EP1907234A1

EP1907234A1 - Method and device for preventing rear end collisions

Info

Publication number: EP1907234A1
Application number: EP06763589A
Authority: EP
Inventors: Hans-Joerg Mathony; Alfred Kuttenberger; Mario Kroeninger; Dirk Meister; Michael Bunse; Stephan Spaeth
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2005-07-15
Filing date: 2006-06-08
Publication date: 2008-04-09
Also published as: US20100134263A1; CN101223048A; WO2007009843A1; JP2009500243A; DE102005033087A1

Abstract

The invention relates to a method and a device for preventing rear end collisions with a vehicle. According to the invention, the distance (d) and/or speed (vrel) of the vehicle in relation to the vehicle in front are determined by means of an environmental sensor (2) oriented towards the front region of the vehicle. In the event of a stopping situation, a longitudinal dynamic value (alphaFP, alpha BP) initiated by the driver is evaluated in order to determine whether there is a risk of collision for the two vehicles in question. In the event of a risk of collision, the drive train (10) and/or the delay devices (11) of the vehicle are engaged in order to reduce the risk of collision and/or driver warning devices (12, 5) are triggered in order to inform the driver about the risk of collision.

Description

Method and device for avoiding rear-end collisions

The present invention relates to a method and a device for avoiding rear-end collisions when starting behind a preceding vehicle, wherein the distance and / or the speed to the preceding vehicle is determined by means of an environment sensor system oriented in the vehicle apron

If there is a starting situation, a driver-actuated longitudinal dynamic specification is evaluated as to whether there is a danger of collision of the own vehicle with the vehicle ahead and if there is a danger of collision in the drive train and / or the deceleration devices of the vehicle intervene in order to reduce the risk of collision and / or driver warning devices are activated Inform driver about the risk of collision.

State of the art

From DE 102 18 017 Al a method for speed and

Distance control in motor vehicles is known in which the distance of a preceding vehicle is measured and for the distance control at least two operating modes are provided which can be activated in different overlapping speed ranges, and wherein the switching between these operating modes at least in one direction only by a driver command is possible, wherein the speed of the preceding vehicle is extrapolated into the future based on the speed of the own vehicle and the measured distance and / or relative speed data and that a switching request is issued to the driver when the extrapolated Speed is out of range for the current mode and the current speed is within the allowable range for the other mode.

Core and advantages of the invention

The essence of the present invention is to provide a method and a device with which the risk of rear-end collisions when approaching behind a preceding vehicle can be avoided by a risk of collision is determined and depending on the degree of risk of collision in the drive train and or the deceleration devices of the vehicle intervene is too strong

To avoid accelerating the vehicle and the driver is informed by means of a driver warning device on the increased risk of collision. In this case, a starting situation can be recognized by the fact that the vehicle ahead was detected as stationary by means of the environmental sensor system and an acceleration of the own vehicle is measured in the subsequent measuring cycles. By

Evaluation of the longitudinal dynamics specifications of the driver, which is derived from the current accelerator pedal operating angle and the current brake pedal operating angle, can be determined with the aid of the current distance d and the current relative speed v _rel a risk of collision. In this case, the powertrain control is intervened by, for example, the

Accelerator characteristic is reparameterized, so that at a certain accelerator pedal actuation angle α _F p a lower acceleration request is issued than in the usual driving this angle α _F p is assigned. This results in a lower acceleration request to the vehicle, whereby at an increased risk of collision, the vehicle is accelerated less than the driver is used to from the usual driving. The intervention in the deceleration devices of the vehicle may be configured such that a brake pressure build-up of the wheel brakes is automatically built up and controlled, so that the vehicle acceleration is simultaneously braked by the accelerator operation of the driver to prevent an excessive acceleration of the own vehicle at an increased risk of collision.

