DE102016213756A1 - Method and device for safe operation of a motor vehicle - Google Patents

Abstract

The invention relates to a method for safe operation of a motor vehicle, wherein it is determined by means of a collision detection device, whether a collision of the motor vehicle with a collision object is imminent and on detection of an imminent collision Bremsassistenzzeinrichtung for executing an emergency braking of the motor vehicle is activated and a steering assistance device to support a leader of the motor vehicle in an emergency avoidance maneuver by applying a steering torque to a steering device of the motor vehicle, as soon as it begins to steer is activated. The steering assistance by the steering assistance device is provided in advance of the execution of the emergency braking by the Bremsassistzeinrichtung, wherein the Bremsassistzeinrichtung automatically performs an emergency braking of the motor vehicle as a result of their activation after the steering assistance device has applied a steering torque after its activation at the steering device. The invention also relates to a method implementing safety device for safe operation of a motor vehicle.

Description

The present invention relates to a method for safe operation of a motor vehicle according to the preamble of claim 1. In this case, it is determined by means of a collision detection device, whether a collision of the motor vehicle with a collision object is imminent. When an imminent collision is detected, a brake assistance device is activated to execute emergency braking of the motor vehicle. Furthermore, a steering assistance device is activated to support a driver of the motor vehicle by applying a steering torque to a steering device of the motor vehicle as soon as it begins to steer. The invention further relates to an associated safety device for carrying out the method.

Active safety is one of the focal points in the development of current and future vehicle systems. A well-known system in the field of active safety, that is, for accident prevention, for example, the electronic stability program (ESP) for vehicle stabilization by braking intervention in the driving dynamics border area.

In addition to systems for vehicle stabilization and warning systems for visual and / or audible warning of a driver of the motor vehicle in the event of impending collision (also known as FCW - Forward Collision Warning - called) and brake assistance systems for triggering an emergency braking are known (for example, AEB - Autonomous Emergency Braking), automatically intervene upon detection of a risk of collision of the motor vehicle with a collision object, for example, based on an environment detection by means of radar and / or video sensors and autonomously decelerate the motor vehicle.

Furthermore, systems for assisting a driver of the motor vehicle in an emergency avoidance maneuver by applying a steering torque to a steering device of the motor vehicle when it begins to steer itself known (for example ESA - Emergency Steering Assist).

It has been shown that average drivers in dangerous situations often have problems to avoid an obstacle by appropriate steering maneuvers. Thus, for example, too late, too fast or too slow, too much or too little or not steered and countersteering, for example, when changing lanes, wrong or not executed. This leads either to a collision with the collision object or to an instability, for example to spin, of the motor vehicle.

• 1) Zuerst wird der Führer des Kraftfahrzeugs bei einer drohenden Kollision mit einem Kollisionsobjekt optisch und/oder akustisch mittels einer entsprechenden Warneinrichtung, zum Beispiel FCW, gewarnt.
• 2) Anschließend, das heißt bei Erreichen eines für eine Notbremsung des Kraftfahrzeugs kritischen Abstands zum Kollisionsobjekt (Kritikalität), führt die (Not-)Bremsassistenzeinrichtung (AEB) eine selbsttätige Notbremsung des Kraftfahrzeugs durch.
• 3) Daraufhin erst stellt die Lenkunterstützungseinrichtung (ESA) dem Führer des Kraftfahrzeugs die Lenkunterstützung zum Durchführen eines Ausweichmanövers durch Aufbringen eines Lenkmoments an der Lenkeinrichtung des Kraftfahrzeugs bereit, sobald der Führer des Kraftfahrzeugs lenkt, um die Kollision mit dem Kollisionsobjekt zu vermeiden.

In the case of motor vehicles on the market today equipped with FCW, AEB and ESA systems, the following actions will always be taken in a specified sequence, in the event of an imminent collision with a collision object:

• 1) First, the driver of the motor vehicle in a threatening collision with a collision object visually and / or acoustically by means of a corresponding warning device, for example FCW, warned.
• 2) Subsequently, that is, upon reaching a critical for an emergency braking of the motor vehicle distance to the collision object (criticality), the (emergency) Bremsassistzeinrichtung (AEB) performs an automatic emergency braking of the motor vehicle.
• 3) Next, the steering assist device (ESA) provides the driver of the motor vehicle with steering assistance to perform an evasive maneuver by applying a steering torque to the steering device of the motor vehicle as soon as the driver of the motor vehicle steers to avoid the collision with the collision object.

