WO2014058297A1

WO2014058297A1 - An automatic vehicle braking system and a control method

Info

Publication number: WO2014058297A1
Application number: PCT/MY2013/000148
Authority: WO
Inventors: Woi Joon CHONG
Original assignee: Chong Woi Joon
Priority date: 2012-10-09
Filing date: 2013-08-19
Publication date: 2014-04-17

Abstract

The present invention relates to an automatic vehicle braking system for avoiding crash or collision and to mitigate the effects or severity of an imminent crash or collision to provide better safety. A processor automatically increases the brake force on the rear wheels and allows the rear wheels to be locked. This can improve the driver to steer better to avoid the leading obstacle and mitigate the severity of crash. If the measured relative distance decreases further lower than the second predefined threshold distance value, the processor will disable any braking method that will release the brake of own vehicle (ABS recycle braking process) and allow the wheels to be locked.

Description

Title : An Automatic Vehicle Braking System and A Control Method BACKGROUND

The present disclosure relates to an innovative vehicle braking system, which is able to achieve the optimum braking force of the particular vehicle when the driver is applying brakes to slow down the own vehicle within a short distance, when the leading obstacle is too close to our own vehicle. This is invented to overcome the weaknesses of current vehicle braking technologies, more specifically to Electronic Brakeforce Distribution (EBD) technology which tends to provide insufficient brake force on the rear wheels to slow down the own vehicle and ability to steer to avoid the leading obstacle, and Anti- lock Braking system ( also known as ABS system) which fails to achieve maximum braking force, within a short distance, to avoid crash/mitigate the severity of collision.

DESCRIPTION OF THE RELATED ART

Anti-lock Braking system ( ABS system) is ABS is an automobile safety system that allows the wheels on a vehicle to maintain tractive contact with the road surface, preventing the wheels from locking up (ceasing rotation) and avoiding uncontrolled skidding. ABS system is using static friction to slow down the vehicle. The purpose of ABS system invented is also to allow the own vehicle to be able to steer at all times. However, the main purpose of ABS is not to slow down the own vehicle within a short distance.

"Jones and Chirlders report Co-efficient of Friction. For good tyres on dry surfaces, there is not much difference between rolling(static) and sliding(kinetic) friction; and if you back off the braking force very much, you will get less braking than if you just locked them down."

"In an ABS-equipped vehicle, you'll feel a pulsating in the brake pedal during hard stops, or if the vehicle loses traction. This is perfectly normal, as the brake system is pumping the brakes for you, freeing up any locked wheel and leaving you in control of the vehicle. There's nothing wrong with the pulsating brakes. Don't release them because the car is doing the work for you" [source: http://www.familycar.com/brakes.htm1.

"When you step on the brake pedal, you are actually pushing against a plunger in the master cylinder, which forces hydraulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel." [source: http://www.familycar.com/brakes.htmll In another word, if your brake pedal is being pumped up, the braking efficiency for all the wheels is either stay or even lesser. When one of your wheels has inadequate tyre threads or on the slippery side such as the road plaint or water, it becomes very easy for that particular wheel to be locked up. When this wheel is locked up and the brake pedal will being pumped up, the brake pressure for the rest of the wheels will not increase, they will just stay as it is or even reduced. In another words; the rest of the wheels may not be able to achieve high level of brake efficiently. In this new braking method, it can ensure that all wheels have achieved 100% brake efficiency and maintain high- level of brake efficiency for a short distance (combination of static and kinetic friction). An example of that is shown on FIGURE 3, when the right front wheel has been locked up easily ( due to maybe slippery road paint and inadequate tyre thread), it achieves 100% of brake efficiency, but the left front wheel may only achieve 70% brake efficiency and the rear wheels will achieve even lower brake efficiency due to Electronic Brake Distribution (EBD) system, the conventional brake system will pump your brake pedal to release the brake pressure on the locked front right wheel when the brake pressure on the other wheels will stay or even reduced. This system is to ensure that the own vehicle does not skid and able to steer. However, If the leading obstacle is too close and crash is inevitable, steering away from leading obstacle may not likely to mitigate the severity of crash, the driver should be trying to achieve maximum brake force to avoid mitigate the crash. So, in this new braking method, before crashing into the leading obstacle, we do not release the brake pressure anymore, and allow the left side of front wheels and rear wheels to achieve 100% of brake efficiency and maintain high level of braking efficiency for a short distance, when the driver step firmly on the pedal brake. This braking method has taken into consideration of controllability and ability to steer.

