Method and device for initiating and executing a deceleration of a vehicle

p0001Method and apparatus for initiating and performing a deceleration of a vehicle

p0002Disclosed is a method and apparatus for triggering and implementing a deceleration of a vehicle to avoid a collision or reducing the severity proposed in which by means of at least one radar, lidar or video sensor or a combination thereof recognized objects in the sensor detection area and recognized for each object parameters are ascertained, are allocated based on the determined, related measurements different object classes the detected objects and the movement trajectories of objects are predicted based on the assignment of the detected objects for each class. These predicted movement trajectories of objects and their associated, detected object classes a risk of collision and a Gefährdungsmaß will continue to be identified and in the presence vorgebener combinations of risk of collision and Gefährdungsmaß the deceleration devices of the vehicle are driven accordingly.

p0003State of the art

p0004In the past, systems are increasingly for adaptive distance and speed control on the market come that extend the functionality of a conventional tempo ata in that upon detection of a driving ahead, slower vehicle in front of the own vehicle, the cruise control is switched is followed on a proximity control and the preceding vehicle at the same speed. The basic operation of such a distance and cruise control system is internal in the essay "adaptive cruise control system aspects and development trends" of, Witte et al.,

p0005SAE paper 96 10 10, published on the SAE International Congress and Exposition, Detroit, 26-29th February 1996 is described.

p0006In DE 195 47 111 a method and a device for controlling the brake system of a vehicle is described in which pressure is introduced into the wheel brakes under prescribed conditions before start of a traction control system, with no significant braking effect is applied to the drive wheels.

p0007Core and advantages of the invention

p0008The core of the present invention is accordingly to provide a method and apparatus for initiating and performing a deceleration of a vehicle to avoid a collision or reduce the impact energy. It is particularly intended that the method and apparatus can trigger and perform automatic emergency braking and can therefor perform an automatically controlled steering and / or brake intervention. According to the invention this object is achieved by the features of the independent claims. Advantageous developments and refinements emerge from the subclaims. This happens vorteilhaf legally by a device for distance and speed control detects objects in the sensor detection area of ​​the vehicle and determined measures of each of the detected objects. Due to the determined measurement variables each detected object is associated with an object class and predicted a crowd characteristic, possible motion trajectories due to the associated object class. Furthermore, a risk of collision and a Gefährdungsmaß is determined by the detected object class and the determined movement trajectories, in response to which the deceleration devices of the vehicle can be activated.

p0009The avoidance of a collision in the present case comprises also the reduction of the impact energy to reduce the severity of an impact when collision avoidance is impossible. The risk of collision represents the probability of colliding with the vehicle with a Objket. The vessel hrdungsmaß contrast estimates the risk to the occupants of the vehicle through this possible collision. In the event that two vehicles invariably interfering with the door mirrors at each passing there is a high risk of collision, but only a low Ge ährdungsmaß so that an automatic delay initiation may not be executed.

p0010Furthermore, it is advantageous that the device for distance and speed control of the vehicle is a radar sensor, lidar sensor, a, a video sensor or a combination thereof.

p0011It is also advantageous that it is the determined measured variables to at least one of the variables of the object distance from the host vehicle, relative velocity _ D -

p0012of the object relative to the own vehicle speed, horizontal extent of the object, vertical extent of the object, geometry of the object, in particular geometry of the back of the object as well as to the surface condition of the reflection surface, which is in particular the object back, is. There are also other metrics conceivable which are determined from the received and backscattered radar, lidar or video signals.

p0013Advantageously happens assignment to the object classes based on the determined metrics, whereupon the object of one of the classes person, motorcycle, small passenger cars, large passenger cars, trucks, bus, guardrail, traffic sign, building or another, by the backscattered radar, lidar is or video signals characterizable object.

p0014Advantageously, the classification is done in object classes depending on whether the individual objects can be recognized and assigned by individual sensors or sensor combinations of certain or not, or not detectable.

p0015To determine the trajectories of movement, it is also advantageous that for each object class a characteristic driving dynamics model is stored, with the help of which can be determined to be predicted crowd of possible movement trajectories with increased accuracy.

p0016It is also advantageous that the risk of collision and the Gefährdungsmaß representing the probability of a collision with a detected object, unless a driver intervention takes place. In the case of a scalar Collision risk and hazard of a scalar measure, it is preferable that the delay means are triggered when thresholds are exceeded. Furthermore, it is conceivable that the risk of collision and the Gefährdungsmaß one or more vector quantities and that for triggering the delay devices of the vehicle specific vector conditions must be met. Furthermore, it is advantageous that the threshold scalar or vectorial trigger condition is not constant but a function of the traffic situation can be changed. Thus, it is advantageous that the activation of the delay means can be adjusted in dependence of the momentary situation environment.

