GB2345321A

GB2345321A - Vehicle heavy braking warning system

Info

Publication number: GB2345321A
Application number: GB9824563A
Authority: GB
Inventors: Matthew Snook
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-11-09
Filing date: 1998-11-09
Publication date: 2000-07-05
Also published as: GB9824563D0

Abstract

A vehicle heavy braking warning system comprises a vehicle management system 20 including means for measuring vehicular deceleration , and a warning signal means, associated with the management system, which is activated when the deceleration exceeds a preset value. The deceleration may be measured by sensing the rate of application of the brake pedal or the rate of change of brake pressure at 22, by an inertia switch, or by a sensor associated with the vehicle tachometer 28. The warning signal means may generate visible light e.g.at an additional rear lamp 23, or an ultrasonic signal, and the warning signal means may indicate the rate of braking of the vehicle. Different warning signals may be generated in dependence on the deceleration exceeding respective preset values, and the vehicle brakes may be automatically applied on receipt of an ultrasonic warning signal from another vehicle.

Description

VEHICLE HEAVY BRAKING WARNING SYSTEM The present invention relates to a vehicle heavy braking warning system, and in particular a system for assisting to prevent vehicular road accidents.

Present day vehicular road use is relatively high compared with ten or twenty years ago, and is projected to rise into the next century. The relatively high number of vehicles on the road networks is particularly noticeable during rush-hour periods, where some drivers tend to drive closer to the vehicle in front than the recommended stopping distance for the speed at which they are travelling. Typically these drivers rely on their reflexes, presumed driving ability and confidence in other drivers to avoid accidents caused by sudden braking of a vehicle in front.

The danger in a driver driving closer to the vehicle in front than the recommended stopping distance for that speed is increased by the driver's typical reaction to the illumination of a brake light in the vehicle in front.

The driver knows that the braking may be for a number of reasons, but principally two: firstly, it may be for hard braking, in which case he will need to take immediate evasive action. However, secondly, and more often than not, the brake is applied by the driver of the vehicle in front to ease the speed of the vehicle and thereby to adjust the distance between the vehicle in front and the vehicle in front of that. If the driver behind takes no immediate action to the brake light illumination, because he believes that the brake is being applied to ease speed slightly, it may then be too late to brake if the vehicle in front is in fact braking hard. If the driver behind had been travelling too close to the vehicle in front, the split-second delay in braking may be enough to cause a shunt-type accident.

In certain circumstances, particularly on motorways druing rush-hour, where a column of vehicles are each travelling too close to the vehicle in front, the shunt accident can be repeated so that a number of end- on-end collisions occur between more than two vehicles.

There have been a number of moves in the vehicle industry to reduce the number of vehicular shunts, the most obvious being the provision of an additional brake light in the vehicle back window sill. When a back window sill light is illuminated it can usually be seen through the windows of several vehicles by a driver behind, who is then able to take the appropriate action, and possibly avoid a vehicle shunt situation.

However, the provision of a rear window sill brake light does nothing to meet the problem that drivers may not react immediately to the illumination of a brake light in the vehicle in front. If the reality that drivers will continue to drive too close to the vehicle in front despite warnings to the contrary is accepted, there is a need in the art to reduce the number of vehicular shunt accidents caused as a result of this practice.

We have now devised a system whereby a driver travelling in a vehicle behind a vehicle in front may distinguish between heavy braking of the vehicle in front and light braking.

According to the present invention there is provided a vehicle heavy braking warning system, which system comprises: a vehicle management system including means for measuring the degree of vehicular deceleration; and a warning signal means associated with the vehicle management system, the arrangement being such that when the degree of vehicular deceleration measured by the vehicle management system exceeds a preset value, the warning signal means is activated.

By vehicle management system we mean a computer chip-based system which is responsible for controlling at least one function of the vehicle's operation. For example, the vehicle management system may control at least one of the vehicle ignition, the rate of fuel-injection or the response of the vehicle motor to activation of the vehicle accelerator.

The warning signal means is provided in addition to the conventional braking system comprising a set of brake lights. The warning signal means may be a rearwardly directed visible light producing arrangement, such as a light-bulb based unit, as with conventional braking systems. Preferably the light bulb-based unit may be placed in a position which is highly visible to drivers of the vehicles following the vehicle, for example on the rear window sill or built into the boot-door of the vehicle.

Alternatively, the warning signal may be some other form of electromagnetic radiation or wave form such as an ultrasonic signal. This ultrasonic signal may be detectable by a suitable ultrasonic receiver positioned at the front of the vehicle following. The ultrasonic signal received may be for automatically applying the brakes of the vehicle following, even if the driver of that vehicle has not applied them. The warning signal transmitter/receiver arrangement described above is a further aspect of the system according to the present invention.

The warning signal means may also indicate the degree of brake application. In its simplest form, the warning signal means only indicates if the rate of deceleration exceeds a certain preset value. In a preferred embodiment, the warning system means can indicate the degree of braking, wherein at least two brake light indicators, for example, are illuminated under heaving braking, whereas only one brake light indicator is illuminated under moderate braking. Light braking causes no warning signal and solely conventional brake light indicators will be lit.