"The ABS controller monitors the speed sensors at all times, it is looking for decelerations in the wheel that are out of the ordinary. As it knows that a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration". One of the weakest of ABS is unable to maintain braking force after the crash has happened. At the moment of crash, all the wheels will decelerate out of the ordinary. ABS will immediately release the braking pressure on the wheels, which results in serious crash and damages. The momentum of crash will continue to kill the driver, but the braking force has been vanished at the moment the crash. The distance from point of crash to the driver is approximately 1.5 meter, and to the back passengers is 2.5 meter. In an accident, this distance of braking force can have big effects to rescue many lives.

The Insurance Institute for Highway Safety (IIHS) has conducted several studies trying to determine if cars equipped with ABS are involved in more or fewer fatal accidents. It turns out that in a 1996 study, vehicles equipped with ABS were overall no less likely to be involved in fatal accidents than vehicles without. The study actually stated that although cars with ABS were less likely to be involved in accidents fatal to the occupants of other cars, they are more likely to be involved in accidents fatal to the occupants of the ABS car, especially single-vehicle accidents. This explains why more fatal accidents have occurred to the occupants of the ABS car, because the braking effect vanishes at the moment of crash.

Video in Youtube, namely "ABS vs. No ABS - Episode 4" and " the difference between ABS and non-ABS emergency braking" have shown that ABS will leave a skid mark on the road, skid mark is the mark of locking wheel. It indicates that ABS will unlock the wheels when it detects that the wheels of a vehicle have been locked up. Based on the skid marks that have been left behind by ABS and the pump up of brake pedal, driver needs to step again firmly on the pedal brake to perform the brake cycle of 0% to 100 (leaving the skid mark) for the particular wheel. The distance between 2 skid marks can be 1 meter away.

"ABS Brake recycle process" is defined as once the ABS system detects that a wheel of a vehicle has been locked up, it will immediately release the brake pressure put on that wheel by pumping up the pedal brake of the own vehicle ( that why the driver's leg can feel the pulsing in the brake pedal when the wheels are locked up). This comes from the rapid opening and closing of the valves. This procedure is required in order for the wheel to rotate again. In order to continue to brake the own vehicle, driver will need to step firmly again on the pedal brake. In another words, the brake cycle starts again, and brake force for the wheel may start from 0% to 100%. "A higher coefficient of friction decreases your stopping distance". The Graph A of brake cycle is illustrated above. Before the wheels are locked up, the own vehicle is slowed down with static friction. As explained earlier, when the ABS system detected that the wheel has been locked up, it will automatically pumped up the pedal brake, the driver will need to step firmly again on the pedal brake to slow the own vehicle. This means that the own vehicle may need to go through another braking process which start from 0 - 100%. In this new braking method, if the leading obstacle is too close, this braking system will use kinetic friction to slow the vehicle, i.e. locking the wheels of own vehicle. In the Graph A, the braking efficiency is at high level for a moment when the wheel has been locked up. The combination of static friction and kinetic friction can generate higher coefficient of friction for a short moment, which can kill the speed of the own vehicle in short distance, to avoid crash or mitigate the severity of crash. This new braking method have also taken into consideration of controllability (skidding wheel) and ability to steer of the own vehicle.

For many existing tyres, the coefficient of kinetic friction on a dry road surface may approach 80% of braking effectiveness if the braking is not prolonged as to cause tire melting.

In the Graph A, when the wheels of vehicle are locked up, the braking efficiency can be assured at high level (at 80-90%) for a short moment. But, if we release the brakes (caused by ABS system), our brake efficiency will need start from 0% again. So, if the leading obstacle is too close to own vehicle, and ABS system will cause the brake force to start from 0% again, it is not going to slow down the own vehicle faster. This new braking system will slow down the vehicle with kinetic friction (keep the wheels being locked up) (constantly achieving high level of braking efficiency), instead of start the braking cycle from 0% again before clashing into the leading obstacle. This new braking method has also taked into consideration of other factors such as maintaining small amount of skid and ability to steer.

The factors that can increase the distance of brake cycle from 0-100% are many, including the tyre threads, road surface, wear and tear of brake system, and strength for the driver to step hardly again on the pedal brake. All these factors can increase substantially the distance for the brake to achieve 100% efficiency.