Furthermore, it can be prevented by the automatic brake pressure build-up that when starting on a slope, the own vehicle rolls away when the driver does not press the accelerator pedal in time or accelerates the vehicle less than the driver is used to from the other driving situations, because at the same time the accelerator characteristic is reparameterized. Furthermore, the driver can over the increased risk of collision be informed, for example, by activating audible or visual warning devices or by using, for example, an accelerator pedal with active restoring force, in which the resistance of the accelerator pedal is electrically controlled. In the case of an increased risk of collision, it is possible here to increase the restoring force of the accelerator pedal F _FP , so that the driver feels an increased back pressure on the accelerator pedal, whereupon he intuitively reduces the accelerator pedal actuation angle α _FP , so that the risk of collision is reduced. According to the invention this is achieved by the features of the independent claims. Advantageous developments and refinements emerge from the subclaims.

Advantageously, a starting situation is detected when the own vehicle accelerates from standstill and the own vehicle speed is below a predetermined limit speed.

Furthermore, it is advantageous for the environment sensor system to be an ultrasound sensor

Radar sensor, a Lidarsensor, a Photonic Mixing Device (PMD) sensor, a video sensor or a combination of these types of sensors is.

Furthermore, it is advantageous that the driver-actuated longitudinal dynamic specification is an accelerator pedal actuation and / or a release of the brake pedal.

Advantageously, the intervention in the drive train of the vehicle by a change in the accelerator pedal characteristic. The accelerator characteristic here is the assignment of an acceleration request or an engine torque request as a function of the currently set accelerator pedal angle α _FP , wherein in this Anfahrsituation the characteristic can be changed such that at the same accelerator pedal angle α _F p a lower acceleration request or a lower engine torque request is issued as it is provided in the usual driving.

Furthermore, it is advantageous that the intervention in the deceleration devices is carried out by an automatic brake pressure build-up to complicate a collision-hazardous, driver-actuated starting. Advantageously, the intervention takes place in the deceleration devices by an automatic brake pressure build-up to prevent a rolling back of the own vehicle when starting on a slope. The rolling back of the own vehicle when starting on an incline can be favored by the fact that the accelerator characteristic has been reparameterized, so that at a certain accelerator pedal angle α _F p a lower acceleration request or lower engine torque request is output, as is provided in the usual driving, thereby starting up On the mountain, this reparameterization can make the actually requested acceleration or engine torque requirement so low that the own vehicle can roll back without the driver being prepared for it.

In particular, the combination of the Umparametrierung the accelerator characteristic with the automatic brake pressure build-up has the consequence that even in this Anfahrsituation on a slope of the following road users is not more at risk than without the inventive system. In order to be able to detect a start on the mountain, a longitudinal acceleration sensor can be provided, which provides a longitudinal acceleration signal a _x . Optionally, the longitudinal acceleration a _{x can} also be used from a time derivative of the relative speed of objects that were detected by the surroundings sensor as standing objects.

Furthermore, it is advantageous that the driver warning by means of an accelerator pedal with electrically controllable restoring force, wherein at an increased risk of collision, the restoring force F _{FP of} the accelerator pedal is increased. Such danger pedals are already available on the market and are known, inter alia, under the name force feedback pedal.

Furthermore, it is advantageous for the driver warning device to be provided with an acoustic signaling device, for example in the form of a text output or in the form of a buzzer. In addition to the acoustic signaling device or as an alternative to this, it is also possible to provide an optical driver warning device, for example by activating a warning light or a plain text output in the

Display of the dashboard is output.

Advantageously, the driver can deactivate the collision avoidance function at any time by means of an accelerator pedal override. Furthermore, it is advantageous that the collision avoidance function is only active below an upper limit speed. As an upper limit speed, for example, a speed threshold between 10 km / h and 20 km / h is conceivable, since at higher speeds of a normal driving operation can be expected and the startup process is completed.

Furthermore, it is advantageous that the collision avoidance function is deactivated by a driver intervention in the drive train by overriding the accelerator pedal and / or a driver intervention in the deceleration devices by actuation of the brake pedal. This gives the driver at any time the opportunity through a targeted

Depression of the accelerator pedal or the brake pedal to override this collision avoidance function and continue the vehicle to his individual specifications.

Of particular importance is the realization of the method according to the invention in the form of a control element which is suitable for a control device of a distance control or

Cruise control of a motor vehicle is provided. In this case, a program is stored on the control, which is executable on a computing device, in particular on a microprocessor or signal processor, and suitable for carrying out the method according to the invention. In this case, therefore, the invention is realized by a program stored on the control, so that this with the

Program provided control in the same way as the invention, the implementation of which the program is suitable. In particular, an electrical storage medium can be used as the control, for example a read-only memory.