This sequence is essentially based on the fact that, depending on the quality of the environment detection sensors (for example radar and / or video sensors), there are certain uncertainties or inaccuracies in the detection of potential collision objects. Thus, for example, the initiation of a self-braking operation is to be regarded as far more critical than the triggering of an optical and / or audible warning in the event that this is due to an incorrect or inaccurate image or data analysis incorrect. For this reason, currently the visual and / or audible warning can be triggered earlier than autonomous braking or steering assistance.

The above order, however, means that the steering assistance is available only when autonomous braking has already begun. This may leave little time for optimal steering intervention, especially if the autonomous braking is triggered only briefly (for example, less than a second) before the possible collision.

From the DE 10 2004 008 894 A1 Furthermore, an accident avoidance system for a motor vehicle is known in which a driver proposes the vehicle in an emergency avoidance situation an optimal avoidance trajectory. This can be done, for example, in the form of an applied or applied steering torque and / or by a haptic steering assistance, which should enable even inexperienced drivers a safe evasive maneuver. An imminent collision recognizes the vehicle Help of environment detection sensors, eg. B. by radar and / or video. If no evasion is possible and thus no evasion trajectory can be determined, an automatic braking is triggered. Then no steering assistance is provided, but directly initiated a braking.

Also from the DE 10 2013 001 228 A1 an accident avoidance system is known in which an automatic emergency braking occurs when an evaluation of environmental data has revealed that no evasive maneuver is possible. Again, therefore, no steering assistance is provided, but directly initiated braking.

The DE 10 2011 080 789 A1 discloses a method for influencing the driving behavior of a vehicle on the basis of environmental data, in which, when a collision danger is detected, in a first phase a driver's steering is assisted and / or in a second phase a steering of the driver is damped.

Against this background, the object of the present invention is to provide a method and a device with which even safer operation of the motor vehicle, in particular in dangerous situations such as an imminent collision of the motor vehicle with a collision object, becomes possible. In addition, the driver of the motor vehicle should be supported as best as possible in his driving task.

This object is achieved by a method having the features of claim 1 and by a safety device having the features of claim 10. Further particularly advantageous embodiments of the invention disclose the respective subclaims.

It should be noted that the features listed individually in the following description can be combined with one another in any technically meaningful manner and show further embodiments of the invention.

According to the invention, a method for safe operation of a motor vehicle is provided, wherein it is determined by means of a collision detection device whether a collision of the motor vehicle with a collision object is imminent. In this case, the collision detection device can comprise detection of the vehicle surroundings by means of suitable sensors, for example radar and / or video sensors, and be configured to evaluate and decide the sensor data obtained from the sensors at least with respect to an imminent or imminent collision of the motor vehicle with a collision object whether a collision is imminent.

Upon detection of an imminent collision, according to the invention, a brake control device is activated to execute emergency braking of the motor vehicle. The Bremsassistzeinrichtung is therefore adapted to automatically perform an emergency braking of the motor vehicle as a result of their activation, for example, when a predetermined minimum critical distance between the motor vehicle and the collision object is under consideration, taking into account the relative speed between the two objects.

Furthermore, upon detection of an impending collision according to the invention, a steering assist device is activated to assist a driver of the motor vehicle in an emergency avoidance maneuver by applying a steering torque to a steering device of the motor vehicle as soon as it begins to steer.

In other words, a steering torque is applied by the steering assist device after its activation at the steering device as soon as the leader of the motor vehicle begins to direct that the driver of the motor vehicle in his driving task, namely the emergency evasive maneuver is supported.

According to the invention, the steering assistance is provided by the steering assistance device in time prior to the execution of the emergency braking by the brake assistance device. Consequently, as a result of its activation, the brake assistance device automatically performs emergency braking of the motor vehicle after the steering assistance device has applied a steering torque after activation thereof on the steering device. It is thus not determined whether an evasive maneuver is possible and instead carried out an automatic emergency braking, if this is not possible. Rather, there is first a power steering to perform an emergency evasion maneuver and then an automatic emergency braking is performed, for example, if an evasive action was still not successful. This is the case in particular if a predeterminable critical minimum distance between the motor vehicle and the collision object is fallen below, taking into account the relative speed between the two objects, despite the driver performing an emergency avoidance maneuver.

In this way, the operation of the motor vehicle compared to the current state of the art can make even safer, since the driver already before initiating an emergency braking by the Bremsassistzeinrichtung in the execution of an emergency evasion maneuver by the steering assistance device in the event of an imminent collision of the motor vehicle with a collision object is supported. Thus, according to the invention significantly more time remains to perform an optimal steering intervention.

