Method and system for detecting steering wheel contact

Patent metadata

Field	Value
Publication number	US-9840275-B2
Application number	US-201414303447-A
Country	US
Kind code	B2
Filing date	Jun 12, 2014
Priority date	Jun 13, 2013
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

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.

First claim

What is claimed is:

1. A method for detecting steering wheel contact, comprising:
transmitting a test signal to a power assisted steering system to initiate application of a test torque to a steering wheel over a period of time, the test signal comprising a sinusoidal wave with a frequency and amplitude an amplitude;
receiving, from a torque sensor, measurement signals indicative of actual steering wheel torque over the period of time;
comparing the actual torque to an expected torque to determine a phase shift in at least one of amplitude and frequency between the test signal and the received measurement signals; and
determining whether a user is in contact with the steering wheel based on the comparison and the determined phase shift.

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 actual torque comprises a reaction torque representative of steering wheel torque from the user in response to the test signal.

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

6. 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 a test torque is applied to the steering wheel based on receipt of a test signal to initiate application of the test torque by the power assisted steering system over a period of time, the test signal comprising a sinusoidal wave with a frequency and amplitude; and
a manager configured to:
receive, from the torque sensor, measurement signals indicative of actual steering wheel torque over the period of time;
compare the actual torque to an expected torque to determine a phase shift in at least one of amplitude and frequency between the test signal and the received measurement signals; and
determine whether a user is in contact with the steering wheel based on the comparison and the determined phase shift.

7. The system of claim 6 , 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.

8. The system of claim 6 , wherein the actual torque comprises a reaction torque representative of steering wheel torque from the user in response to the test signal.

9. A non-transitory 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 to initiate application of a test torque to a steering wheel over a period of time, the test signal comprising a sinusoidal wave with a frequency and amplitude an amplitude;
receiving, from a torque sensor, measurement signals indicative of actual steering wheel torque over the period of time;
comparing the actual torque to an expected torque to determine a phase shift in at least one of amplitude and frequency between the test signal and the received measurement signals; and
determining whether a user is in contact with the steering wheel based on the comparison and the determined phase shift.

10. The method of claim 1 , wherein the expected torque is based on signals indicative of actual steering wheel torque monitored prior to transmitting the test signal.

11. The method of claim 1 , further comprising:
monitoring measurement signals received from the torque sensor over a predetermined period of time prior to transmitting the test signal; and
storing the monitored measurement signals, wherein the expected torque is based on stored measurement signals.

12. The system of claim 6 , wherein the manager is further configured to:
monitor measurement signals received from the torque sensor over a predetermined period of time prior to transmitting the test signal; and
store the monitored measurement signals, wherein the expected torque is based on stored measurement signals.

13. The method of claim 1 , wherein an amplitude of the applied test torque is based at least in part on a lateral acceleration of the vehicle.

14. The system of claim 6 , wherein an amplitude of the applied test torque is based at least in part on a lateral acceleration of the vehicle.

15. A method for detecting steering wheel contact, comprising:
transmitting a test signal to a power assisted steering system to initiate application of a test torque to a steering wheel over a period of time, the test signal comprising a sinusoidal wave with a frequency and amplitude;
receiving, from a torque sensor, measurement signals indicative of actual steering wheel torque over the period of time;
determining a phase shift in at least one of amplitude and frequency between the test signal and the received measurement signals; and
determining whether a user is in contact with the steering wheel based on and the determined phase shift.

16. The method of claim 15 , wherein determining whether the user is in contact with the steering wheel based on the determined phase shift includes determining that the user is in contact with the steering wheel when a maximum phase shift threshold is exceeded.

17. The method of claim 1 , wherein determining whether the user is in contact with the steering wheel based on the determined phase shift includes determining that the user is in contact with the steering wheel when a maximum phase shift threshold is exceeded.

Assignees

• Ford Global Tech Llc

Inventors

• Trimboli Sergio
• Hause Ronny

Classifications

• B62D6/10 Primary

  characterised by means for sensing {or determining} torque · CPC title

• B60W40/09 Primary

  Driving style or behaviour · CPC title

• B60W2510/202

  Steering torque · CPC title

• B60W50/08 Primary

  Interaction between the driver and the control system · CPC title