Systems and methods for detecting steering wheel contact
Disclosed herein are systems and methods that describe systems and method for detecting operator contact with a steering wheel of a vehicle. The system can include: a steering wheel, a drive motor coupled to the steering wheel, and a drive motor controller that controls the operation of the drive motor. The drive motor controller can detect contact between the operator and the steering wheel. In one aspect, the systems and methods can be used to alert the operator of the vehicle when operator contact with the steering wheel is not detected.
1. A system for detecting operator contact with a steering wheel of a vehicle, the system comprising:
a steering wheel;
a drive motor coupled to the steering wheel; and
a drive motor controller that controls the operation of the drive motor;
wherein the drive motor controller:
generates and communicates a drive signal to the drive motor to apply a force to the steering wheel,
measures a current generated from a back electromotive force (back-EMF) on the drive motor resulting from the operator's reactions to the force applied by the drive motor,
compares the current with a predefined current range, and
in response to the current being greater than the predefined current range, determines contact between the operator and the steering wheel, and
in response to the current being less than or within the predefined current range, determines a lack of contact between the operator and the steering wheel.
2. The system of claim 1 , wherein the steering wheel comprises a steering wheel base, and the drive motor is disposed adjacent the steering wheel base.
3. The system of claim 1 , wherein the drive motor is operationally connected to one or more gears that rotate the steering wheel.
4. The system of claim 1 , wherein the drive motor controller controls the operation of the drive motor by regulating power to the drive motor.
5. The system of claim 1 , wherein the drive motor controller applies the force to the steering wheel through the drive motor and, after measuring the current generated on the drive motor by the back EMF, associates the back-EMF on the drive motor with a respective current value.
6. The system of claim 5 , wherein the current range is between 1 amp and 4 amps and wherein the drive motor controller measures the current generated on the drive motor after applying the force to the steering wheel.
7. The system of claim 1 , wherein the measuring is performed periodically.
8. The system of claim 7 , wherein periodically is one one-hundredths of a millisecond.
9. The system of claim 1 wherein the drive motor is a component of an active steering system.
10. The system of claim 9 , wherein the drive motor controller is a component of the active steering system.
11. The system of claim 1 , wherein applying a force comprises applying at least one pulse of electric current.
12. The system of claim 1 , wherein the drive motor controller communicates the determination to an autonomous driving system, cruise control system, and/or a safety system.
13. The system of claim 12 , wherein at least one action is taken as a result of the determination.
14. The system of claim 13 , wherein the at least one action comprises sending an alert to the operator of the vehicle.
15. The system of claim 14 , wherein the alert comprises a visual signal that is displayed to the operator.
16. The system of claim 14 , wherein the alert comprises an audio signal that is broadcast to the operator.
17. The system of claim 14 , wherein the alert comprises a vibrational signal that is mechanically imparted and receivable by the operator's body.
18. The system of claim 1 , wherein if the velocity of the vehicle is greater than a predefined velocity threshold value, the drive motor controller applies a first force to the steering wheel, and if the velocity of the vehicle is less than the predefined velocity threshold value, the drive motor controller applies a second force to the steering wheel, wherein the first force is less than the second force.
19. The system of claim 1 , wherein if the steering wheel is rotating with an angular velocity greater than a predefined angular velocity threshold value, the drive motor controller applies a first force to the steering wheel, and if the angular velocity is less than the predefined angular velocity threshold value, the drive motor controller applies a second force to the steering wheel, wherein the first force is greater than the second force.
20. The system of claim 1 , wherein the drive motor is disposed adjacent to a clock spring housing of the steering wheel.
21. The system of claim 1 , wherein the drive motor controller receives a velocity and/or an acceleration of the vehicle and/or an angular velocity of the steering wheel, adjusts the measured current based on the receive velocity, acceleration, and/or angular velocity, and compares the adjusted current with the predefined current range.
22. A method for detecting operator contact with a steering wheel of a vehicle, the method comprising:
generating and communicating a drive signal, by a drive motor controller, to a drive motor to apply a force to a steering wheel, wherein the drive motor is coupled to the steering wheel, and the drive motor controller controls the operation of the drive motor,
measuring a current generated from a back electromotive force (back-EMF) on the drive motor resulting from the operator's reactions to the force applied by the drive motor,
comparing, by the drive motor controller, the current with a predefined current range,
in response to the current being greater than the predefined range, determining contact between the operator and the steering wheel, and
in response to the current being less than or within the predefined range, determining a lack of contact between the operator and the steering wheel.
23. The method of claim 22 , wherein the steering wheel comprises a steering wheel base, and the drive motor is disposed adjacent the steering wheel base.
24. The method of claim 22 , wherein the drive motor is operationally connected to one or more gears that rotate the steering wheel.
25. The method of claim 22 , wherein the drive motor controller controls the operation of the drive motor by regulating power to the drive motor.
26. The method of claim 22 , wherein the drive motor controller receives the back-EMF on the drive motor and associates the back-EMF on the drive motor with a current value.
27. The method of claim 26 , wherein the current range is between 1 amp and 4 amps and wherein the drive motor controller measures the current generated on the drive motor after applying the force to the steering wheel.
28. The method of claim 22 , wherein the measuring is performed periodically.
29. The method of claim 28 , wherein periodically is one one-hundredths of a millisecond.
30. The method of claim 22 , wherein the drive motor is a component of an active steering system.
31. The method of claim 29 , wherein the drive motor controller is a component of the active steering system.
32. The method of claim 22 , wherein applying a force comprises applying a pulse of electric current.
33. The method of claim 22 , further comprising communicating the determination to an autonomous driving system, cruise control system, and/or a safety system.
34. The method of claim 33 , wherein at least one action is taken as a result of the determination.
35. The method of claim 34 , wherein the at least one action comprises sending an alert to the operator of the vehicle.
36. The method of claim 35 , wherein the alert comprises a visual signal that is displayed to the operator.
37. The method of claim 35 , wherein the alert comprises an audio signal that is broadcast to the operator.
38. The method of claim 35 , wherein the alert comprises a vibrational signal that is mechanically imparted and receivable by the operator's body.
39. The method of claim 22 , wherein if the velocity of the vehicle is greater than a predefined velocity threshold value, the drive motor controller applies a first force to the steering wheel, and if the velocity of the vehicle is less than the predefined velocity threshold value, the drive motor controller applies a second force to the steering wheel, wherein the first force is less than the second force.
40. The method of claim 22 , wherein if the steering wheel is rotating with an angular velocity greater than a predefined angular velocity threshold value, the drive motor controller applies a first force to the steering wheel, and if the angular velocity is less than the predefined angular velocity threshold value, the drive motor controller applies a second force to the steering wheel, wherein the first force is greater than the second force.
41. The method of claim 22 , wherein the drive motor is disposed adjacent to a clock spring housing of the steering wheel.