According to an advantageous embodiment of the invention, a strength of the steering assistance by the steering assistance device during the emergency avoidance maneuver depending on a criticality of the collision, that is, depending on an actual distance of the motor vehicle from the collision object, taking into account the relative speed between the two objects, varies. In this case, the strength of the steering assistance is preferably varied in such a way that an increasingly stronger steering assistance is provided on the steering device of the motor vehicle, the closer the motor vehicle is to the collision object.

A further advantageous embodiment of the invention provides that a strength of the steering assistance is varied by the steering assistance device during the emergency evasive maneuver depending on a speed of the motor vehicle. Here, the strength of the steering assistance is preferably varied such that an increasingly smaller steering assistance is provided to the steering device of the motor vehicle, the greater the speed at which the motor vehicle moves. This ensures a stable dynamic behavior of the motor vehicle during the emergency evasive maneuver.

According to yet another advantageous embodiment of the invention, a strength of the steering assistance is varied by the steering assistance device during the emergency evasion maneuver depending on an estimated coefficient of friction between a tire of the motor vehicle and a road surface. Here, the strength of the steering assistance is preferably varied such that an increasingly smaller steering assistance is provided to the steering device of the motor vehicle, the smaller the currently estimated coefficient of friction between the vehicle tire and the road surface. This also leads to an improved dynamic stability of the motor vehicle during the emergency evasive maneuver. The estimation of the coefficient of friction can be carried out, for example, by an ESP control device of the motor vehicle, by monitoring the slip of the vehicle wheels during operation of the motor vehicle and thereby draw conclusions about the instantaneous coefficient of friction between the tires of the motor vehicle and the road surface.

In addition, according to a still further advantageous embodiment of the invention, the steering of the motor vehicle at the beginning of the emergency avoidance maneuver, for example by means of an additional power assistance, be made smoother. This makes it easier for the driver of the motor vehicle to deflect, in particular when initiating the emergency evasive maneuver.

A further advantageous embodiment of the invention provides that an additional, restoring steering torque is applied to the steering device by the steering assistance device during the emergency evasive maneuver as soon as a part of the distance between the motor vehicle and the collision object after the detection of the impending collision is covered by the collision detection device. This makes it easier for the driver of the motor vehicle to redirect the motor vehicle to a lane parallel to the collision object. The partial distance may correspond to half the distance between the motor vehicle and the collision object after the detection of the imminent collision by the collision detection device. Of course, depending on the calculated evasion curve and moving objects of collision, the restoring moment may not be applied exactly halfway along the original path, but preferably prefetched beforehand. Likewise, depending on the escape curve and the moving collision objects, the restoring moment could be applied halfway through the original route between the motor vehicle and the collision object following detection of the imminent collision by the collision detection device.

Furthermore, according to a further advantageous embodiment of the invention, the driver of the motor vehicle can be warned by means of an optical and / or acoustic warning device after detecting the impending collision, wherein the steering assistance is provided by the steering assistance device at the latest at the same time as the issue of the warning. In other words, the steering assistance can be provided even before the output of the visual and / or audible warning. However, it is preferably provided to the driver at the same time as the output of the visual and / or audible warning.

Further preferably, the steering assistance can be overridden by the steering assist device at any time by the driver of the motor vehicle, so that the motor vehicle remains controllable at all times by the driver of the motor vehicle. Thus, the driver of the motor vehicle can execute the emergency evasive maneuver at any time independently of the steering assistance provided on the steering device in order, for example, to steer the motor vehicle to a third lane.

According to a further aspect of the invention, a safety device for the safe operation of a motor vehicle is provided, wherein a collision detection device is provided, which determines whether a collision of the motor vehicle with a collision object is imminent. In this case, the collision detection device can comprise detection of the vehicle surroundings by means of suitable sensors, for example radar and / or video sensors, and be set up to evaluate and decide the sensor data obtained from the sensors at least with respect to an imminent or imminent collision of the motor vehicle with a collision object whether a collision is imminent.

Furthermore, the safety device is set up to activate a brake control device for executing emergency braking of the motor vehicle when an imminent collision is detected. The Bremsassistzeinrichtung is therefore adapted to automatically perform an emergency braking of the motor vehicle as a result of their activation, for example, when a predetermined minimum critical distance between the motor vehicle and the collision object is under consideration, taking into account the relative speed between the two objects.

