Emergency braking assistant for a vehicle

Abstract

Method for automatic emergency braking of a vehicle (3) comprising the steps: - object detection in the area in front (13) and behind (15) the vehicle (3); and - setting at least one emergency braking parameter as a function of at least one detected object (9) in the area in front (13) of the vehicle (3); characterized in that - standard parameters (27) are set as emergency braking parameters when an object (11) is detected in the area behind (15) the vehicle (3), and - at least one optimum parameter (29) is defined as at least one emergency braking parameter which is optimal compared to the standard parameter (27) in order to prevent a collision with the object in front of the vehicle or to reduce the severity of the collision if no object (11) is detected in the area behind (15) the vehicle (3), - if an object (11) is initially detected in the area behind (15) the vehicle (3) and then at a certain point in time no object is detected, at least one emergency braking parameter is subsequently modified from a standard parameter (27) to an optimal parameter (29), and - if no object (11) is initially detected in the area behind (15) the vehicle (3) and then an object is detected at a point in time, at least one emergency braking parameter is subsequently modified from an optimal parameter (29) to a standard parameter (27).

Description

The present invention relates to an improved emergency braking assist system for a vehicle which takes into account the rear range in determining emergency braking parameters. The reverse range is also monitored during the emergency braking process and the emergency braking parameters are optionally adapted.Prior ArtIn vehicles, environment monitoring systems are increasingly being used. The acquired information of these systems can be used for automatic emergency braking of the vehicle, among other things. However, emergency braking is always associated with a risk for the following traffic. The recorded data of the environment monitoring systems must therefore be reliable and the emergency braking must take place within an optimum range in order to prevent, on the one hand, a collision with an object located in front of the vehicle and, on the other hand, with a following vehicle.DE 10 2010 029 223 A1 discloses a mathematical model which is used to abort an emergency braking process initiated according to the prior art or to reduce the braking force in order to limit the severity of a future rear-end collision and at the same time to achieve a sufficient braking action.EP 2 595 135 A1 describes a collision avoidance system for a vehicle in which a target object in front of the vehicle and one or more further obstacles which prevent the vehicle from safely passing by the target object are detected. In this case, the risk of a collision between the vehicle and the target object is evaluated, wherein the further obstacles are also included in the risk evaluation, wherein automatic emergency braking of the vehicle is initiated on the basis of the risk evaluation.FR 2 915 160 A1 discloses an assistance system for a vehicle, wherein a risk of collision between the vehicle and an obstacle in front of the vehicle, which is detected with a sensor directed forward, is detected and the vehicle is stopped with respect to the obstacle. Furthermore, a distance between the vehicle and a following vehicle is determined by a rear-facing sensor, this distance being included in the stopping process with a setpoint function with respect to the signals supplied by the front and rear sensors.JP 2010-52 546 A discloses a vehicle travel control apparatus including an obstacle detection device that detects an obstacle present in front of the vehicle, a collision control device that applies a braking force to the vehicle by activating a braking device when a collision of the vehicle with an obstacle is predicted on the basis of information supplied from the obstacle detection device, and a following vehicle detection device that detects a following vehicle traveling behind the vehicle. When a collision with an obstacle in front of the vehicle is predicted and the presence of a following vehicle is detected, the brake device is activated by the collision control means at a timing earlier than in the case where no following vehicle is detected.Furthermore, DE 10 2007 022 589 A1 describes a predictive safety device for motor vehicles, having a front-end sensor system for locating objects in the front-end of the vehicle and a control unit which evaluates the signals of the front-end sensor system in order to evaluate the risk of an imminent collision and which, in the event of an acute risk of collision, intervenes in the longitudinal guidance of the vehicle in order to eliminate the collision or to mitigate its consequences, wherein a supplementary sensor system is provided for locating objects in the other environment of the vehicle and the control unit is configured to calculate, on the basis of the data of the supplementary sensor system, a longitudinal guidance strategy which minimizes the overall risk taking into account objects in the other environment.Object and SolutionIt is an object of the present invention to improve an emergency braking assistant and a method for operating an emergency braking assistant.The object is achieved by the subject matter and the method of the independent claims. Further advantageous embodiments are the subject matter of the dependent claims.According to the invention, the method for automatic emergency braking of a vehicle has the following steps: an object detection in the area in front of and behind the vehicle; and a determination of at least one emergency braking parameter as a function of at least one detected object in the area in front of the vehicle; wherein at least one emergency braking parameter is modified if no object, in particular no following vehicle travelling, is detected in the area behind the vehicle.In an advantageous manner, in the absence of objects in the area behind the vehicle, emergency braking can take place with the optimum parameters, since no consideration must be taken of the traffic to the rear.The emergency braking parameters can preferably comprise at least one permissible speed range within which the emergency braking assistant is active; or a deceleration request; or a speed reduction; or the time of the emergency braking.Advantageously, the speed range or the deceleration requirement or the speed reduction can be