Other features, applications and advantages of the invention will become apparent from the following description of embodiments of the invention, which are illustrated in the figures of the drawing. All described or illustrated features, alone or in any combination form the subject matter of the invention, regardless of their summary in the claims or their

Back relationship and regardless of their formulation or presentation in the description or in the drawings. drawings

Hereinafter, embodiments of the invention will be explained with reference to drawings. 1 shows a schematic block diagram of an embodiment of the device according to the invention, and FIG. 2 shows a flowchart of an embodiment of the method according to the invention.

Description of exemplary embodiments

FIG. 1 shows a schematic block diagram of a device according to the invention. Evident is the collision warning and avoidance device 1, which has an input circuit 2, by means of which the collision warning and - avoidance device 1 input signals can be fed. As input signals, the input circuit 2 is supplied with output signals of an environmental sensor system 3, which can be embodied, for example, as an ultrasonic sensor, as a radar sensor, as a lidar sensor, as a video sensor, or as a combination of these sensor types. This environment sensor system 3 is aligned such that the vehicle front environment is detected and objects located therein, such as preceding vehicles or preceding, stopped vehicles are detected and their distance d to the own vehicle and their relative speed v _{rel is} determined. Furthermore, it is possible to use a sensor system 3, which can determine an azimuth angle at which the object in front was detected. These object-related measured variables are forwarded by the environment sensor 3 to the input circuit 2. Furthermore, a speed _sensor 4 is provided, which detects the instantaneous speed of the own vehicle and as a measured variable v _Fzg also to the input circuit 2 of the collision warning and -Vermeidungseinrichtung 1 supplies. As a further input quantity, the input circuit 2 is supplied with the accelerator pedal actuation angle α _F p, which indicates by which amount the accelerator pedal 5 has been deflected by the driver and to which an acceleration request or an engine torque demand can thus be assigned. Furthermore, the input circuit 2, a brake pedal actuation angle α _B p of the brake pedal 6 is supplied, which indicates the extent to which the brake pedal has been deflected by the driver or whether the driver does not currently operate the brake pedal 6. Furthermore, provision may be made for the input circuit 2 to be supplied with the longitudinal acceleration a _x of its own vehicle as a further input signal, with which a standing or approaching on a slope can be detected. For this purpose, a longitudinal acceleration sensor 21 may be provided. Alternatively, however, this information can also be determined by time derivative of the relative speed of stationary objects, for example, at the roadside, by means of the environment sensor. The input signals 2 supplied input signals by means of a

Data exchange device 7 a calculation device 8 supplied, which may be embodied for example as a microprocessor. The calculation device 8 contains a program which processes the method according to the invention in the form of control information and calculates the input signals fed in dependence on the input circuit 2 on output signals which are connected downstream

Setting devices are issued. These output signals are output by the computing device 8 by means of the data exchange device 7 to an output circuit 9, to which the downstream actuators are connected. As a control element that influences the drive train of the vehicle, a power-determining actuator 10 of an internal combustion engine is provided, for example, as an electrically controllable throttle or as

Fuel quantity measuring device may be implemented in the form of an injection valve and which regulates the internal combustion engine depending on the driver requested acceleration request or engine torque request. As a further adjusting element, the deceleration device 11 of the vehicle is provided, which has, for example, an electrically controllable brake booster and converts an output from the output circuit 9 control signal into a corresponding brake pressure or vehicle deceleration and the vehicle as a function of the brake pedal actuation angle α _B p or regardless of a driver operation automatically performs a delay. This makes it possible for the

Collision warning and avoidance device 1 can engage in the deceleration devices 11 of the vehicle. As a further control element a driver warning device 12 is provided, which may be embodied for example as an acoustic and / or optical Sinaieinrichtung, for example in the form of a flashing warning light, a plain text display on the display of the vehicle dashboard, as a warning buzzer or in the form of a machine text output via a speaker. As a further possibility to inform the driver about an increased risk of collision, an active accelerator pedal 5 can be provided which can generate an electrically controllable restoring force, whereby the counterforce of the pedal against the driver's foot is adjustable. By outputting a control signal F _FP by the output circuit 9, it is possible to restore the restoring force of the Set accelerator pedal 5 accordingly and to signal to the driver thereby that he should operate the accelerator pedal less. This makes it possible not only to inform the driver acoustically or visually by means of the signaling device 12, but also to influence the driver intuitively, alternatively or additionally via the feeling of pressure in the foot, in order to communicate a risk of collision and to reduce the risk of collision.

