Steering angle sensor assembly with pulse width modulated output signal

• US 7,236,907 B2
• Filed: 12/22/2004
• Issued: 06/26/2007
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH), Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Knoll, Stefan, Stuckey, Eric, Rohrkemper, Darin, Kaster, Robert
• Primary Examiner(s): Wachsman; Hal
• Assistant Examiner(s): Desta; Elias
• Application Number:
  US11/023,898
• Publication Number:
  US 20060136171A1
• Time in Patent Office: 916 Days
• Field of Search: 702/150, 702/151, 702/189, 702/190, 700/303, 340/465, 701/36, 701/41
• US Class Current: 702/151
• CPC Class Codes: B62D 15/0215 by measuring on the steering column
• CPC Class Codes: G01D 5/3473 Circular or rotary encoders
• CPC Class Codes: G01D 5/366 Particular pulse shapes

Abstract

A steering angle sensing system includes at least one steering angle sensing device for outputting an analog signal representative of a steering angle position of a steering wheel. A first processor is operably coupled to the at least one steering angle sensing device and is disposed proximate the at least one steering angle sensing device. The first processor receives the analog signals output by the at least one steering angle sensing device, computes a steering angle value based upon the analog signals, and outputs a pulse width modulated signal representative of the computed steering angle value. A second processor is disposed non-proximate the at least one steering angle sensing device and is operably coupled to the first processor to thereby receive the pulse width modulated signal representative of the computed steering angle value.

Claims

1. A steering angle sensing system comprising:

at least one steering angle sensing device configured to output an analog signal representative of a steering angle position of a steering wheel;

a first processor operably coupled to said at least one steering angle sensing device, said first processor being configured to;

receive the analog signals output by said at least one steering angle sensing device;

compute a steering angle value based upon the analog signals; and

output a pulse width modulated signal representative of the computed steering angle value; and

a second processor operably coupled to said first processor to thereby receive the pulse width modulated signal representative of the computed steering angle value.

2. The steering angle sensor system of claim 1 wherein said second processor is configured to output a control signal to control operation of at least one component of a vehicle steered via the steering wheel.

3. The steering angle sensor system of claim 2 wherein said second processor is configured to be operably coupled to at least one other vehicle sensing device to thereby receive another signal from the other vehicle sensing device.

4. The steering angle sensor system of claim 1 further comprising a single conductor configured to carry an entirety of the pulse width modulated signal from said first processor to said second processor.

5. The steering angle sensor system of claim 4 wherein said second processor is configured to sense an absence of the pulse width modulated signal on the single conductor.

6. The steering angle sensor system of claim 1 wherein said first processor is disposed proximate said at least one steering angle sensing device and said second processor is disposed at a location remote from said at least one steering angle sensing device.

7. The steering angle sensor system of claim 1 wherein a duty cycle of the pulse width modulated signal is indicative of the computed steering angle value.

8. The steering angle sensor system of claim 7 wherein the duty cycle of the pulse width modulated signal varies linearly with the computed steering angle value.

9. A steering angle sensor assembly comprising:

at least one steering angle sensing device configured to output a first signal dependent upon a steering angle position; and

a first processor operably coupled said at least one steering angle sensing device, said first processor being configured to;

receive the signals output by said at least one steering angle sensing device;

determine a steering angle value based upon the analog signals; and

transmit a second signal to a second processor over a single conductor, wherein the second signal is representative of the determined steering angle value.

10. The steering angle sensor assembly of claim 9 wherein said first processor is disposed proximate said at least one steering angle sensing device and said second processor is disposed remotely from said at least one steering angle sensing device.

11. The steering angle sensor assembly of claim 9 wherein the second signal comprises a pulse width modulated signal.

12. The steering angle sensor assembly of claim 11 wherein a duty cycle of the pulse width modulated signal is indicative of the determined steering angle value.

13. The steering angle sensor assembly of claim 12 wherein the duty cycle of the pulse width modulated signal varies linearly with the determined steering angle value.

14. A method of sensing a steering angle, comprising the steps of:

operably coupling a first processor to at least one steering angle sensing device;

transmitting at least one analog signal from said at least one steering angle sensing device to said first processor, the at least one analog signal being representative of a steering angle position of a steering wheel;

determining a steering angle value based upon the analog signals;

operably coupling a second processor to said first processor; and

transmitting a pulse width modulated signal from said first processor to said second processor, the pulse width modulated signal being representative of the determined steering angle value.

15. The method of claim 14 comprising the further step of outputting a control signal from said second processor to control operation of at least one component of a vehicle steered via the steering wheel.

16. The method of claim 15 comprising the further steps of:

operably coupling said second processor to at least one other vehicle sensing device; and

transmitting another signal from the other vehicle sensing device to said second processor.

17. The method of claim 14 comprising the further step of carrying an entirety of the pulse width modulated signal on a single conductor from said first processor to said second processor.

18. The method of claim 17 comprising the further step of using said second processor to sense an absence of the pulse width modulated signal on the single conductor.

19. The method of claim 14 wherein said first processor is disposed proximate said at least one steering angle sensing device and said second processor is disposed at a location remote from said at least one steering angle sensing device.

20. The method of claim 14 wherein a duty cycle of the pulse width modulated signal is indicative of the computed steering angle value.

21. The method of claim 20 wherein the duty cycle of the pulse width modulated signal varies linearly with the computed steering angle value.