METHOD FOR AUTOMATIC LANE GUIDANCE SYSTEM LANE GUIDANCE SYSTEM FOR AUTOMATIC LANE GUIDANCE OF A VEHICLE

Abstract

A method for automatically guiding a track of a vehicle which includes at least two wheels on each vehicle side and a track guidance system which is able to detect at least one lane groove within a driving lane, the method including influencing a track guidance of the vehicle as a function of a detection of the at least one lane groove, wherein the track guidance system includes a lane groove following mode in which the track guidance of the vehicle is influenced by the track guidance system after the at least one lane groove has been detected so that the vehicle follows the at least one detected lane groove in that at least two wheels at least at one vehicle side are caused to overlap the at least one detected lane groove.

Claims

1. A method for automatically guiding a track of a vehicle which includes at least two wheels on each vehicle side and a track guidance system which is able to detect at least one lane groove within a driving lane, the method comprising: influencing a track guidance of the vehicle as a function of a detection of the at least one lane groove, wherein the track guidance system includes a lane groove following mode in which the track guidance of the vehicle is influenced by the track guidance system after the at least one lane groove has been detected so that the vehicle follows the at least one detected lane groove in that at least two wheels at least at one vehicle side are caused to overlap the at least one detected lane groove.

2. The method according to claim 1, wherein the automatic track guidance of the vehicle is performed by the track guidance system as a function of detected vehicle environment parameters which differ from the at least one detected lane groove when no lane groove has been detected by the track guidance system or in a mode of the track guidance system that differs from the lane groove following mode.

3. The method according to claim 1, wherein the track guidance of the vehicle is influenced by the track guidance system when the track guidance system has detected two substantially parallel lane grooves within the driving lane, namely a first lane groove and a second lane groove, so that the vehicle follows the two substantially parallel lane grooves by causing at least two wheels on a first vehicle side to overlap with a first detected lane groove of the two substantially parallel lane grooves and causing at least two wheels on the second vehicle side to overlap with a second detected lane groove of the two substantially parallel lane grooves.

4. The method according to claim 1, wherein the track guidance system controls or regulates the vehicle in the lane groove following mode so that the vehicle only follows the at least one detected lane groove when the track guidance system has detected that the at least one detected lane groove is within a driving lane and the vehicle moves within lane boundaries of the driving lane when following the at least one detected lane groove.

5. The method according to claim 1, wherein the track guidance system is able to detect a wet driving surface in the lane groove following mode and wherein the track guidance system only influences the track guidance of the vehicle to follow the at least one detected lane groove when the track guidance system has not detected the wet driving surface.

6. A track guidance system able to automatically guide a track of a vehicle which includes at least two wheels on each vehicle side, the track guidance system comprising: a control or regulation device; a sensor device able to detect vehicle environment parameters and at least one lane groove within a driving lane among detected vehicle environment parameters wherein the sensor device generates lane groove detection signals when detecting the at least one lane groove and feeds the lane groove detection signals into the control or regulation device; at least one actuator controlled or regulated by the control or regulation device as a function of the detected vehicle environment parameters wherein the actuator influences a track guidance of the vehicle, wherein the control or regulation device is configured to control or regulate the at least one actuator as a function of the lane groove detection signals, wherein the track guidance system includes a lane groove following mode, wherein the control or regulation device is able to control or regulate the at least one actuator in the lane groove following mode when receiving the lane groove detection signals so that the vehicle follows the at least one detected lane groove by causing at least two wheels at least at one vehicle side to overlap with the at least one detected lane groove.

7. The track guidance system according to claim 6, configured so that in the event that the sensor device has not generated any lane groove detection signals or in a mode of the track guidance system that differs from the lane groove following mode, the control or regulation device controls the at least one actuator so that the track guidance of the vehicle is performed as a function of the vehicle environment parameters detected by the sensor device which differ from the at least one detected lane groove.

8. The track guidance system according to claim 6, configured so that in the event that the sensor device has detected two substantially parallel lane grooves within the driving lane, namely a first lane groove and a second lane groove, and corresponding lane groove detection signals have been fed to the control or regulation device, the control or regulation device controls the at least one actuator so that the vehicle follows the two detected substantially parallel lane grooves in that at least two wheels on a first side of the vehicle are caused to overlap with a first detected lane groove of the two detected substantially parallel lane grooves and at least two wheels on a second side of the vehicle are caused to overlap with a second detected lane groove of the two detected substantially parallel lane grooves.

9. The track guidance system according to claim 6, wherein the control or regulation device is configured to control or regulate the at least one actuator when the lane groove detection signals are received so that the vehicle only follows the at least one detected lane groove when the sensor device has detected that the at least one detected lane groove is within the driving lane and that the vehicle moves within lane boundaries of the driving lane when following the at least one detected lane groove.

10. The track guidance system according to claim 6, wherein the sensor device is configured to detect a wet driving surface and feed corresponding wet detection signals to the control or regulation device, wherein the control or regulation device controls or regulates the at least one actuator when simultaneously receiving the corresponding wet detection signals and the lane groove detection signals so that the wheels of the vehicle have an offset from the at least one detected lane groove.