FIG. 2 shows a flow chart of the method according to the invention. This process starts in step S13 and is continued in step S14, where it is checked whether a starting situation has been detected. The starting situation can be recognized by the surroundings sensor 3 detecting a vehicle in front that is at a standstill. If it is determined that the own vehicle, e.g. by requesting an engine torque, is accelerated and is no longer at standstill, a starting situation is detected and step S 14 branches off, yes. "If no starting situation is detected in step S 14, then the flowchart branches off

"No" and is ended in step S _{20. If a starting situation was} identified in step S 14, the flowchart in step S 15 is continued by checking the vehicle speed v _Fzg determined by the speed _sensor 4, whether this is greater than a predetermined limit speed v _limit In this _case , the limit speed vc _renz represents an upper speed _threshold up to which the method _according to the invention is active: If the own vehicle speed V _{Fzg lies} above the upper limit speed v _limit , which can be between 10 km / h and 20 km / h, for example If it has been determined in step _S11 that the current vehicle speed V _{Fzg is} greater than this limit speed V _limit , then the method branches to "Yes" and is ended in step S20 , It was recognized that the vehicle speed v _Fzg is less than or equal to the limit speed Vc i _E _Re is, the process in step S16 is continued, in which the measured values of the distance d of the detected located ahead the vehicle to the host vehicle, the relative velocity v _rel of the located ahead Vehicle with respect to the own vehicle, the current accelerator pedal angle α _FP and the current brake pedal actuation angle α _B p are determined and processed in the calculation device 8. By means of the accelerator pedal operation angle α _FP , α _B p, it is possible to determine whether the driver has released the brake pedal and actuates the accelerator pedal, that is to perform a starting process of the own vehicle wants and how much he wants to accelerate his own vehicle to start and how quickly the preceding vehicle away by the distance d and the relative speed vrel are evaluated. From the values relating to the driving dynamics of the vehicle ahead as well as the driver request signals α _F p and α _B p, a collision risk is calculated in the following step S 17, for example by calculating how much time remains until a potential collision with the preceding vehicle would occur if the own vehicle would continue to operate with the current acceleration requirements. However, it is also conceivable to detect a risk of collision by means of other algorithms, for example by depositing multidimensional tables which _assign corresponding collision risk values to the corresponding measured values d, v _rel , α _FP and α _B p. In the following step Sl 8, several measures S 18a to S18d are listed, wherein depending on the embodiment of the invention, only one of these measures S 18a to S18d executable, any combination of these measures is executable or all the described measures S18a to S18d can be performed together. Thus, according to S 18a, it is provided that the accelerator characteristic is reparameterized in accordance with the collision risk determined in step S17, so that at a specific accelerator pedal angle α _FP an acceleration request or engine torque request is output that is less than at the same accelerator pedal angle α _FP in the conventional driving mode. According to step S 18b, alternatively or in combination with step S 18a, it is possible to build up an automatic brake pressure build-up depending on the collision risk calculated in step S17, so that the vehicle is accelerated less by the accelerator operation of the driver because the vehicle deceleration devices 11 oppose the acceleration request act or when starting on a slope

Rolling back your own vehicle is avoided. According to step S 18c, which may be provided as an alternative to steps S 18a and S 18b or in any combination with these, an output of a driver warning is provided by an acoustic and / or optical signaling device 12 to alert the driver to the existing risk of collision. According to step S18d, it is optional or alternative to those described

