SYSTEM AND METHOD FOR SMOOTH STEERING OVERRIDE TRANSITION DURING AUTOMATED LANE CENTERING

• US 20130060414A1
• Filed: 09/02/2011
• Published: 03/07/2013
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: LEE, Jin-Woo, Litkouhi, Bakhtiar Brian
• Granted Patent: US 9,073,576 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/087 using active steering actuation
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 40/08 related to drivers or passengers
• CPC Class Codes: B62D 1/286 Systems for interrupting non-mechanical steering due to 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 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00

Abstract

Vehicle steering measurements of a vehicle may be measured. Expected vehicle steering measurements may be calculated, each calculated expected vehicle steering measurement corresponding to one of the measured vehicle steering measurements. At least one difference between one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement may be calculated. A lower boundary and an upper boundary of at least one override transition zone, each of the override transition zones corresponding to one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement, may be calculated. Steering control of the vehicle may be gradually transferred from an automatic vehicle control system to a driver of the vehicle over a predetermined period of time when one or more of the calculated differences lie between the calculated lower boundary and the calculated upper boundary of the corresponding override transition zone.

Claims

1. A method comprising:

measuring one or more vehicle steering measurements of a vehicle;

calculating one or more expected vehicle steering measurements, each calculated expected vehicle steering measurement corresponding to one of the measured vehicle steering measurements;

calculating at least one difference between one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement;

calculating a lower boundary and an upper boundary of at least one override transition zone, each of the override transition zones corresponding to one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement; and

transferring steering control of the vehicle from an automatic vehicle control system to a driver of the vehicle over a predetermined period of time when one or more of said at least one calculated difference lies between the calculated lower boundary and the calculated upper boundary of the corresponding override transition zone.

2. The method of claim 1, wherein the calculated lower boundary or the calculated upper boundary declines in value as a measured speed of the vehicle increases.

3. The method of claim 1, wherein the one or more vehicle steering measurements comprises a vehicle steering angle measurement.

4. The method of claim 1, wherein the one or more vehicle steering measurements comprises a vehicle steering torque measurement.

5. The method of claim 1, wherein the period of time is selected such that a characteristic of motion of the vehicle does not deviate from a predetermined vehicle motion criterion.

7. The method of claim 1, wherein the steering control by the automatic vehicle control system is reduced in accordance with an exponential function of time.

8. The method of claim 1, wherein the vehicle automated steering system comprises an adaptive lane centering system.

9. The method of claim 1, comprising providing an alert prior to transferring steering control.

6. The method of claim 6, wherein the predetermined motion criterion comprises an upper limit on lateral acceleration or an upper limit on yaw acceleration.

10. A system comprising:

a vehicle automated steering system;

one or more sensors; and

a controller to;

measure one or more vehicle steering measurements of a vehicle;

calculate one or more expected vehicle steering measurements, each calculated expected vehicle steering measurement corresponding to one of the measured vehicle steering measurements;

calculate at least one difference between one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement;

calculate a lower boundary and an upper boundary of at least one override transition zone, each of the override transition zones corresponding to one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement; and

transfer steering control of the vehicle from an automatic vehicle control system to a driver of the vehicle over a period of time when one or more of said at least one calculated difference lies between the calculated lower boundary and the calculated upper boundary of the corresponding override transition zone.

11. The system of claim 10, wherein the calculated lower boundary or the calculated upper boundary declines in value as a measured speed of the vehicle increases.

12. The system of claim 10, wherein the one or more vehicle steering measurements comprises a steering angle measurement.

13. The system of claim 10, wherein the one or more vehicle steering measurements comprises a steering torque measurement.

14. The system of claim 10, wherein the vehicle automated steering system comprises an adaptive lane centering system.

15. The system of claim 10, wherein the controller provides an alert prior to transferring steering control.

16. The system of claim 10, wherein the period of time is selected such a characteristic of motion of the vehicle does not deviate from a predetermined vehicle motion criterion.

17. The system of claim 16, wherein the predetermined motion criterion comprises an upper limit on lateral acceleration or an upper limit on yaw acceleration.

18. The system of claim 11, wherein the sensors comprise a sensor for measuring a speed of the vehicle.