SYSTEMS, METHODS AND DEVICES FOR ADAPTIVE STEERING CONTROL OF AUTOMOTIVE VEHICLES

• US 20090299573A1
• Filed: 05/27/2008
• Published: 12/03/2009
• Est. Priority Date: 05/27/2008
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Levinson, Jesse S., Thrun, Sebastian
• Granted Patent: US 8,392,064 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• 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

Abstract

A variety of methods, systems, devices and arrangements are implemented for automated assistance for a driver. One such method relates to a synergistic combination of automation and human control for a motor vehicle traveling on a lane, thereby allowing human-based decisions to be supplement (or be supplemented by) automated decisions. Specific aspects facilitate maintenance of the vehicle on the lane. The vehicle is automatically steered towards a lateral offset within the vehicle lane. Steering input from the driver results in changes to this lateral offset. This modification of the lateral offset can be used to allow the driver to follow any trajectory parallel to the road, including trajectories where the vehicle is not centered within the lane.

Claims

1. A method for providing automated assistive steering of an automotive vehicle to maintain the vehicle within a vehicle lane by providing automated assistive steering relative to a target vehicle offset, the method comprising:

modifying, in response to steering input from a driver, the target vehicle offset and thereby maintaining the vehicle along a new path in the vehicle lane.

2. The method of claim 1, further including the step of trimming vehicle tires as a function of the modified target vehicle offset and without modifying a position of a steering device, that allows a driver to provide the steering input.

3. The method of claim 1, wherein the steering input from the driver includes the driver turning a steering wheel and subsequently straightening the steering wheel, thereby steering the vehicle along the new path.

4. The method of claim 1, further including the step of trimming tires of the vehicle to maintain the modified target vehicle offset.

5. The method of claim 1, further including the step of trimming tires of the vehicle to maintain the modified target vehicle offset while the vehicle lane exhibits a curve that is a sufficiently sharp angle that the vehicle would leave the lane without trimming tires of the vehicle.

6. The method of claim 1, further including the step of providing an indication to a driver of the vehicle of what the target vehicle offset is relative to the lane.

7. The method of claim 1, further including the step of detecting the vehicle lane using one or more of an optical camera, a laser, an inertial measurement unit, a tire odometer and a global positioning system (GPS) receiver.

8. The method of claim 1, wherein the steering input from a driver is provided using a drive-by-wire steering system.

9. The method of claim 1, further including the step of trimming tires of the vehicle to maintain the modified target vehicle offset as a function of one or more of vehicle speed, vehicle heading, road curvature, vehicle types and calibration parameters.

10. A method for providing automated assistive steering of an automotive vehicle to maintain the vehicle at a target vehicle offset within a vehicle lane, the method comprising:

setting, in response to a driver steering input, the target vehicle offset within the vehicle lane as a function of a current vehicle-position signal; and

generating, in response to an error between the current vehicle-position and the target vehicle offset, a steering trim-adjust signal to facilitate automatic assistive steering for the automotive vehicle.

11. The method of claim 10, further including the steps of:

sensing the actual position of the vehicle to provide the current vehicle-position;

determining the error between the current vehicle-position and the target vehicle offset; and

using the steering trim-adjust signal to direct the steering controller and thereby maintain the vehicle within a vehicle lane as a function of the target vehicle offset.

12. The method of claim 10, wherein the current vehicle-position is used to maintain the vehicle in a forward-moving lateral position in the vehicle lane;

and redirecting the steering controller, in response to a subsequent driver steering input, to facilitate an effort to maintain the vehicle in a different forward-moving lateral position in the vehicle lane.

13. The method of claim 10, wherein the modified target vehicle trajectory corresponds to a non-zero offset from a center of the vehicle lane, whereby the non-zero offset is used to maintain the vehicle in a vehicle path that is substantially parallel to the center of the vehicle lane.

14. The method of claim 10, further including the step of detecting a driver steering input that indicates an override operation for the steering trim-adjust signal.

15. The method of claim 10, further including the step of determining the vehicle lane from a plurality of input sources.

16. The method of claim 10, further including the step of determining the vehicle lane based on:

a plurality of input sources; and

an average of outcomes generated by a plurality of vehicle lane prediction algorithms, each vehicle lane prediction algorithm using data from at least one of the plurality of input sources.

17. The method of claim 10, wherein the driver steering input is derived from a torque sensor that detects force exerted by the driver on a steering element.

18. The method of claim 10, further including the step of receiving an alert signal and, in response thereto, automatically generating a new steering trim-adjust signal to redirect the automotive vehicle out of the vehicle lane for safety.

19. The method of claim 10, wherein the step of generating a steering trim-adjust signal is a function of one or more of vehicle speed, vehicle heading, road curvature, vehicle types and calibration parameters.

20. The method of claim 19, further including the step of disabling the steering trim-adjust signal in response to determining that the steering trim-adjust signal has insufficient accuracy.

21. For automatic assistive steering of an automotive vehicle operating in a vehicle lane with the vehicle operating responsive to manually-controlled driver steering forces, a computer readable medium containing a set of computer-executable instructions that, when executed, causes a computer in the automotive vehicle to:

set, in response to a driver steering input, a target vehicle offset that indicates a lateral position within the vehicle lane as a function of a current vehicle-position; and

generate, in response to an error between the current vehicle-position and the target vehicle offset, a steering trim-adjust signal to facilitate automatic assistive steering for the automotive vehicle.

22. The computer readable medium of claim 21, wherein the driver steering input is responsive to the driver turning a steering wheel and subsequently straightening the steering wheel, thereby placing the vehicle at the lateral position within the vehicle lane.