11. The track guidance system according to claim 6, wherein the actuator includes a steering device or a braking device of the vehicle.

12. The track guidance system according to claim 6, wherein the sensor device includes an image capture device including at least one camera.

13. The track guidance system according to claim 6, configured so that that it performs semi-autonomous or autonomous track guidance of the vehicle.

14. The tack guidance system according to claim 6, wherein the lane groove following mode can be selected from a number of modes for tracking the vehicle.

15. A vehicle, comprising the track guidance system according to claim 6.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] An advantageous embodiment of the invention is described with reference to a drawing figure, wherein:

[0030] FIG. 1 illustrates a vehicle in an advantageous embodiment of a track guidance system according to the invention;

[0031] FIG. 2 illustrates a block diagram of an advantageous embodiment of a method for automatically guiding a track of the vehicle.

DETAILED DESCRIPTION OF THE INVENTION

[0032] FIG. 1 shows an EGO vehicle 100, configured with an advantageous embodiment of a track guidance system 4 according to the invention wherein the vehicle moves on a two-lane driving surface 1 with two driving lanes, a right driving lane 2 and a left driving lane 3, wherein the vehicle moves on the right driving lane 2, controlled partially autonomously or autonomously controlled e.g. by a control or regulation device 5. The track guidance system 4 is configured e.g. as an on-board system and arranged in its entirety on the EGO vehicle 100 and forms part of the partially autonomous or autonomous control/regulation of the ego vehicle 100. Alternatively, the track guidance system 4 can also be a distributed system wherein parts of the track guidance system 4 can also be arranged in an external unit.

[0033] The track guidance system 4 includes an image capture device 6 for a sensor device e.g. configured as a camera, in particular a stereo camera whose detection area is oriented forward from the EGO vehicle 100. The image capture device 8 continuously captures signals that are fed to the control or regulation device 5. Alternatively, or additionally, also one or plural other suitable sensor devices can be used which can detect vehicle environment parameters of the EGO vehicle 100.

[0034] The driving surface 1 includes two driving surface boundaries 7 which can also be e.g. a driving lane boundary of the right driving lane and the left driving lane 2,3. Additionally there is a dashed center line 8 arranged between the right and the left driving lane 2, 3 which also form a driving lane boundary of the right and the left driving lane 2, 3. The image capture device 6 can capture and detect the driving surface boundaries 7 and the center line 8 or the driving lane boundaries 7, 8. Furthermore the image capture device 6 is also capable to detect lane grooves 10, 11 on or in the driving surface 1 or on or in the currently driven driving lane 2 wherein the lane grooves are configured e.g. as indentations in the driving surface pavement.

[0035] Additionally, the image capture device 6 can detect additional vehicle environment parameters of the EGO vehicle 100 which define an environment of the EGO vehicle 100 like e.g. static or dynamic obstacles, objects or an additional preceding vehicle, distance, relative velocity, relative acceleration with respect to obstacles, objects and/or relative to the additional vehicle, traffic signs and light conditions in the environment of the EGO vehicle 100.

[0036] The control or regulation device 5 includes e.g. an auto pilot that is configured to control the EGO vehicle 100 partially autonomously or autonomously. The control or regulation device 5 determines e.g. a nominal drive trajectory for the EGO vehicle 100 along the right driving lane 2 as a function sensor signals put out by the image capture device 6. In particular, the control or regulation device 5 includes lane keeping logic and determines among other things a nominal steering angle configured to guide the EGO vehicle 100 along the nominal drive trajectory, thus within the right driving lane 2. This nominal steering angle is then fed to a steering device 9 of the EGO vehicle 100 so that steerable wheels of a steerable axle of the EGO vehicle 100 are aligned according to the nominal steering angle. The actual steering angle can then be determined e.g. by a steering angle sensor and regulated by the control or regulation device 5 to match the nominal steering angle.

[0037] The track guidance system 4 includes in particular a lane groove following mode that is selectable from plural modes wherein the lane groove following mode is selectable or activatable or deactivatable through a man machine interface like an operator console.

[0038] The image capture device 6 includes e.g. a processing algorithm which is configured in particular in lane groove following mode to detect a lane groove 10, 11 on or in the driving surface 1 and here in particular in or on the right driving lane 2 based on the sensor signals. When a lane groove 10, 11 is detected on or in the right driving lane 2, the image capture device 6 feeds lane groove detection signals into the control or regulations device 5 which then controls or regulates the steering device 9 in particular in lane groove following mode so that the EGO vehicle 100 follows the detected lane groove 10, 11 by causing two wheels on at least one vehicle side to overlap with the detected lane groove 10, 11.

[0039] In the other case when no lane groove 10, 11 is detected by the image capture device 6 in particular in lane groove following mode, the lane groove following mode is exited and the automatic track guidance of the EGO vehicle 100 is then performed e.g. by the track guidance system 4 based on captured vehicle environment parameters which differ from a detected lane groove 10, 11 and which are listed supra.

