METHOD FOR OPERATING A MOTOR VEHICLE HAVING A START-STOP SYSTEM, AND ASSOCIATED MOTOR VEHICLE

Abstract

A method for operating a motor vehicle with a start/stop system (2) for a combustion engine (4) of a motor vehicle (1) with a device (3) for detecting an area ahead of the vehicle, wherein the start/stop system (2) stops the combustion engine (4) if a speed of the motor vehicle (1) depending on at least one signal relating to the driving dynamic of the vehicle (1) falls below a limit value, wherein the combustion engine (4) is not stopped if a road unevenness that requires decelerated driving over is detected in the area ahead of the vehicle by means of the device for detecting the area ahead of the vehicle.

Claims

1. A method, comprising: operating a motor vehicle with a start/stop system for a combustion engine of a motor vehicle with a device for detecting an area ahead of the vehicle, wherein the start/stop system stops the combustion engine if a speed of the motor vehicle depending on at least one signal relating to the driving dynamic of the motor vehicle falls below a limit value, wherein the combustion engine is not stopped if a road unevenness that requires decelerated driving over is detected in the area ahead of the vehicle by means of the device for detecting the area ahead of the vehicle.

2. The method according to claim 1, wherein a speed bump placed on the road or a rail crossing the road is detected as a road unevenness.

3. The method according to claim 1, wherein the device detects the road unevenness based on cameras and/or by means of laser scanners and/or radars.

4. The method according to claim 1, wherein the motor vehicle comprises a control device, which analyzes the detected road unevenness by means of a pattern recognition algorithm, in particular by means of edge detection, and controls the entire start/stop system.

5. The method according to claim 1, wherein the road unevenness is checked for plausibility by means of at least one piece of information.

6. The method according to claim 5, wherein the information comprises predictive route data, preferable sign recognition data and/or position data of a GPS receiver or a navigation system.

7. The method according to claim 1, wherein a brake pressure and/or an acceleration of the motor vehicle is taken into consideration as a signal.

8. A motor vehicle, comprising: a start/stop system for a combustion engine with a device for detecting an area ahead of the vehicle, wherein the start/stop system is designed to stop the combustion engine if a speed of the motor vehicle depending on at least one signal relating to the driving dynamic of the motor vehicle falls below a limit value, wherein the start/stop system is designed to stop the combustion engine depending on a detected road unevenness in the area ahead of the vehicle.

9. The motor vehicle according to claim 8, wherein the device is designed to detect a speed bump placed on the road or a rail crossing the road as a road unevenness.

10. The motor vehicle according to claim 8, wherein the device is designed as a lidar, radar, camera, or laser scanner.

11. The motor vehicle according to claim 8, further comprising a control device that is designed to analyze the detected road unevenness by means of a pattern recognition algorithm, in particular by means of edge detection, and to control the entire start/stop system.

12. The motor vehicle according to claim 11, wherein to the control device, at least one piece of information for the plausibility check, in particular route data, sign detection data, or position data from a GPS receiver or a navigation system can be transmitted.

13. The motor vehicle according to claim 11, wherein the control device is designed to take into consideration as a signal a brake pressure and/or an acceleration of the motor vehicle.

Description

[0024] The invention is explained in the following by means of exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

[0025] FIG. 1 a lateral view of a motor vehicle according to the invention;

[0026] FIG. 2 a top view of the motor vehicle according to the invention of FIG. 1 in a first traffic situation;

[0027] FIG. 3 a top view of the motor vehicle according to the invention of FIG. 1 in a second traffic situation; and

[0028] FIG. 4 a flow diagram of the method according to the invention.

[0029] FIG. 1 shows a motor vehicle 1 with a start/stop system 2 and a device 3 for detecting an area ahead of the vehicle. The start/stop system 2 is designed to stop a combustion engine 4 if a speed of the motor vehicle 1 depending on at least one signal relating to the driving dynamic of the motor vehicle 1 falls below a limit value. For this purpose, the start/stop system 2 is connected to a control device 5, to which the signal of appropriate sensors is transmitted, such as a pedal sensor, which detects the pedal path of the brake pedal. The device 3, which is disposed at the front of the motor vehicle 1, is designed to detect a road unevenness in the area ahead of the vehicle. FIG. 1 shows that a speed bump 6 is depicted in the area ahead of the motor vehicle 1. This speed bump is detected by the device 3, which is illustrated by the dotted lines 7. The speed bump 6 detected by the device 3 is analyzed by the control device 5 by means of an algorithm for edge detection. Based on the speed bump 6, which is detected as a road unevenness and which only requires a reduction of the speed, but for which a turning off of the combustion engine 4 is not desired, the control device 5 controls the start/stop system 2 such that the combustion engine 4 is not stopped, if the driver reduces the speed to below a limit value (e.g., from the interval between 2-20 km/h) in order to drive over the speed bump 6.