The maximum braking force is generated when the tire and road surface begin to slip. All the drivers/machine are attempting to achieve the maximum braking force before a crash. So the nearer the leading obstacle to the own vehicle, the harder for an ordinary driver to step harder on the pedal brake in order to achieve maximum braking force. However, there is no definite answer as to when the maximum braking force is generated. So, the wheels of vehicle tend to lock up after the driver has firmly stepped on the pedal brake, especially when the leading obstacles is getting closer to the own vehicle. ABS recycle process method will cause the particular locked wheel to go through 0% brake process and insufficient brake force on other wheels. Electronic brakeforce distribution ( EBD ) is an automobile brake technology that automatically varies the amount of force applied to each of a vehicle's brakes based on road conditions, speed, loading, etc. Always coupled with anti-lock braking systems, EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining vehicular control. Typically, the front end carries the most weight and EBD distributes less braking pressure to the rear brakes so the rear brakes do not lock up and cause a skid.

However, if there is a leading obstacle too close to own vehicle, more brake pressure should also be put to rear wheels in order to achieve bigger braking force. This new braking method also allows reasonable small amount of skid ( i.e. rear wheels are locked up for short distance) as it can avoid the ABS braking cycle of 0% -100% as described before. Allowing reasonable small amount of skid for own vehicle not only can generate more braking force to slow the own vehicle before clashing into the leading obstacle, it can also improve steering ability of the own vehicle, so that it can have better chances to avoid the leading obstacles.

Pedal brakes ( Foot brake) may be broadly categorized as a form of friction brakes, pump brakes, and electromagnetic brakes. Friction ( pad/shoe) brakes are the most commonly used brakes and typically include rotating devices which employ a stationary pad and a roatating wear surface.

Hand brake ( emergency brake, e-brake, parking brake ) is a form of latching brake usually used to keep the car stationary. It operates mostly on the rear wheels. Although stopping force provided by using the handbrake is small, but would still aid in slow down the vehicle. By using it, it will likely initiate a rear wheel skid. The handbrake was initially intended for use in case of mechanical failure where the regular footbrake is inoperable and compromised.

Multiple patents including Patent US 7,729,840, US 6,203,122, US 5,167,441, US 6,940,448 disclose vehicle braking method and device for ascertaining the imminence of an unavoidable collision.

The above mentioned prior arts merely disclose braking techonologies, which are basically operated using only pedal brakes with ABS and ECT system. The existing automatic braking systems are effective and provide safety when the distance between two vehicles is considerable. However, if the distance between the own vehicle and another vehicle or an obstacle narrows considerably, the braking techonologies such as ABS and EBD do not provide much help and mostly leads to accidents still. The vehicle braking system proposed here is more effective and provide better safety as it can help the driver by increasing brake force if the distance with the leading obstacle is too close. SUMMARY

In view of the foregoing, the present disclosure relates to a vehicle braking system which can increase the brake force of the rear wheels of a vehicle and prevent any brake system (such as ABS system) from releasing the brake force and increase brake pressure on other wheels when the own vehicle is being braked either by machine or manually by human (hereinafter refer to "driver") to slow the own vehicle to avoid a crash or collision or to mitigate the effects or severity of an imminent crash or collision, while taking ABS recycle brake process, controllability (wheel skid) and ability to steer of the own vehicle, and the situation whereby an ordinary driver will apply full brake force to slow down the own vehicle into consideration.

In the present disclosure, the vehicle braking system comprises of sensor detecting that the driver is applying brake to slow down the own vehicle, and then the sensors present at the front end of the own vehicle that detects signals of the relative distance between the own vehicle and another vehicle or obstacle while measuring the speed of the own vehicle and the leading vehicle, if the relative distance between the own vehicle and other vehicle or obstacle calculated by the processor, after measuring the speed of own vehicle and the leading vehicle, based on the sensor signals received, is lower than the first predefined threshold distance value, the processor automatically increase the brakes force on the rear wheels , and also allow the driver to lock up the rear wheels of the own vehicle while allowing the own vehicle to be steered away from the leading vehicle or obstacle while slowing down.

The first threshold distance value is determined based on following three factors. Usually, the shortest distance of the following three factors from the leading obstacle shall be the first threshold distance value, based on the speeds of the own vehicle and the leading vehicle.