p0017Furthermore, it is advantageous that the threshold value in dependence on the driver's activity, thus the operation of the accelerator pedal, the brake pedal or the steering wheel, is variable. Thereby, it is possible to trigger the delay devices until a critical point in time when it is detected that the driver attempts itself a braking or evasive action. If it is detected that the driver does not carry out activities, then one can be already taken a trip to uncritical situations.

p0018It is also particularly advantageous that in predicting the trajectories of movement of the own vehicle and the detected objects, only the trajectories are taken into account, where as a result of a combination of steering and braking intervention that are not greater on the wheels of the vehicle forces occurring when the maximum transferable from the wheel to the road force. By eliminating the movement trajectories in which the steering and braking forces occur that can not be transferred to the road from the wheel, allows the computing power that is necessary to determine the Bewegungstrajetorien, reduce and thus increase the efficiency of the system.

p0019Of special significance is the realization of the inventive method in the form of a control element is provided for a control unit of an adaptive distance and speed control of a motor vehicle. A program is stored on the control that is suited to a computer, in particular on a microprocessor or ASIC, executes and for performing the method according to the invention. In this case, the invention is realized by a program stored on the control program, so that this control element provided with the program in the same way the invention as the method for whose execution the program is suitable. As a control element, especially an electric storage medium can be used, for example, a read only memory.

p0020Further features, application possibilities and advantages of the invention will become apparent from the following description of embodiments of the invention, which are illustrated in the drawing figures. All the features themselves or in any combination described or illustrated form the subject matter of the invention, irrespective of their summary in the claims or their dependencies and irrespective of their formulation or representation in the description or in the drawing. drawings

p0021Embodiments of the invention are explained with reference to drawings. Show it

p0022Figure 1 is a flow chart for performing the method according to the invention, Figure 2 is a device for performing the method according to the invention.

p0023Description of embodiments

p00241 shows a flow diagram of an embodiment of the inventive method. This flowchart illustrates a continuous loop and will constantly undergo new. In block 1 is determined by the environment sensor in the form of a radar, lidar or video sensor, how many objects are in the sensing zone. This n detected objects are stored in memory. In block 2 of the flowchart, the reading of the measurement data for each of the n objects are. This case include various sizes, which are provided directly by the environment sensor. The measured variables can be one or more of the following variables: speed of the object relative to the host vehicle, distance of the object, horizontal extent of the object, vertical extent of the object, geometry of the object and surface characteristics of the reflection surface. These metrics at time t + .DELTA.t are compared with the measurement data of the previous measurement cycle at time t to determine if it is the detected object is a first recognized object or whether it is a Berits recognized and now continue moving object. From the time derivative of these changes also other sizes can be derived, for example, the acceleration from the measured velocity values. In the subsequent step 3 is with reference to the corresponding to the object data selected an object class. This is done for example by correlating the characteristic object classes with the measurement data. When object classes are characteristic patterns of the respective objects. For example, has a motorcycle another radar cross-section than a truck or a vehicle to another characteristic velocity than a standing building. Due to such characteristics of the object classes to each object is supplied assign an object class in the measurement data of each object by means of a correlation analysis. In step 4 of the flow chart, the prediction of a flock of movement trajectories for each of the n objects are. For this purpose, use is made of a characteristic driving dynamics model, which is stored for each of the object classes. So a motorcycle, for example, be able to quickly perform steering movements than is possible for a bus or a lorry. The respective driving dynamics model which is made according to the detected object class to help is linked to the read-in step 2 measurement data, whereby a precise coulter

p0025Motion trajectories can be calculated in advance, than would be possible without driving dynamics model. Parallel to steps 1 to 4 of the flow chart, the data of the own vehicle movement detected in block 10 and block 11 determines in a movement trajectory of the host vehicle. In step 5 is based on the band of movement trajectories, which were determined for the host vehicle and determined based on the droves movement trajectories, which were determined for the detected objects, a collision risk and a Gefährdungsmaß. This collision risk determines the probability that a collision of the own vehicle is imminent with the n objects. This Collision risk can be either a scalar value that is the greater, the higher the probability of a collision. Furthermore, it is also conceivable that the risk of collision is a vector quantity, whereby the situation by means of a series of criteria to be assessed. The determined Gefährdungsmaß other hand takes into account the risk to the occupants of the vehicle to take on the risk of collision considerate without. Also this size can be designed scalar or vector. In step 6, an inquiry is made whether the determined in step 5