set to an optimum value in order to prevent a collision with the object in front of the vehicle or to reduce the severity of the collision. An optimum value could be, for example, the maximum possible deceleration power of the brakes of the vehicle. Optimum values for the speed range are, among other things, the values for standardized speed limits inside and outside locations, i.e. the ranges 30- 50, 70- 100 and 130 km / h. In particular, emergency braking can take place in each speed range, since there is no risk due to a rear-end collision due to the missing objects in the rear region.More preferably, the emergency braking parameter may be modified as follows: the allowable speed range is increased or the deceleration request is increased or the deceleration is increased or the time of emergency braking is advanced.More advantageously, the emergency braking time may be advanced to have more time to decelerate the vehicle. An impairment of other road users is finally prevented by object detection in the rearward region.In a further preferred embodiment of the invention, the object detection can take place continuously in the region behind the vehicle.Advantageously, it can be recognized in a predictive manner that the area behind the vehicle is free of further objects and emergency braking is carried out with modified or increased emergency braking parameters. In particular, the rear range can thereby also be monitored during emergency braking.Preferably, the increase of at least one of the emergency braking parameters can be maintained until an object, in particular a following vehicle traveling, is detected in the area behind the vehicle.In an advantageous manner, a detected object in the rearward region can thus be taken into account before or during the emergency braking, and the initiation or further execution of the emergency braking can be adapted to changing traffic situations. In particular, the increase in the emergency braking parameters can be decreased and the standard parameters are used.In an advantageous embodiment of the invention, the object detection in the area behind the vehicle can determine a relative speed or a distance of the detected objects.Advantageously, the distance and the relative speed can provide information about the future behavior of the following object and thus the emergency braking parameters to be taken into account in the further course of the emergency braking.In particular, each mishandling situation can thus be dealt with individually and the emergency braking takes place with the emergency braking parameters tailored to the following object.Further preferably, the increase of at least one emergency braking parameter can be effected dynamically with the relative speed or the distance of the detected object.Advantageously, the adaptation of the emergency braking parameters can take place continuously during the emergency braking and the emergency braking parameters can thus be adapted to the emergency braking behavior of the host vehicle or to the behavior of the following object.In an advantageous embodiment of the invention, an avoidance maneuver can be carried out if a collision with the detected object in the area in front of the vehicle and the detected object in the area behind the vehicle, in particular a following vehicle traveling, can no longer be prevented by emergency braking.Advantageously, when it is determined during emergency braking that braking to avoid an accident with the obstacle or the following object can no longer be prevented despite adaptation of the emergency braking parameters, an avoidance process can be initiated. In particular, an accidental emergency braking of the vehicle can thus be avoided.According to the invention, an emergency braking assistant for a vehicle comprises an object recognition unit for the area in front of and behind the vehicle; and a control unit for carrying out the preferred method, wherein the control unit comprises an electronic memory on which a method according to one of the preceding claims is stored.DESCRIPTION OF THE FIGURESFIG. 1 shows a traffic situation 1 with a plurality of vehicles 3, 9, 11 The middle vehicle 3 is equipped with an object detection unit 5, 7 for the area in front of 13 and behind 15 of the vehicle 3, respectively. The respective object detection unit detects objects in front of 13 and behind 15 the vehicle 3 if objects 9, 11 or vehicles are located in this area. FIG. 2 shows a flow chart for the operation 21 of an emergency brake assist system. The object detection unit 23 monitors the rear area of the vehicle and searches for objects in this area 25. If, on the other hand, no objects are detected 33 in the rearward region 25, an emergency braking operation, which may need to be initiated, is carried out with optimum parameters 29 as emergency braking parameters that are increased compared to the standard parameters.The method shown in FIG. 2 for the operation 21 of the emergency braking assistant is also carried out during an emergency braking already taking place. If, after the start of the emergency braking process, the object detection unit 23 detects 31 an object in the rear region 25, then the emergency braking with the standard parameters 27 is continued. The increased optimum parameters 29 are therefore no longer used. Instead of equally using the standard parameters 27, intermediate parameters can also be used which lie between the optimum parameters 29 and the standard parameters 27.FIG. 3 shows a diagram for the course of an emergency braking parameter 41. for example, the course of the permitted speed reduction (in kph) 43 is plotted over time (msec) 45. At the beginning, no object in the rearward region is detected and any emergency braking that may take place would be carried out 47 with the optimum parameters that are increased compared to the standard parameters.At time 49, the object detection system detects an object in the rear area of the vehicle and dynamically reduces the permitted speed reduction depending on the speed and the distance of the detected object back to the standard parameters 53.FIG. 4 shows an emergency braking unit 60 for a vehicle. The object detection unit 5, 7 for the area in front of 13 and behind 15 the vehicle monitor the respective traffic space and determine the relative speed and the distance of the detected objects 11, 9. the control unit 65 then adjusts the emergency braking parameters to the detected objects and controls the brake system 67 of the vehicle accordingly.