Furthermore, the safety device is set up, upon detection of an imminent collision, to activate a steering assistance device for assisting a driver of the motor vehicle in an emergency avoidance maneuver by applying a steering torque to a steering device of the motor vehicle as soon as it begins to steer. In other words, a steering torque is applied by the steering assist device after its activation at the steering device as soon as the leader of the motor vehicle begins to direct that the driver of the motor vehicle in his driving task, namely the emergency evasive maneuver is supported.

According to the invention, the steering assistance by the steering assistance device takes place temporally before the execution of the emergency braking by the brake assistance device. The safety device is thus set up so that, as a result of its activation, the brake assisting device automatically performs emergency braking of the motor vehicle after the steering assisting device has applied a steering torque to its activation on activation of the steering device.

In this way, the operation of the motor vehicle compared to the current state of the art make even safer, since the driver is already supported before initiating an emergency braking by the Bremsassistzeinrichtung in the execution of an emergency evasion maneuver by the steering assistance device in the event of an imminent collision of the motor vehicle with a collision object , Thus, according to the invention significantly more time remains to perform an optimal steering intervention.

With respect to a further advantageous embodiment of the safety device according to the invention, reference is made to the advantageous embodiments described herein in connection with the method according to the invention, which can be applied analogously to the safety device.

In a preferred embodiment, the safety device according to the invention is used in a motor vehicle.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004008894 A1 [0009]
• DE 102013001228 A1 [0010]
• DE 102011080789 A1 [0011]

Claims (10)

A method for safe operation of a motor vehicle, wherein by means of a collision detection device is determined whether a collision of the motor vehicle with a collision object is imminent and on detection of an imminent collision Bremsassistenzzeinrichtung is executed to perform an emergency braking of the motor vehicle and a steering assistance device to support a leader of the motor vehicle in a Emergency evasive maneuver by applying a steering torque to a steering device of the motor vehicle, as soon as it begins to steer is activated, characterized in that the steering assistance is provided by the steering assistance means temporally prior to the execution of the emergency braking by the Bremsassistzeinrichtung, wherein the Bremsassistzeinrichtung as a result of their activation automatically emergency braking of the motor vehicle performs after the steering assisting device after its activation at the Lenkeinrichtu ng has applied a steering torque. A method according to claim 1, characterized in that a strength of the steering assistance is varied by the steering assistance device during the emergency evasion maneuver depending on a criticality of the collision. A method according to claim 1 or 2, characterized in that a strength of the steering assistance is varied by the steering assistance device during the emergency evasion maneuver depending on a speed of the motor vehicle. Method according to one of the preceding claims, characterized in that a strength of the steering assistance is varied by the steering assistance device during the emergency evasion maneuver depending on an estimated coefficient of friction between a tire of the motor vehicle and a road surface. Method according to one of the preceding claims, characterized in that the steering of the motor vehicle at the beginning of the emergency evasive maneuver is made smoother. Method according to one of the preceding claims, characterized in that an additional, restoring steering torque is applied to the steering device by the steering assistance device during the emergency evasive maneuver as soon as a partial distance between the motor vehicle and the collision object is covered after the detection of the impending collision. Method according to one of the preceding claims, characterized in that an additional, restoring steering torque is applied to the steering device by the steering assistance device during the emergency evasive maneuver as soon as half of the distance between the motor vehicle and the collision object is covered after the detection of the impending collision. Method according to one of the preceding claims, characterized in that the driver of the motor vehicle is warned by means of an optical and / or acoustic warning device after detecting the imminent collision, wherein the steering assistance is provided by the steering assistance device at the latest at the same time as the issue of the warning. Method according to one of the preceding claims, characterized in that the steering assistance by the steering assistance device can be overridden at any time by the driver of the motor vehicle. Safety device for the safe operation of a motor vehicle, in particular configured for carrying out the method according to one of the preceding claims, wherein a collision detection device is provided which determines whether a collision of the motor vehicle with a collision object is imminent, and the safety device is adapted to detect an imminent collision to activate a Bremsassistenzzeinrichtung for performing an emergency braking of the motor vehicle and a steering assistance device to assist a driver of the motor vehicle in an emergency avoidance maneuver by applying a steering torque to a steering device of the motor vehicle, as soon as it begins to steer, activate the steering assistance by the steering assistance device before the time Execution of the emergency braking by the Bremsassistentzeinrichtung done and the Bremsassistzeinrichtung is set up, due to their Aktivi tion automatically perform emergency braking of the motor vehicle, after the steering assistance device has applied a steering torque after its activation at the steering device.