Driver Assistance System for a Motor Vehicle

Abstract

A driver assistance system for automated longitudinal guidance of a motor vehicle includes a sensor system configured to identify an upcoming traffic scene, including locating road users situated ahead of the motor vehicle; and a control unit. The control unit is configured to carry out an automated longitudinal guidance of the motor vehicle depending on the upcoming traffic scene such that, in response to detecting that the upcoming traffic scene is a following-travel standstill situation, the motor vehicle is braked to a standstill at a target stopping distance from a road user situated ahead and identified as a target object. The control unit is also configured to detect a manual request to reduce the predefined target stopping distance. The control unit is further configured to reduce the target stopping distance to a reduced target stopping distance on the basis of the request.

Claims

1-9. (canceled)

10. A driver assistance system for automated longitudinal guidance of a motor vehicle, comprising: a sensor system configured to identify an upcoming traffic scene, including locating road users situated ahead of the motor vehicle; and a control unit configured to: carry out an automated longitudinal guidance of the motor vehicle depending on the upcoming traffic scene such that, in response to detecting that the upcoming traffic scene is a following-travel standstill situation, the motor vehicle is braked to a standstill at a target stopping distance from a road user situated ahead and identified as a target object, and detect a manual request to reduce the predefined target stopping distance, and reduce the target stopping distance to a reduced target stopping distance on the basis of the request.

11. The driver assistance system of claim 10, wherein the control unit is configured to prompt the reduction in the target stopping distance to the reduced target stopping distance during the following-travel standstill situation, based on the reduced target stopping distance.

12. The driver assistance system of claim 10, wherein the control unit is configured to cancel the reduction in the target stopping distance when a predefined cancel condition is satisfied, wherein the predefined cancel condition includes: that the speed of the motor vehicle exceeds a predefined speed threshold.

13. The driver assistance system of claim 10, further comprising: an operating element configured to be actuated so as to trigger the manual request to reduce the predefined target stopping distance during the following-travel standstill situation when the motor vehicle is at the standstill.

14. The driver assistance system of claim 13, wherein the operating element is configured to request at least two different functionalities, and wherein the control unit is configured to assign the manual request to one of the functionalities, depending on the time and/or type of the actuation.

15. The driver assistance system of claim 13, wherein the operating element is configured to be actuated in at least two different types of actuation for manually requesting the reduction in the stopping distance, wherein, upon manual actuation in accordance with a first type of actuation, during the following-travel standstill situation when the motor vehicle is at the standstill, the target stopping distance is reduced by a predefined reduction distance, and wherein, upon manual actuation in accordance with a second type of actuation, during the following-travel standstill situation when the motor vehicle is at the standstill, the target stopping distance is continuously reduced over a duration of the actuation of the operating element in accordance with the second type of actuation.

16. The driver assistance system of claim 10, wherein an extent of the reduction in the target stopping distance is influenced by at least one of: a currently set driving mode, a road class of the road currently being traveled on, and an object class of the road user situated up ahead.

17. The driver assistance system of claim 10, wherein the predefined target stopping distance is reduced to the reduced target stopping distance based on the manual request to reduce the stopping distance, only when further requirements are met.

18. A method for automated longitudinal guidance of a motor vehicle, comprising the following steps: identifying an upcoming traffic scene, including: locating road users situated ahead; controlling an automated longitudinal guidance of the motor vehicle depending on the upcoming traffic scene, in response to identifying that the upcoming traffic scene is a following-travel standstill situation, the motor vehicle is braked to a standstill at a target stopping distance from a road user situated ahead and identified as a target object, detecting a manual request to reduce the stopping distance; and reducing the target stopping distance to a reduced target stopping distance on the basis of the request.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows a highly simplified construction of a driver assistance system serving as an example of at least one embodiment of the invention, and

[0027] FIG. 2 shows a possible configuration of a method according to at least one embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 shows a control unit SE as the central element of a driver assistance system for automated longitudinal guidance of a motor vehicle. In principle, the control unit SE is configured in such a way that, depending on the signals s of an environment detection sensor system S, the current speed v and the driver specifications fv (for example target speed) predefined by the driver by means of a manual input unit mEE, it transmits an acceleration signal a to a drive actuator system A and a deceleration signal b to a brake actuator system B in order to implement the driver specifications fv. The environment detection sensor system S is in this case configured in such a way that the upcoming traffic scene can be identified by means of a radar system and/or a camera system and thus in particular relevant traffic users situated up ahead can be identified.