Claims

Method for automatic emergency braking of a vehicle (3), having the steps: - an object detection in the region in front of (13) and behind (15) the vehicle (3); and - a determination of at least one emergency braking parameter as a function of at least one detected object (9) in the region in front of (13) the vehicle (3); characterized in that - standard parameters (27) are determined as emergency braking parameters if an object (11) is detected in the region behind (15) the vehicle (3), and - at least one optimum parameter (29) is determined as at least one emergency braking parameter which is optimum with respect to the standard parameter (27) in order to prevent a collision with the object in front of the vehicle or to reduce the severity of the collision if no object (11) is detected in the region behind (15) the vehicle (3), if an object (11) is detected at the beginning in the area behind (15) the vehicle (3) and then no object is detected any longer at a time, at least one emergency braking parameter is subsequently modified from a standard parameter (27) to an optimum parameter (29), and if no object (11) is detected at the beginning in the area behind (15) the vehicle (3) and then an object is detected at a time, at least one emergency braking parameter is subsequently modified from an optimum parameter (29) to a standard parameter (27).Method according to claim 1, wherein the emergency braking parameter is at least one of the following: - an allowed speed range within which the emergency braking assistant is active, or - a deceleration request, or - a speed reduction, or - time of the emergency braking.Method according to claim 2, wherein the emergency braking parameter is modified from the standard parameter (27) to the optimum parameter (29) as follows: - the permissible speed range is increased, - the deceleration request is increased, or - the speed reduction is increased, or - the time of the emergency braking is advanced.Method according to one of the preceding claims, wherein the object detection takes place continuously in the region behind (15) the vehicle (3).Method according to one of the preceding claims, wherein the modification of at least one of the emergency braking parameters is maintained until an object (11) is detected in the region behind (15) the vehicle (3).Method according to one of the preceding claims, wherein the object detection in the region behind (15) the vehicle (3) determines a relative speed or a distance of the detected objects (11).Method according to claim 6, wherein the increase of at least one of the emergency braking parameters is dynamically modified with the relative speed or the distance of the detected object (11).Method according to one of Claims 5 to 7, wherein an avoidance maneuver is carried out if a collision with the detected object (9) in the region in front (13) of the vehicle (3) and the detected object (11) in the region behind (15) of the vehicle (3) can no longer be prevented by emergency braking.Emergency braking assistant (60) for a vehicle (3), comprising - an object recognition unit (5, 7) for the region in front of (13) and behind (15) the vehicle (3); and - a control unit (65) for carrying out a method according to one of the preceding claims, wherein the control unit (65) comprises an electronic memory on which the method according to one of the preceding claims is stored.

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