OPERATING METHOD AND SYSTEM FOR SUPPORTING LANE KEEPING OF A VEHICLE

• US 20100191421A1
• Filed: 08/15/2007
• Published: 07/29/2010
• Est. Priority Date: 08/15/2007
• Status: Active Grant

• Current Assignee: Volvo Truck Corporation (AB Volvo)
• Original Assignee: Volvo Technology Corporation
• Inventors: Nilsson, Jonas
• Granted Patent: US 8,428,821 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2050/0026 Lookup tables or parameter maps
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2420/408 Radar; Laser, e.g. lidar
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence

Abstract

A system and an operating method are provided for supporting lane keeping of a vehicle equipped with a steering device. The system and operating method include providing vehicle related information; providing environment related information; combining vehicle and environment related information; predicting a future trajectory of the vehicle based on vehicle and environment related information; estimating a desired lateral lane position of the vehicle and/or a guiding force; comparing the future trajectory and the desired lateral lane position; deciding if a guiding force is to be provided to the steering device; and, if guiding force is to be provided, defining an amount of said guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, adapting the amount of guiding force depending on the direction in which the vehicle is intended to move and activating one or more actuators for supplying the adapted amount of guiding force to the steering device.

Claims

1. An operating method for supporting lane keeping of a vehicle equipped with a steeling device, comprising

providing vehicle related information;

providing environment related information;

combining vehicle and environment related information;

predicting a future trajectory of the vehicle based on vehicle and environment related information;

estimating a desired lateral lane position of the vehicle and/or a guiding force;

comparing the future trajectory and-the-desired lateral lane position;

deciding if a guiding force is to be provided to the steering device; and

if guiding force is to be provided,

a) defining an amount of the guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle,

b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and

c) activating one or more actuators for supplying the adapted amount of guiding force to the steering device.

2. The method according to claim 1;

wherein the predetermined driving behavior is prioritized in the order of

stabilizing the vehicle;

preventing the vehicle from leaving the lane;

supporting the turning of the vehicle when travelling a curved trajectory along a bend.

3. The method according to claim 1, comprising using at least one of a lateral displacement, a lateral velocity, a lateral acceleration of the vehicle and a curvature of the road as input variables of the predetermined driving behavior.

4. The method according to claim 1, comprising adapting the amount of guiding force depending on the direction in which the vehicle is intended to move.

5. The method according to claim 1, comprising determining the amount of guiding force by at least one of an expert system, artificial intelligence system, fuzzy logic system.

6. The method according to claim 1, wherein for driving on a straight road the guiding force is adapted to increase if the lateral velocity of the vehicle increases when the vehicle is laterally moving away from the desired lateral position.

7. The method according to claim 1, herein for driving on a straight road the guiding force 4s-adapted-according to desired driving conditions and/or a desired state of the vehicle.

8. The method according to claim 1, wherein when moving towards a desired lateral position the guiding force is negative if the actual lateral velocity is below the actual desired lateral velocity, positive if the actual lateral velocity is above the actual desired lateral velocity, and zero if the actual lateral velocity is equal or almost equal to the actual desired lateral velocity.

9. The method according to claim 1, wherein when moving towards a desired lateral position the desired lateral velocity is at least a function of time and/or lateral deviation from the desired lateral position and/or curvature of the road or lane.

10. The method according to claim 9, wherein the desired lateral velocity is a function with a maximum and two inflection points on each side of the maximum, the inflection points preferably each having a value equal to or almost equal to zero.

11. The method according to claim 1, wherein the guiding force increases or decreases a resistance of the steering device counteracting the force exerted by the driver onto the steering device.

12. The method according to claim 1, wherein the guiding force always counteracts the actions of the driver when moving the vehicle away from a desired position and/or a desired state of the vehicle.

13. The method according to claim 1, wherein the guiding force is triggered only when moving the vehicle away from a desired position and/or a desired state of the vehicle.

14. The method according to claim 1, wherein for travelling a curved trajectory along a bend the guiding force towards an inside of the bend is different to the guiding force towards an outside of the bend.

15. The method according to claim 14, wherein for travelling a curved trajectory along a bend the guiding force towards an inside of the bend is adapted to be greater than for an equivalent situation on a Straight road.