The means for measuring the degree of vehicular declaration may be associated with the braking system itself, for example by measuring the rate of application of the brake either by providing a sensing arrangement at the pedal, for example, or by sensing the rate of change of pressure in the brake hydraulics. Alternatively, or in addition to the brake system associated means described above, the means for measuring the degree of vehicular deceleration may be associated with the vehicle tachometer.

In a preferred embodiment the means for measuring the degree of vehicular deceleration includes an inertia switch.

The degree of vehicular deceleration required before the warning signal means is activated will vary from vehicle to vehicle. The degree of deceleration required can be tested by road tests, for example recommended by parliament or by independent motor vehicle organisations.

The invention includes a kit for retro-fitting a system according to the invention. If the vehicle to be retro-fitted with the system already comprises a vehicle management system, the kit includes a means for measuring the degree of vehicular deceleration; and a warning signal means for connection to the vehicle management system. If, however, the vehicle tobe retro-fitted with the system of the invention does not include a vehicle management system, the kit includes a vehicle management system control box comprising a means for measuring the degree of vehicular deceleration; and a warning signal means for connection to the vehicle management system control box.

In order that the invention may be more fully understood, embodiments thereof will now be described by way of illustration only, wherein: Figure 1 is a schematic diagram of an embodiment acording to the present invention; and Figure 2 is a schematic diagram of an alternative embodiment in accordance with a system of the present invention.

The schematic of Figure 1 indicates the feedback loops operating in an embodiment of a system according to the present invention and will be self-explanatory to the skilled reader.

Referring to Fig. 2, there is shown a schematic of an embodiment of a vehicle braking system 10, having hydraulic linkages 12 connecting the individual brake arrangements 14 at each wheel 16 to a central unit 18 including a master cylinder. In this embodiment a vehicle management system 20 is connected to the brake system 10 so that when the brake pedal (not shown) is depressed, the conventional rearwardly facing brake lights are illuminated. In the system of the embodiment, the vehicle management system 20 is also connected to a sensor 22 which senses the rate of change of hydraulic pressure in the brake system 10. If the rate of change of hydraulic pressure in the brake system exceeds a certain level which level is pre-programmed into the vehicle management system 20, the rearwardly facing warning signal light 23 is illuminated in addition to the conventional brake lights 24.

In a further embodiment the vehicle management system 20 includes a sensor measuring deceleration 26, which sensor may be associated with the vehicle tachometer 28 or as a free-standing sensor, such as an inertia switch (not shown). A further embodiment includes the sensor measuring deceleration 26 only.

Claims

CLAIMS: . A vehicle heavy braking warning system, which system comprises: a vehicle management system including means for measuring the degree of vehicular deceleration ; and a warning signal means associated with the vehicle management system, the arrangement being such that when the degree of vehicular deceleration measured by the vehicle management system exceeds a preset value, the warning signal means is activated.

2. A system according to claim 1, wherein the waming signal means ger. erates an electromagnetic radiation or wave form.

3. A system according to claim 2, wherein the warning signal means generates visible light or an ultrasonic signal.

4. A system according to claim 1, 2 or 3. wherein the warning signal means indicates the rate of braking of the vehicle.

5. A system according to claim 4, wherein the vehicle management system is programme with at least two preset degrees of deceleration, whereby each preset generates a different warning signal.

6. A system according to any preceding claim, wherein the warning signal means is at least one lamp, the or each lamp generating visible light.

7. A system according to any preceding claim, wherein the means for measuring the degree of vehicular deceleration is associated with the vehicle brake system and/or the vehicle tachometer.

8. A system according to claim 7, wherein the brake system associated means for measuring the degree of vehicular deceleration senses the rate of Application of the brake at the brake pedal or senses the rate of change of pressure in the brake hydraulics.

9. A system according to any preceding claim, wherein the means for measuring the degree of vehicular deceleration includes an A system according to any preceding claim, wherein the system further comprises a warning signal receiver means associated with the vehicle management system for receiving warning signals from a warning signal means on canot., vehicle.

11. A system according to claim 10, wherein the vehicle management system automatically applies the vehicle brakes when the warning signal receiver means receives warning signals from another vehicle.

12. A kit for retro-fitting a system according to any of claims 1 to 9, which kit comprises a means for measuring the degree of vehicular deceleration ; and a warning signal means for connection to a vehicle management system.

13. A kit for retro-fitting a system according to any of claims 1 to 9, which kit comprises a vehicle management system control box including a means for measuring the degree of vehicular deceleration; and a warning signal means for connection to the vehicle management system control box.

14. A kit according to claim 12 or 13 further comprising a warning signal receiver means. A vehicle heavy braking warning system substantially as described herein with reference to the accompanying drawings.

16. A kit for retro-fitting a vehicle heavy braking warning system substantially as described herein.