[0029] The control unit SE is also designed to prompt braking of the motor vehicle at a predefined target braking distance from a road user situated up ahead and identified as a target object when a following-travel standstill situation, that is to say a traffic situation in which the motor vehicle provided with the driver assistance system has to be braked to a standstill on account of a road user situated up ahead, is detected.

[0030] The manual input unit mEE is designed, upon corresponding actuation of an operating element BE provided therefor, to request a reduction in the stopping distance from the target object as driver specification fv during a following-travel standstill situation when the motor vehicle is at a standstill. In this example, provision is made for the request fv to reduce the stopping distance to be able to take place in various modes. If there is a simple key press on the operating element BE provided therefor during a following-travel standstill situation when the motor vehicle is a standstill, this is evaluated as a request fv to reduce the stopping distance by a predefined extent or by a predefined reduction distance. If, instead of a simple key press, the operating element BE provided therefor is permanently actuated during a following-travel standstill situation when the motor vehicle is at a standstill, this is evaluated as a request fv to continuously reduce the stopping distance (until the operating element is released).

[0031] If the control unit SE detects a request fv to reduce the stopping distance, the control unit SE first prompts a reduction in the target stopping distance—depending on the type of request (simple key press or permanent actuation). On the basis of the reduced target stopping distance, the control unit SE then prompts a reduction in the current stopping distance to the now reduced target stopping distance by transmitting corresponding acceleration and/or braking signals a and b. If the reduction is prompted on the basis of a permanent actuation, the target stopping distance is reduced and the stopping distance associated therewith is respectively reduced to the new target stopping distance until the operating element BE is released. While the operating element BE is permanently actuated, the speed of the motor vehicle is decreased depending on the current distance as part of the reduction in the stopping distance to the new (continuously further reducing) target stopping distance. When a predefined minimum distance is reached, the vehicle stops depending on other requests.

[0032] A specific configuration of a possible configuration of the method according to the invention for automated longitudinal guidance of a motor vehicle, in particular for adjusting the stopping distance on the basis of a manual request by the driver, is now presented on the basis of the following description in relation to FIG. 2, wherein it is assumed that the control unit SE that is essential for reducing the stopping distance is accordingly designed to detect relevant input signals, to process these, to adjust the target stopping distance and to output an acceleration signal a and/or a braking signal b, determined in accordance with the adjusted target stopping distance, to the actuator system A and B for the purpose of speed control.

[0033] The flow chart starts in step 10 as soon as the driver assistance system designed as an adaptive cruise control system is switched on and active. When the cruise control system is active, in the next step 20, the upcoming traffic scene is determined on the basis of the present data of an environment detection system. In particular, traffic objects situated up ahead that are to be taken into account in the cruise control are located. If a relevant traffic object situated up ahead is detected, automatic longitudinal guidance of the motor vehicle takes place depending on the upcoming relevant traffic object. If a following-travel standstill situation, that is to say a situation in which it is necessary to brake the vehicle to a standstill on account of the traffic object situated up ahead, is detected, the motor vehicle is braked to a standstill at a predefined target braking distance from the traffic object situated up ahead and identified as target object, and the method passes to step 30 upon the standstill being reached.

[0034] As long as the method is at step 30, that is to say automatic start-up or continuation of driving is not possible, a check is continuously carried out to determine whether a reduction in the stopping distance from the target object is manually requested by the driver (for example by way of actuating an operating element provided therefor) during the following-travel standstill situation at a standstill. If no such request is detected, step 30 is left and there is a return to step 10.

[0035] However, if such a manual request is detected, in the next step 40, the current target stopping distance is reduced by a predetermined—possibly variable—extent if there are no restraint conditions (for example minimum permitted target distance already set) on the basis of the manual request to reduce the stopping distance. The extent of the reduction can be specified in this case for example depending on the type of request by the driver, the road class of the road currently traveled on, the vehicle object class of the target object, a selected driving mode (sport, comfort, eco), the location of the road, the number of lanes and/or the lane width.

[0036] If the target stopping distance has been reduced, there is a change to step 50 in which a reduction in the stopping distance of the motor vehicle from the road user situated up ahead to the reduced target stopping distance is prompted on the basis of the reduced target stopping distance. In this case, the acceleration specification and/or the deceleration specification can be carried out in order to achieve or adjust the reduced target stopping distance according to a control strategy stored for this purpose. In this case, the control strategy may be able to be influenced in turn depending on other parameters, such that the vehicle is advanced in a comfortable and replicable manner.

[0037] A system of this kind is used to provide the driver with the opportunity to enable simple and comfortable automated advancement to a road user situated up ahead, without overdriving the active driving function.