p0026Collision risk is greater than a certain threshold and whether the SW1 Gefährdungsmaß is greater than a certain threshold value SW2. If it is determined in which in step 5 sizes collision risk and Gefährdungsmaß to a vector quantity, so when the query in step 6, a multi-criteria search is necessary. So it is conceivable that only one value of the vectors collision risk and / or Gefährdungsmaß, meet the conditions must, or that all the values ​​of the vectors must satisfy the Yes-conditions for each. Furthermore, it is also conceivable that a particular pattern of the vectors must be met in order to proceed further with a yes decision. If Step 6 answers as No, the flow branches to the circle A and starts with step 1 again anew. If the branch is in step 6 to Yes, as preparatory measures for a bevorherstehende emergency braking can be initiated. These preparatory measures may for example be to inform the driver by means of an acoustic, optical or kinesthetic device about the current collision risk or there is a restraint system for vehicle occupants prepared or activated or the engine speed is lowered to idling speed or brought the transmission in neutral, so that no power transmission takes place more or storage of measurement data in a nonvolatile storage medium performed or made a combination of the measures described. In the example shown here, only a threshold is evaluated for performing one or more preparatory actions. Part of the invention, however, it is also possible that for each of the measures described, a separate preliminary threshold value is defined, which must be exceeded for each activation. In this case, takes a decision for each action step, similar to step 6, and an action step, similar to step 7, are performed in succession. In step 8 of the flow chart is decided whether the risk of collision is greater than a threshold value SW2. If this is not the case, the chart-forgives to A, whereby the program jumps to the start and the algorithm restarts at step. 1 If the condition at decision step 8 to answer yes, then further processing is done in step 9 by the Verzögerungsπiittel are driven. The decision in step A can also here again in either scalar form or in vector form, similar to Step 6, are carried out. If the delay means driven in step 9, an automatic emergency braking is initiated and braked in the other vehicle until the vehicle is at a standstill or to run again to the flow chart is a termination for deemed favorable. After activation of the delay means in block 9, the flowchart proceeds to step 1 and passes through this cycle again. The delay means remain activated and can in the next cycle, if the delay conditions are no longer met, be solved.

p0027Figure 2 shows an inventive device for implementing the method according to the invention. The A device 10 for initiating and performing a deceleration of a vehicle includes an input box 11, the one or more input signals 14 to 15 of sensor devices 12 can be supplied to the thirteenth As sensor devices 12 to 13 come to a a radar, lidar or video sensor or a combination thereof into consideration, as well as other institutions with which the host vehicle behavior can be detected. For example, here are devices for determining the own vehicle speed, yaw rate, vehicle movement direction, brake pedal, accelerator pedal operation and a steering angle sensor to call. The incoming input in the box 11 signals are fed by means of an evaluation unit 16 Datenttransportsystems 17th In the evaluation unit 17, the process for initiating and performing the vehicle deceleration is carried out to avoid a collision. This evaluation 17 are subject to vehicle situation and environment situation of output signals which are fed to an output box 18 by means of data transport system 16th This is, for example, to signals that inform the driver in audible, visual or kinesthetic form of the current risk of collision, or to signals in preparation or activation of restraint systems such as airbags or belt tensioners, or it is a signal for lowering the engine speed spent idle speed or a signal output which places the transmission in neutral position, so that no energy transfer takes place or in immediate imminence of a collision are measurement data that have been supplied to the input field 11 is stored in a nonvolatile storage medium. Another output signal which can be output via the output array 18 is a signal for driving the delay means. It should be mentioned that the Verzogerungsmittel be prepared before initiating the emergency braking by the brake system is prefilled and the brake pads are applied to the brake discs, without significant braking forces. Another output of the delay means, the triggering of the emergency braking represent, whereby a maximum possible delay is applied. Another signal that can be fed to the delay means, a signal which causes a delay portion, that is a delay, the braking effect is between the maximum possible braking effect and no braking effect. The signals 21 to 22 which are output via the output pad 18 serve as input variables for further processing devices 19 to 20. As a possible means 19, 20 are in particular the delay means to call, however, the motor controller Getriebesteueurng, a

p0028Performance data memory, a control unit for restraint systems, or a driver information device.