METHOD AND SYSTEM FOR DETECTING STEERING WHEEL CONTACT

• US 20140371989A1
• Filed: 06/12/2014
• Published: 12/18/2014
• Est. Priority Date: 06/13/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: TRIMBOLI, Sergio, HAUSE, Ronny
• Granted Patent: US 9,840,275 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60W 40/09 Driving style or behaviour
• CPC Class Codes: B62D 6/10 characterised by means for sensing or determining torque

Abstract

In accordance with various exemplary embodiments, the present disclosure describes methods and systems for detecting steering wheel contact by a user. A test signal may be transmitted to a power assisted steering system of a vehicle, where the test signal may apply torque to the steering wheel of the vehicle. A torque sensor may then receive measurements signals indicative of steering wheel torque. The torque indicated by the measurement signals may be compared to an expected torque. Based on the comparison, it may be determined whether the user is in contact with the steering wheel.

Claims

1. A method for detecting steering wheel contact by a user, the method comprising:

transmitting a test signal to a power assisted steering system of a vehicle that applies torque to a steering wheel of the vehicle based on the test signal;

receiving, from a torque sensor, measurement signals indicative of steering wheel torque by a user;

comparing the torque indicated by the received measurement signals to an expected torque based on measurement signals received from the vehicle prior to transmitting the test signal; and

determining whether a user is in contact with the steering wheel based on the comparison.

2. The method of claim 1, wherein a manager performs the comparing and determining steps.

3. The method of claim 2, wherein the manager uses at least one of a neural network work, a spectral transformation, and a statistical filter to determine whether the user is in contact with the steering wheel.

4. The method of claim 1, wherein the torque indicated by the received measurement signals comprises a reaction torque representative of steering wheel torque from the user in response to the test signal.

5. The method of claim 1, further comprising:

determining that the user is in contact with the steering wheel when a difference between the torque indicated by the received measurement signals and the expected torque meets a criteria.

6. The method of claim 1, wherein the torque applied to the steering wheel based on the test signal comprises an amplitude which is selected such that a change in a steering wheel angle during operation of the vehicle remains smaller than a threshold angle.

7. The method as claimed in claim 1, wherein the transmission of the test signal and the torque applied to the steering wheel are terminated after a predetermined period of time has elapsed.

8. A system for detecting steering wheel contact by a user, the system comprising:

a vehicle;

a power assisted steering system that comprises a torque sensor and a steering wheel, wherein torque is applied to the steering wheel based on receipt of a test signal by the power assisted steering system; and

a manager configured to;

receive, from the torque sensor, measurement signals indicative of steering wheel torque by a user;

compare the torque indicated by the received measurement signals to an expected torque based on measurement signals received from the vehicle prior to transmitting the test signal; and

determine whether a user is in contact with the steering wheel based on the comparison.

9. The system of claim 8, wherein the manager uses at least one of a neural network work, a spectral transformation, and a statistical filter to determine whether the user is in contact with the steering wheel.

10. The system of claim 8, wherein the torque indicated by the received measurement signals comprises a reaction torque representative of steering wheel torque from the user in response to the test signal.

11. The system of claim 8, wherein the manager is further configured to:

determine that the user is in contact with the steering wheel when a difference between the torque indicated by the received measurement signals and the expected torque meets a criteria.

12. A method for detecting a state of steering wheel contact, the method comprising:

generating a test signal;

applying torque in accordance with the test signal to a power-assisted steering system by an electric servomotor of the power-assisted steering system;

measuring steering wheel torque;

supplying the test signal and the measured steering wheel torque signal as measurement variables to a manager, the manager being configured to model a steering wheel system and to detect steering wheel contact using differences between the measurement variables and the modeled steering wheel system; and

outputting a status variable of the modeled steering wheel system, the status variable comprising the state of the steering wheel contact.

13. The method as claimed in claim 12, in which the manager applies a spectral transformation or a statistical filter method to the measurement variables, or contains a neural network.

14. The method as claimed in claim 12, wherein the vehicle measurement signals are also supplied to the manager as measurement variables.

15. The method as claimed in claim 12, wherein the measurement variables are stored by the manager.

16. The method as claimed in claim 12, wherein the test signal is generated and torque is applied to the power-assisted steering system based on a triggering signal.

17. The method as claimed in claim 12, wherein the torque applied to the power-assisted steering system has an amplitude which is selected such that a change in a steering wheel angle during operation of a vehicle remains smaller than a threshold angle.

18. The method as claimed in claim 12, wherein the generation of the test signal and the torque applied to the power-assisted steering system are terminated after a predetermined period of time has elapsed.

19. A computer readable storage medium storing program code which, when executed by a processor, performs the steps of:

transmitting a test signal to a power assisted steering system of a vehicle that applies torque to a steering wheel of the vehicle based on the test signal;

receiving, from a torque sensor, measurement signals indicative of steering wheel torque by a user;

comparing the torque indicated by the received measurement signals to an expected torque based on measurement signals received from the vehicle prior to transmitting the test signal; and

determining whether a user is in contact with the steering wheel based on the comparison.