[0040] When two lane grooves, a right lane groove 10 and a left lane groove 11 are captured and detected as shown in FIG. 1 and if the track width of the EGO vehicle 100 essentially corresponds to a track width of the two lane grooves 10, 11 which can be captured and detected by the image capture device 6, the control or regulation device 5 can also control or regulate the steering device 9 so that the EGO vehicle 100 follows the detected lane grooves 10, 11 by causing two wheels on the right vehicle side to overlap with the captured right lane groove 10 and the two wheels on the left vehicle side are caused to overlap with the captured left lane groove 11. Track keeping logic of the track guidance system 4 guides the EGO vehicle 100 in view of its width and track width so that the EGO vehicle 100 is entirely kept in the right driving lane 2. If the lane groove 10 or 11 or the lane grooves lead towards an outside of the driving lane 2 which can occur when a path of the driving surface has been reconfigured or old lane grooves 10, 11 are still present in the driving lane a departure of the lane grooves 10, 11 from the driving surface is captured and detected by the image capturing device 6 and further following of the lane grooves 10, 11 by the control or regulation device of the EGO vehicle is prevented in that the lane groove following mode is automatically exited.

[0041] The advantageous track guidance system 4 includes an image capture device 6 capable of detecting a wet driving surface 1 and feeding corresponding wet detection signals to the control or regulation device 5. The control or regulation device 5 can be configured to control or regulate the steering device 9 when simultaneously receiving lane groove detection signals and wet detection signals so that the wheels, in this case the wheels on the right vehicle side and the wheels on the left vehicle side of the EGO vehicle 100 respectively have an offset from the two detected lane grooves 10, 11 so that a prevailing hydroplaning risk is mitigated. Alternatively the control or regulation device 5 can be configured to automatically exit the lane groove following mode when lane groove detection signals and wet detection signals are received simultaneously.

[0042] When the EGO vehicle 100 has been steered by the steering or regulation device 5, initially in dry weather conditions in the lane groove following mode so that the vehicle follows the two lane grooves 10, 11 but rain starts during the trip which makes the driving surface 1 wet, thus when there is a transition from a dry driving surface to a wet or humid driving surface 1 during the trip a nominal driving trajectory of the EGO vehicle 100 can be adjusted to that the wheels on the right vehicle side and the wheels on the left vehicle side of the EGO vehicle 10 respectively have an offset from the two detected lane grooves 10, 11 that are filled with water. Alternatively, the lane groove following mode can also be automatically exited in this situation. These exceptions, however, do not contradict the basic strategy that the EGO vehicle 100 should travel in lane groove following mode as a principle with at least two wheels of a vehicle side in a lane groove 10, 11.

[0043] FIG. 2 shows a flow chart of an advantageous embodiment of the method for automatic track guidance of the EGO vehicle 100 by the track guidance system 4 described supra. The method is implemented in an executable program which is stored e.g. in a memory of the control or regulation device 5.

[0044] In step 20, it is being checked whether the lane groove following mode has been activated e.g. by the man-/machine interface. If this is not the case. (no) the track guidance of the EGO vehicle 100 is performed by another mode of the track guidance system 4 according to step 70.

[0045] When this is the case (yes) it is being checked according to step 30 whether the image capture device 6 has detected a lane groove or plural lane grooves 10, 11 shown in FIG. 1 on or in the right driving lane 2. When this is not the case (no) the lane groove following mode is automatically terminated and the track guidance of the EGO vehicle 100 is performed by another mode of the track guidance system 4 according to step 70.

[0046] However, when this is the case (yes) the lane groove following mode is continued and it is being checked in step 40 whether the lane groove 10, 11 continues within the driving lane 2 or runs out of the driving lane 2. If it is determined that the lane groove 10, 11 runs out of the driving lane 2 (no) the lane groove following mode is automatically terminated and the track guidance of the EGO vehicle 100 is performed by another mode of the track guidance system 4 according to step 70.

[0047] However if this is the case (yes) this means the lane groove 10, 11 continues to run within the driving lane 2 the lane groove following mode is continued and it being checked in step 50 whether the driving surface is wet. If this is the case (yes) the image capture device has detected a wet driving surface 1 or driving lane 2 so that there is a hydroplaning risk and therefore the lane groove following mode is automatically terminated and subsequent track guidance of the EGO vehicle 100 is performed by another mode of the track guidance system 4 according to step 70.

[0048] If this is not the case (no) the image capture device has not detected a wet driving surface 1 or driving lane 2 or has detected a dry driving surface 1 or driving lane 2 so that there is no hydroplaning risk and therefore the lane groove following mode is continued so that the EGO vehicle 100 follows the detected lane groove 10, 11 in step 60. The sequence of steps 40 and 50 can certainly also be inverted.

REFERENCE NUMERALS AND DESIGNATIONS

[0049] 1 driving surface [0050] 2 right driving lane [0051] 3 left driving lane [0052] 4 track guidance system [0053] 5 control or regulation device [0054] 6 image capture device [0055] 7 driving surface boundary [0056] 8 center line [0057] 9 steering device [0058] 10 right lane groove [0059] 11 left lane groove [0060] 20-70 method steps [0061] 100 EGO vehicle