TORQUE SENSOR PERFORMANCE DIAGNOSTIC SYSTEMS AND METHODS

• US 20100274443A1
• Filed: 08/26/2009
• Published: 10/28/2010
• Est. Priority Date: 04/22/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Dlugoss, Randall B.
• Granted Patent: US 8,417,411 B2
• Time in Patent Office: Days
• US Class Current: 701/34
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/16 Dynamometric measurement of torque
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: G01L 25/003 for measuring torque

Abstract

A control system may include a polarity determination module, a torque variation module, and a torque sensor diagnostic module. The polarity determination module determines a first polarity of a torque signal that indicates a transmission torque. The torque sensor diagnostic module diagnoses an error of a torque sensor when an detected polarity of the torque signal is opposite from the first polarity. A control system may include a torque variation module and a torque sensor diagnostic module. The torque variation module determines a maximum torque variation during a predetermined diagnostic period based on the torque signal. The torque sensor diagnostic module diagnoses an error of a torque sensor when the maximum torque variation is outside of a torque variation range. The torque variation range is defined by a minimum torque variation threshold and a maximum torque variation threshold.

Claims

1. A control system, comprising:

a polarity determination module that determines a first polarity of a torque signal of a torque sensor that indicates a transmission torque; and

a torque sensor diagnostic module that diagnoses an error of the torque sensor when a detected polarity of said torque signal is opposite from said first polarity.

2. The control system of claim 1, wherein said first polarity determination module determines said first polarity based on at least one of a transmission mode signal, a vehicle speed signal, and said torque signal.

3. The control system of claim 2, wherein said transmission mode signal indicates a mode of a transmission that operates in one of a park mode, a reverse mode, a neutral mode, a drive mode, and a gear mode.

4. The control system of claim 3, wherein said polarity determination module determines that said first polarity is a first polarity when said transmission is in said reverse mode, and

wherein said polarity determination module determines that said first polarity is a second polarity when said transmission is in one of said drive mode and said gear mode, where said second polarity is opposite said first polarity.

5. The control system of claim 3, wherein said polarity determination module refrains from determining said first polarity when said transmission is in one of said park mode and said neutral mode.

6. The control system of claim 2, wherein said polarity determination module refrains from determining said first polarity when said vehicle speed signal is less than a vehicle speed threshold.

7. The control system of claim 2, wherein said polarity determination module refrains from determining said first polarity when said torque signal is less than a transmission torque threshold.

8. The control system of claim 1, further comprising:

a polarity error timer that increments a time when said detected polarity is opposite from said first polarity; and

a polarity error counter that increments a cycle count when said time is greater than a predetermined period.

9. The control system of claim 8, wherein said torque sensor diagnostic module diagnoses said error of said torque sensor when said cycle count is greater than a cycle count threshold.

10. A control system, comprising:

a torque variation module that determines a maximum torque variation during a predetermined diagnostic period based on a torque signal that indicates a transmission torque; and

a torque sensor diagnostic module that diagnoses an error of a torque sensor when said maximum torque variation is outside of a torque variation range,

wherein said torque variation range is defined by a minimum torque variation threshold and a maximum torque variation threshold.

11. The control system of claim 10, wherein said torque variation module determines said maximum torque variation based on at least one of a transmission mode signal, a vehicle speed signal, and a brake signal.

12. The control system of claim 11, wherein said torque variation module refrains from determining said maximum torque variation when said transmission mode signal indicates that a transmission is shifting gears.

13. The control system of claim 11, wherein said torque variation module determines a vehicle acceleration value based on said vehicle speed signal, and

wherein said torque variation module refrains from determining said maximum torque variation when said vehicle acceleration value is greater than a vehicle acceleration threshold.

14. The control system of claim 11, wherein said torque variation module refrains from determining said maximum torque variation when said brake signal is greater than a brake level threshold.

15. The control system of claim 10, wherein said torque sensor diagnostic module increments a cycle count when said maximum torque variation is outside of said torque variation range for a predetermined error period.

16. The control system of claim 15, wherein said predetermined error period is based on a sampling period of said torque sensor.

17. The control system of claim 15, wherein said torque sensor diagnostic module diagnoses said error of said torque sensor when said cycle count is greater than a cycle count threshold.

18. The control system of claim 17, wherein said torque sensor diagnostic module decrements said cycle count when said maximum torque variation is within said torque variation range for a predetermined non-error period and said cycle count is greater than zero.

19. The control system of claim 18, wherein said predetermined non-error period is based on a measured period from a first time when a first error of said torque sensor is diagnosed to a second time when a second error of said torque sensor is diagnosed.

20. The control system of claim 17, wherein said torque sensor diagnostic module activates a service indicator when said error of said torque sensor is diagnosed, and

wherein said torque sensor diagnostic module deactivates said service indicator when said maximum torque variation is within said torque variation range for N ignition cycles, where N is an integer greater than one.