1.) It is the distance where maximum brake force can be achieved. The maximum brake force is calculated based on combination of coefficient of static friction and kinetic friction based on the speed of own vehicle, assuming that the driver has applied full brake force to slow down the own vehicle. As shown in FIGURE 4, as the ABS braking method is using static friction to slow down the vehicle, it will automatically release the brake pressure of the locked wheel in order to brake again with static friction. However, If the leading obstacle is too close to the own vehicle (Vehicle Clashing Point), releasing the brake may start the braking force from 0% which mean that It will create more severity and damages. So, in this braking method, if the leading obstacle is too close to our own vehicle (Vehicle Clashing Point) based on the speed of the own vehicle, it will allow the own vehicle to use kinetic friction to slow down the vehicle. This can ensure the maximum brake force can be achieved, within a short distance, to avoid crash or collision or mitigate the effects and severity of the crash or collision. 2. ) It is the distance where the own vehicle does not substantially away from its route ( allow reasonable small amount of skid). Many methods can be used to ensure the own vehicle does not substantially away from its route, 1) when the own vehicle skids away from its route substantially ( sometimes it is because the driver has steered away from the leading obstacle), the distance sensor will not be able to detect the leading obstacle. The increased brake force will be uplifted, the locked wheels, if any, will be released. 2) the lock up of the rear wheels have been predefined, not exceeding certain meters, eg. 3 meter,

3. ) It is the distance or situation where ordinary driver will apply full brake pressure (step firmly on the pedal brake) to avoid/mitigate severity and damages from crashing into the leading obstacles based on the speed of the own vehicle and the leading vehicle. This is also configurable by the driver or the vehicle manufacturer.

When the relative distance between the own vehicle and the leading vehicle or obstacle further decreases lower than the second predefined threshold distance value, any brake system of the own vehicle that will release the brake ( such as ABS system, etc) will be disabled in order to allow the driver to lock the front wheels to achieve maximum braking force to slow down the own vehicle before crashing into the leading vehicle. This is to prevent any brake system such as ABS systems, etc to cause the particular wheel from going through the ABS recycle process again which is to start the brake from 0% to 100% and ensure that the brake pressure on the other wheels to achieve high level of brake efficiency.

The second threshold distance value is determined based on a distance where a crash or collision is not likely be avoided and/or the effects or severity of the irrirninent crash will not likely be mitigated by steering the own vehicle away from the leading vehicle or obstacle.

It must be further explained here that when a vehicle is being steered away, the brake force for the vehicle will be reduced. As such, when it is unlikely that crash can be mitigated by steering away^'from the leading obstacle, the front wheels should be locked to achieve bigger brake force to slow down the vehicle, instead of allowing the nervous driver to steer, which give lower brake force.

The present disclosure relates to a vehicle braking method wherein the method comprises of the following steps : detecting whether the driver is applying brake to slow the own vehicle, measuring the relative distance between the own vehicle and a leading vehicle or an obstacle using one or more distance measuring sensors positioned on the own vehicle; measuring the speed of the own vehicle and the leading vehicle; sending the measured relative distance and speed to a processor also positioned on the own vehicle; and compare it with the predefined threshold distances values. When the distance sensor has detected that a leading obstacle is within the first threshold distance, the processor will increase the brake force on the rear wheels and allows the rear wheels to be locked up by the driver/machine.

If the relative distance calculated by the processor further decreases lower than the second predefined threshold distance value, the front wheels are also allowed to locked up by the driver. It is to prevent any brake system (such as ABS system) to unlock the wheels which result in ABS recycle brake process for the locked wheel and ensure high level of brake efficiency achieved by other wheels for a short moment to avoid/mitigate the crash.

Brief description of drawing

The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the following descriptions and accompanying drawings. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scopes of the embodiments herein.

Figure 1 illustrates an automatic vehicle braking system 100 which comprises of a brake activation sensor 106, one or more distance and speed measuring sensors 102, a processor 104, deactivating ABS brake system device 114, speed sensor 112, all configured and positioned on the own vehicle 108. In an embodiment, the sensors 102 are positioned on the front side of the own vehicle 108, wherein the sensors 102 receives signals of a leading vehicle or obstacle 110. In an embodiment, the sensors 102 can be positioned at the two front corners of the own vehicle 108. In another embodiment, the sensors 102 can be positioned at the center of the front of the own vehicle 108. A person ordinarily skilled in the art can understand that the positioning of the sensors 102 can be done on various front ends of the own vehicle 108 to receive signals of a leading vehicle or obstacle 110.