16. The method according to claim 14, wherein for following a curved trajectory along a bend the guiding force towards an outside of the bend is adapted to be lower than for an equivalent situation on a straight road.

17. The method according to claim 1, comprising providing object data fusion and lane data fusion for environment related information.

18. The method according to claim 1, comprising providing at least one of wheel speed data, yaw rate data and steering wheel angle data as vehicle related information.

19. The method according to claim 1, wherein the lane keeping support system and/or a lane departure warning system is/are disabled when, and during the period of time, the vehicle is intentionally moved away from the desired lateral position.

20. The method according to claim 1, wherein with a trailer attached to the vehicle, the desired lateral position for the vehicle following a curved trajectory along a bend is estimated dependent on the desired lateral position of the trailer.

21. The method according to claim 20, wherein the desired lateral position of the vehicle is shifted towards an outside of the bend compared to the lateral position of the trailer.

22. The method according to claim 20, wherein the lane keeping support system and/or a lane departure warning system is/are disabled when, and during the period of time, the vehicle is leaving the lane on the outside if the trailer is predicted to stay at, or leave the lane on, the inside of the bend.

23. The method according to claim 1, wherein guiding force is provided depending on a classification of the road.

24. The method according to claim 23, wherein in case the probability that an adjacent lane exists exceeds a predefined threshold and it is decided to provide a guiding force to prevent a lane departure in that direction, the guiding force is chosen to be lower than in case no adjacent lane is present.

25. The method according to claim 23, wherein at a road border with no adjacent lane the guiding force is higher in direction of the road border.

26. The method according to claim 1, wherein in case of a lane departure when travelling along a bend in lateral direction towards the road centre, a guiding force is determined according to traffic conditions.

27. The method according to claim 26, wherein the guiding force is provided depending on expected oncoming traffic.

28. The method according to claim 26, wherein the guiding force is provided depending on expected overtaking traffic.

29. The method according to claim 1, wherein a lane departure warning and/or a guiding force is enabled when the predicted time to a lane departure is less than a variable threshold.

30. The method according to claim 29, wherein the variable threshold is a function of the magnitude of the lateral velocity of the vehicle, and that the variable threshold preferably increases with increasing lateral velocity of the vehicle.

31. A lane keeping system of a vehicle equipped with a steering device, particularly a steering wheel, for performing the method according to at least one of the preceding claims, comprising a support unit comprising a data fusion module for producing environment related information, a trajectory predictor module for predicting a future trajectory of the vehicle—

an estimator module for estimating a desired lateral lane position of the vehicle and/or a guiding force, and a decision system module for deciding if a guiding force should be provided and, if to be provided, for defining an amount of such guiding force depending on a hierarchically ordered set describing a predetermined driving behavior of the vehicle, and adapting the amount of guiding force depending on the direction in which the vehicle is intended to move, and activating one or more actuators for supplying the adapted amount of guiding force to the steering device, with one or more inputs for sensor data for the data fusion module, an input for vehicle related data and one or more outputs for an output of guiding force demand and/or warning signal.

32. The system of claim 31, comprising an electric motor for providing a guiding force to a steering device, particularly steering wheel of the vehicle.

33. A computer readable medium comprising a software code adapted to perform a method or for use in a method according to claim 1.

34. The computer readable medium according to claim 33 a downloaded to a computer which is connected to the internet.

35. A computer programmed with software code for use in a method according to claim 1.

36. A computer readable medium comprising a computer program product, the computer readable, program product comprising a program code for use in a method comprising at least the steps of

combining vehicle and environment related information;

predicting a future trajectory of the vehicle based on vehicle and environment related information;

estimating a desired lateral lane position and/or a guiding force;

comparing the future trajectory and the desired lateral lane position;

deciding if a guiding force is to be provided to the steering device; and

if guiding force is to be provided,

a) defining an amount of the guiding force depending-on a hierarchically ordered set describing a predetermined driving behavior of the vehicle;

b) adapting the amount of guiding force depending on the direction in which the vehicle is intended to move.

37. The computer readable medium according to claim 36, wherein the method further comprises the step of activating one or more actuators for supplying the adapted amount of guiding force to the steering device.