[0030] FIG. 2 shows the motor vehicle 1 of FIG. 1 in a top view of a situation similar to that in FIG. 1. In the area ahead of the motor vehicle 1 is a speed bump 8, which is designed as a plateau with ramps. Markings 9 are attached to the ramps of the speed bump 8, which are to improve the visibility of the speed bump for a driver.

[0031] These markings 9 can be detected based on videos by the device 3, which also comprises a camera in addition to a laser scanner. This is illustrated by the dotted lines 10. The markings 9 detected by the device 3 are analyzed by the control device 5 by means of a pattern recognition algorithm. The start/stop system 2 is subsequently controlled accordingly by the control device 5 so that the combustion engine 4 is not stopped. In front of the speed bump 8, a traffic sign 11 is disposed at the roadside. This traffic sign is also detected by the device 3 based on videos for plausibility purposes. This is illustrated by the dotted lines 12. The detected traffic sign is identified as a traffic sign by the control device 5 by means of a sign recognition algorithm. Since the traffic sign 11 indicates a traffic-calmed area and the markings 9 were also detected, the speed bump 8 is considered to be plausible. A stopping of the combustion engine 4 by the start/stop system 2 is prevented by the control device 5.

[0032] FIG. 3 shows a top view of the motor vehicle 1 in front of a railroad crossing 13. In this case, the detection device 3 detects the rails 14 by means of laser scanners. The detection of the rails 14 by the device 3 is in this case illustrated by the dotted lines 17. The detected data are analyzed as rails by the control device 5 by means of an edge detection algorithm. In addition to the rails 14, the device 3 detects at the roadside the St. Andrew's cross 15, which indicates a right of way of the rail traffic. The detection of the traffic sign 15 is in this case indicated by the lines 16. The control device 5 can analyze the traffic sign 15 by means of the sign recognition algorithm and thus obtains as result a plausibility check that the previously analyzed rails 14 were correctly detected as such. It is also possible that it is detected from map data from a navigation system of the motor vehicle 1 that the railroad track crosses the lane, forming the railroad crossing 13. This information may also be transmitted to the control device 5 and thus be drawn upon for the plausibility check. Based on the thus correctly detected railroad crossing 13, falling below the speed limit value will not result in the combustion engine 4 being turned off, but the control device 5 will control the start/stop system 2 such that a stopping of the combustion engine 4 is prevented.

[0033] FIG. 4 shows a flow diagram of a method for operating a start/stop system 2 for a combustion engine 4 of a motor vehicle 1 with a device 3 for detecting an area ahead of the vehicle, wherein the start/stop system 2 stops the combustion engine 4 if a speed of the motor vehicle 1 depending on at least one signal relating to the driving dynamic of the motor vehicle 1 falls below a predefined limit value or a limit value parameterizable by the driver.

[0034] The method starts in block 18 with the detection of the area ahead of the motor vehicle 1 by the device 3. The data acquired in this way are analyzed in block 19 by the control device 5. In doing so, it is determined whether a road unevenness is present in the acquired data. This is performed by means of pattern recognition algorithms, sign detection algorithms, and the like. If no road unevenness is detected in block 19, it is branched back to block 18, in which the area ahead of the vehicle is continued to be detected. If a road unevenness was analyzed in block 19 by the control device 5, it can be checked in block 20 whether the presence of a road unevenness is plausible. If this is not the case, a rail was, for example, incorrectly identified in an area, in which a railroad track does not cross the road according to the data of a navigation system, and it is branched back again from block 20 to block 18, in which the area ahead of the vehicle is detected. A prevention of the stopping of the combustion engine 4 by the control device 5 does not take place in this case.

[0035] If the driver reduces the speed of the motor vehicle 1 in this area, the start/stop system 2 stops the combustion engine 4 the speed of the motor vehicle 1 falls below the limit value. If, based on the optional plausibility check in block 20, the road unevenness detected in block 19 proves to be plausible, it is branched to block 21, in which the control device 5 controls the start/stop system 2 such that a stopping of the combustion engine 4 is prevented. Subsequently, it is branched back from block 21 to block 18, in which the detection of the area ahead of the vehicle takes place. A continuous method is thus specified, which can however also be performed in defined intervals.