The processor 104 receives signal from the brake activation sensor 106, and understand that the driver is braking the own vehicle to slow down the own vehicle. The processor 104 sends commands to distance and speed measuring sensors 102 to receive the relative distance between the own vehicle 108 and the leading vehicle or obstacle 110, dl, and measures the speed of the own vehicle received from speed sensor 112 and the leading obstacle. Based on the speed of the own vehicle and the leading vehicle, the processor compare the relative distance, dl, with the predefined threshold distance value. If the distance,dl fall below first threshold distance value, the processor will increase the brake force on the rear wheels and allow driver to lock up the rear wheels. If the relative distance, dl measured by distance measuring sensor 102 further decreases lower than the second predefined threshold distance value, ( where a crash or collision is not likely be avoided and/or the effects or severity of the imminent crash or collision will not likely be mitigated by steering the own vehicle away from the leading vehicle or obstacle), the processor will also allow the front wheels to be locked up (not letting any brake system to release the brake). For instance, when the processor 104 receives signal from brake activation sensor 106 (indicating that the driver is braking the own vehicle to slow down the own vehicle), the processor 104 sends command to distance and speed measuring sensors 102 to receive the relative distance between the own vehicle 108 and the leading vehicle or obstacle 110, and measure the speed of the own vehicle through speed sensor 112. If the distance value, dl, is 3 meter and the speed of own vehicle is 80kmph. Based on the speed of 80kmph, the processor recognized that the first threshold distance value is 4 meter from the predefined threshold distance values. As the distance value, dl of 3 meter is below than the first threshold distance value of 4 meter, the processor will increase the brake force on the rear wheels and allows the driver to lock the rear wheels. When the distance value, dl, measured by distance sensors 102 is further drop to 1 meter, which is the second predefined threshold distance value, the processor 104 will send command to deactivating ABS brake system device,114, which is to deactivate any braking system that will release the brake pressure after the driver has locked the wheels of own vehicle and allow all the wheels be locked up by the driver.

In an embodiment, the threshold distance values can be pre-set by the vehicle manufacturers and/or can be customized or configured by the driver of the own vehicle 108 based on the time it takes to achieve the own vehicle 108's optimum braking force as well as the controllability and steering ability of the own vehicle.

In another embodiment, the automatic vehicle braking system 100 can comprise of one or a combination of distance sensors 102 and speed sensors 112.

In a further embodiment, once the measured relative distance between the own vehicle 108 and a leading vehicle or obstacle 110, dl is no longer lower than the predefined threshold distance values, the automatic vehicle braking system, 100 will be immediately deactivated.

Figure 2 illustates an automatic vehicle braking method 200, disclosing the steps for vehicle braking system 100 as described above. At step 202, a brake activation sensor to detect whether the driver is applying brake to slow down the own vehicle. At step 204, one or more distance measuring sensors 102, positioned at the front end of the own vehicle 108 measure the relative distance between the own vehicle 108 and a leading vehicle or obstacle 110, dl. At step 206, one or more speed measuring sensors 112, also positioned on the own vehicle 108 measure the relative speed of the own vehicle 108 and the leading vehicle 110. At step 208, a processor 104 calculates and compares the measured relative distance between the own vehicle 108 and the leading vehicle or obstacle 110, dl, taking into account the measured relative speed of the own vehicle 108 and the leading vehicle 110. At step 210, if the measured relative distance, dl is lower than the first predefined threshold distance value, the processor 104 automatically increases the brake pressure on the rear wheels and allow the driver to lock the rear wheels of the own vehicle 108 to slow down the own vehicle 108, while still allowing the own vehicle 108 to be steered away from the leading vehicle or obstacle 110 while slowing down. At step 212, if the measured relative distance, dl decreases lower than the second predefined value, ( where a crash or collision is not likely to be avoided and/or the effects or severity of the imminent crash or collision will not be mitigated by steering the own vehicle 108 away from the leading vehicle or obstacle 110), the processor 104 automatically disable any braking method that will release the brake of the own vehicle, such as ABS braking system and allow all the wheels be locked up by the driver.

It will of cause be realized that the present disclosure has been given only by way illustrative examples of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth.

Claims

Claims:-

1. A vehicle braking system comprising:

A plurality of distance measuring sensors for measuring the relative distance between the own vehicle and a leading obstacle.

A processor for receiving the said relative distance measured by the said distance measuring sensors and comparing the said measured relative distance with the predefined threshold distance values, allow the wheels of the own vehicle to be locked up.

2. The vehicle braking system of claim 1, wherein the said leading obstacle comprises of another vehicle, and any living and/or non-living obstacle.