Steps S 18a to Al 8c make it possible to output a target value F _FP representing an accelerator pedal restoring force with which the active accelerator pedal presses against the driver's foot to signal the driver to deflect the accelerator pedal 5 less than he currently does to the driver existing collision hazard calculated according to step S 17. In the subsequent step S19, it is checked whether the Driver reacts by an accelerator pedal operation or a brake pedal operation on the existing risk of collision and wants to override the system by a strong acceleration request or a strong deceleration request and thus would like to override the collision warning and avoidance device. If it has been detected in step S19 that driver override exists, then step S19 branches off, yes, and the method is ended in step S20, so that a normal driving operation is transited. If it is detected in step S19 that there is no driver override request, then branches Step S 19 to "no" and the method jumps back to step S 15, where it is checked again whether the activation condition exists that the own vehicle _speed V _{Fzg may} not be greater than the predetermined limit speed v _limit and the process again is set so that the output values for the implementation of the actions according to steps S 18a to S18d on the new traffic situation with newly read measured values d, v _rel , α _F p, α _B p can be adjusted.

Claims

08.06.2005 Hc / GkROBERT BOSCH GMBH, 70442 Stuttgart claims

1. A device for avoiding rear-end collisions when starting behind a preceding vehicle, wherein by means of an aligned in the vehicle apron environment sensor (3) the distance (d) and / or the speed (vrel) is determined to the preceding vehicle and in the presence of a starting situation a Driver-actuated longitudinal dynamic specification (α _F p, α _B p) is evaluated whether a risk of collision of the own vehicle with the vehicle ahead, characterized in that in the presence of a risk of collision in the drive train (10) and / or the deceleration devices (11) of the vehicle is intervened to reduce the risk of collision and / or driver warning devices (12.5) are controlled to inform the driver about the risk of collision.

2. Apparatus according to claim 1, characterized in that a

Starting situation by pressing the accelerator pedal by the driver, is detected.

3. Apparatus according to claim 1 or 2, characterized in that a

Anfahrsituation is only detected if the own vehicle speed (v _Fzg ) is below a predetermined limit speed (v _limit ).

4. Device according to one of the preceding claims, characterized in that the environment sensor (3) an ultrasonic sensor, a radar sensor, a

Lidarsensor, a video sensor or a combination of these types of sensors is.

5. Device according to one of the preceding claims, characterized in that the driver-actuated longitudinal dynamic specification is an accelerator pedal operation (α _F p) and / or releasing the brake pedal (α _B p).

6. Device according to one of the preceding claims, characterized in that the intervention in the drive train (10) of the vehicle is effected by a change in the accelerator pedal characteristic.

7. Device according to one of the preceding claims, characterized in that the intervention in the deceleration means (11) takes place by an automatic brake pressure build-up to complicate a collision-hazardous, driver-actuated starting.

8. Device according to one of the preceding claims, characterized in that the engagement in the deceleration means (11) is effected by an automatic brake pressure build-up to prevent a rolling back of the own vehicle on a slope.

9. Device according to one of the preceding claims, characterized in that the driver warning (5) by means of an accelerator pedal (5) with electrically controllable restoring force (F _FP ), wherein at an increased risk of collision, the restoring force (F _FP ) of the accelerator pedal is increased.

10. Device according to one of the preceding claims, characterized in that the driver warning device (12) is an acoustic signaling device.

11. Device according to one of the preceding claims, characterized in that the driver by an accelerator pedal override (5) can deactivate the collision avoidance function.

12. Device according to one of the preceding claims, characterized in that the collision avoidance function only below an upper

Limit speed (V _Gr enz) is active.

13. Device according to one of the preceding claims, characterized in that the collision avoidance function by a driver intervention in the drive train (10) by overdriving the accelerator pedal (α _F p) and / or a Driver intervention in the deceleration devices by pressing the brake pedal (α _B p) is disabled.

14. A method for avoiding rear-end collisions when starting behind a preceding vehicle, wherein depending on the distance (d) and / or the

Speed (vrel) to the preceding vehicle, which is determined by means of an environment sensor (3), and evaluated in the presence of a starting situation, a driver-actuated longitudinal dynamic specification, if there is a risk of collision of the own vehicle with the preceding vehicle, characterized in that in the presence of a risk of collision in the drive train (10) and / or the deceleration devices (11) of the vehicle is intervened to reduce the risk of collision and / or a driver warning (12, 5) is issued to inform the driver about the risk of collision.