention is to provide an automatic distance warning to the vehicle behind. It will warn the driver behind when he is too close, at what ever the speed the vehicles are going.

An object of this invention is to utilise what is already fitted to the vehicle, anti-lock brakes and rear fog lights, with an electronic module and sensors to provide an automatic distance warning system. Also to use the difference of the signals of the anti-lock brake sensors, when the car turns a corner, to switch offthe system so as not to have error signals.

Ultrasonics transducers may be used to find the distance because the system only has to update every one or two seconds. This means the ultrasonic waves are fast enough for this systems purpose. Electromagnetic waves can be used but may be more complicated.

Fig 1 shows: two cars driving and the front car bouncing waves off the car behind in order to work out its distance.

2 Fig 2 shows a graphical representation of the DC voltages that electronic module 4 derives from the anti-lock brake sensors and range finder sensors.

Fig 3 shows a graphical representation of the D.C. voltages from electronic module 4 when it makes fog lights 2 light up.

1 1 As shown in fig 1 there is car 6 driving and car 7 is following behind. On car 6 there is an antilock braking system which can produce a signal related to the speed of car 6. The anti-lock braking system can also switch offthe distance warning system when car 6 turns a corner. On the same axle the wheels of a car turn at a different speed when it turns. This difference of speed means that the anti-lock brake sensors will produce different signals when car 6 turns. This difference can be used by electronic module 4 to switch off system when car 6 turns.

The speed signal from the anti-lock brakes is used by electronic module 4 to produce a D C voltage which is related to the speed of the vehicle. Also on car 6 there are transducers 3 to bounce waves off car 7 and the time taken for the bounced waves to be recieved is related to the distance of car 7 behind car 6. Electronic module 4 uses this time delay to produce a D.C. voltage and then compares this voltage,%Nith D.C. voltage from anti-lock braking system. Thiscomparison of the two voltages then determines if fog lights 2 lights or not. The same system could be put on front of car 6 so that the driver of car 6 can be warned, audio or visually, that he is to close to the car in front. The only difference being that a warning light or sound would be in car 6 where the driver can see or hear it.

Fig 2 shows a graphical representation of the voltages in electronic module 4 to be compared, which only has to be done every one or two seconds. I have chosen, for the purpose of explination, 1 volt to equal 10 metres distance. 1 have chosen 1 volt to equal 10 m.p.h. Fig 2 shows when the fog fights 2 is not lit. 1 have taken 1 metre per 1 m.p.h. as a safe distance. 1 have chosen 7 volts as the range of the system because that is the U.K. speed limit. So 0 volts is 70 metres distance and the 7 volts is 0 metres. I have chosen for the speed 7 volts = 0 m.p.h. and 0 volts 70 m.p.h. In fig 2 the range finder 3 is at 2 volts = 50 metres distance and the anti-lock 3 brakes systems signal is at 4 volts = 30 m.p.h. This means that fog lights 2 is not lit because at 50 metres car 7 is well above the safe distance of 30 metres at 30 m.p.h.

Fig 3 is a graphical representation of the voltages when fog lights 2 are lit. The range finder is at 4 volts, which is 30 metres, and anti-lock system, 1, signal is at 3 volts which is 40 m.p.h. Fog fights 2 will light because 30 metres is too close, car 7 should be at least 40 metres behing car 6 to be a safe distance at 40 m.p.h. The fog lights 2 will stay lit until car 7,widens the gap to 40 metres or more or they both slow down to 30 m.p.h.

So far I have explained system for good dry conditions, when it rains a signal can be sent from the windscreen wipers, or outside temperature guage, to the electronic module 4 to alter the DC voltage signal for distance. This means that instead of 1 volt = 10 metres distance you can change it to say 1.5 volts = 10 metres. So fog lights 2 will light up at a slower speed and maintain a greater distance at whatever speed.

Under normal conditions fog lights 2 would be too bright so electronic module 4 will only light it partially, say 50%, or you can have two elements. When fog light 2 needs to be on electronic module 4 wHI only fight it partially, say 75%, and when a vehicle follows too close it will then light up to 100% as the warning.

4

Claims

1. An automatic distance warning system that uses parts already fitted to the car, anti-lock braking sensors and fog fights, which will automatically, at any speed, warn drivers behind that they are too close for safety.

2. A system as in claim 1 that will warn driver of car that he is too close to vehicle in front when transducers are looking forward.

3. A system as in claim 1 and 2 that is switched off when vehicle turns using the difference signal of anti-lock braking sensors on same axle.

A system as in claim 1 and 2 that can use ultrasonic transducers because it only has to update every one or two seconds.

5. A system as in claim 1 and 2 that uses an electronic comparator to compare voltage signals from the anti-lock braking sensors for speed and range finder for distance, to decide when to warn following vehicles when they are too close.

6. A system as in claim 1 and 2 that uses fog lights fitted to car to warn following vehicles when they are too close.