3. The vehicle braking system of claim 1, wherein the driver comprises of machine or human being that are operating the own vehicle.

4. The vehicle braking system of claim 1, wherein the said processor can automatically increase the brake pressure on the rear wheels.

5. The vehicle braking system of claim 1, wherein the said processor allows the rear wheels to be locked up.

6. The vehicle braking system of claim 1, wherein a plurality of sensor for detecting the driver is applying brake to slow down the own vehicle,

7. The vehicle braking system of claim 1, wherein the said processor automatically disable any brake system such as ABS system that will release the brake pressure of the own vehicle. This can allow the wheels of the own vehicle to be locked up.

8. The vehicle braking system of claim 1, wherein the said system further comprises of one or more speed measuring sensors, wherein the said speed measuring sensors measure the relative speed between the said own vehicle and the said leading obstacle, wherein the said processor automatically allow the wheels of the own vehicle to be locked up.

9. A vehicle braking method comprising of, but not limited to the steps of :

a. A plurality of sensor for detecting the driver is applying brake to slow down the own vehicle,

b. Measuring the relative distance between the own vehicle and the leading vehicle using one or more distance measuring sensors;

c. Measuring the speed of the own. vehicle and the leading vehicle using one or more speed measuring sensors;

d. Comparing the said measured relative distance with the predefined threshold distance value(s), while taking into consideration the measured relative speed; and

e. Automatically increase the brake pressure on the rear wheels and allow the rear wheels to be locked, while still allowing the own vehicle to be steered away from the leading vehicle or obstacle while slowing down if the measured relative distance is lower than the first predefined threshold distance value.

10. An automatic vehicle braking method comprising the further steps of, but not limited to:

c. Measuring the relative speed of the own vehicle and the leading vehicle using one or more speed measuring sensors;

e. Automatically disable any braking methods such as ABS system, etc that will release the brake force of any wheel of own vehicle when the wheel is locked up, if the said measured relative distance further decreases lower than the second predefined threshold distance value. This can allow the front wheels to be locked up,.

11. The method of claim 9 and 10 are maintained during the crash as long as the driver is still applying the brake to slow down the vehicle.

12. Once the measured relative distance between the own vehicle and the leading obstacle is no longer lower than the predefined threshold distance values, the vehicle braking system will be deactivated, and let the own vehicle back to its original braking method.

13. The braking effects of own vehicle are maintained and continue to be action even during and after a crash or collision.

14. The method of claim 9, wherein the first threshold distance value is predefined by the vehicle manufacturer. It can be based on the distance where maximum brake force can be achieved assuming that the driver has applied full brake force to slow down the vehicle at certain vehicle speed. The maximum brake force is calculated by combination of coefficient of static friction and kinetic friction. So, in this braking method, if the leading obstacle is too close to our own vehicle based on the speed of the own vehicle and the leading obstacle, it allows the driver to use kinetic friction to slow down the vehicle. This can ensure the maximum brake force can be achieved, within a short distance, to avoid crash or collision or mitigate the effects and severity of the crash or collision.

15. The method of claim 9, wherein the said first threshold distance value is predefined by the vehicle manufacturer, so that the said own vehicle does not substantially depart from its original route. In another words, it allows reasonable small amount of skid.

16. The method of claim 9, wherein the said first threshold distance value is predefined by the vehicle manufacturer, wherein it is a situation where an ordinary driver will step firmly On pedal brake to avoid/mitigate severity and damages from crashing into the leading obstacles based on the speed of the own vehicle and the leading vehicle.

17. The method of claim 9, wherein the said first threshold distance is predefined by the vehicle manufacturer, based also on the controllability and steering ability of the own vehicle.

18. The method of claim 10, wherein the ability to steer the said own vehicle is disabled where a crash or collision is not likely be avoided and/or the effects or severity of the imminent crash or collision is not likely to be mitigated by steering the own vehicle away from the leading vehicle or obstacle.

19. The method of Claim 9 and 10, wherein the said first and second threshold distance values are predefined by the vehicle manufacturer, based on the speed of the vehicle and the leading vehicle as well as the relative distance between the own vehicle and the leading vehicle, wherein an ordinary driver would have stepped firmly on the pedal brakes to avoid crashing or colliding into the leading vehicle but it is almost impossible for the driver of the own vehicle to react, while taking into account the controllability and steering ability of the own vehicle.

20. The method of Claim 9 and 10, wherein the said first and second threshold distance values are configurable by the driver or the vehicle manufacturer.