METHOD AND APPARATUS FOR FAULT-TOLERANT TRANSMISSION GEAR SELECTOR LEVER POSITION DETERMINATION

• US 20080028879A1
• Filed: 08/04/2006
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company), Electronic Data Systems Corporation (Perspecta, Inc.)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Wu, Peter E., Robinette, Richard E.
• Granted Patent: US 7,568,402 B2
• Time in Patent Office: Days
• US Class Current: 74/335
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/1232 Bringing the control into a predefined state, e.g. giving priority to particular actuators or gear ratios
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/105 consisting of electrical switches or sensors
• 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: Y10S 477/906 Means detecting or ameliorating the effects of malfunction or potential malfunction
• CPC Class Codes: Y10T 74/19251 Control mechanism

Abstract

A fault-tolerant gear selector lever position apparatus is described. Included is a first sensor operable to detect each position, and a second sensor operable to detect subsets of the positions. A first controller monitors the second sensor, and a second controller monitors the first sensor. The second controller identifies and communicates one of the positions to the first controller, and the first controller validates the position and communicates the position to a control system. The lever is applicable to a power transmission device. Each sensor preferably comprises digital encoding sensor; the first sensor generates a unique signal for each position, and the second sensor generates a unique signal for each subset of the positions, preferably a unique signal for each of Park, Reverse, Neutral, and Forward Drive. The controllers identify faults in the sensors, and communicate and act accordingly.

Claims

1. Apparatus to determine a position of a lever having a plurality of operator-selectable positions, comprising:

a first lever-position sensor operable to detect each of the operator-selectable positions;

a second lever-position sensor operable to detect each of a subset of the operator-selectable positions;

a first controller adapted to monitor the second lever-position sensor;

a second controller adapted to monitor the first lever-position sensor;

the second controller operable to identify and communicate a specific one of the operator-selectable positions to the first controller;

the first controller operable to validate the specific one of the operator-selectable positions and communicate the validated specific one of the operator-selectable positions to a control system.

2. The apparatus of claim 1, wherein the lever having a plurality of operator-selectable positions comprises a gear selector lever for a power transmission device.

3. The apparatus of claim 2, wherein the first lever-position sensor comprises a sensor operable to generate a unique signal for each of the operator-selectable positions.

4. The apparatus of claim 3, wherein the first lever-position sensor further comprises a first digital encoding sensor operable to generate the unique signal for each of the operator-selectable positions.

5. The apparatus of claim 2, wherein the second lever-position sensor comprises a sensor operable to generate a unique signal for each subset of operator-selectable positions, wherein each subset is determined based upon an operator-selected direction of rotation of an output of the power transmission device.

6. The apparatus of claim 5, wherein the second lever-position sensor further comprises a second digital encoding sensor operable to generate the unique signal for each subset of operator-selectable position.

7. The apparatus of claim 6, wherein each subset determined based upon the operator-selected direction of rotation of the power transmission device further comprises the digital encoding sensor operable to generate a unique signal for each of Park, Reverse, Neutral, and Forward Drive.

8. The apparatus of claim 1, comprising the first controller adapted to identify a fault in the second lever-position sensor.

9. The apparatus of claim 2, comprising the first controller adapted to communicate the fault in the second lever-position sensor to the second controller.

10. The apparatus of claim 9, comprising the second controller adapted to identify a fault in the first lever-position sensor.

11. The apparatus of claim 10, comprising the second controller adapted to identify a fault in the first controller.

12. The apparatus of claim 11, comprising the second controller adapted to communicate a default lever position to the control system when a fault is identified in one of the first and second lever-position sensors and the first controller.

13. The apparatus of claim 12, further comprising the control system operable to generate a diagnostic fault code when the fault identified in one of the first and second lever-position sensors and the first controller is communicated thereto.

14. The apparatus of claim 13, wherein the lever having a plurality of operator-selectable positions comprises a gear selector lever for a power transmission device.

15. The apparatus of claim 14, further comprising:

the first lever-position sensor operable to generate a unique signal for each of the operator-selectable positions, and,

the second lever-position sensor operable to generate a unique signal for each of a subset of operator-selectable positions, each subset determined based upon a direction of rotation of an output of the power transmission device.

16. The apparatus of claim 1, wherein the first controller operable to validate the specific one of the operator-selectable positions further comprises the first controller operable to validate the specific one of the operator-selectable positions based upon the monitored input from the second lever-position sensor.

17. Method for determining a position of a gear selector lever having a plurality of operator-selectable positions, comprising:

detecting one of a plurality of operator-selectable positions of the gear selector lever;

detecting one of a plurality of subsets of the operator-selectable positions;

validating the specific one of the operator-selectable positions based upon the detected one of the subset of operator-selectable positions; and

,

communicating the validated specific one of the operator-selectable positions to a control system.

18. The method of claim 17, wherein detecting one of a plurality of operator-selectable positions of the gear selector lever further comprises detecting selectable positions for a gear selector lever for a power transmission device.

19. The method of claim 18, wherein detecting one of a plurality of operator-selectable positions of the gear selector lever further comprises generating a unique signal for each of the operator-selectable positions.

20. The method of claim 19, wherein detecting a one of a subset of the operator-selectable positions further comprises generating a unique signal for each of Park, Reverse, Neutral, and Forward Drive.

21. The method of claim 17, wherein validating the specific one of the operator-selectable positions based upon the detected one of the plurality of the subset of the operator-selectable positions further comprises identifying a fault.

22. The method of claim 21, comprising communicating a default gear selector lever position when a fault is identified.

23. The method of claim 22, further comprising generating a diagnostic fault code when the fault identified.

24. Apparatus for determining position of a transmission gear selector lever in a vehicle having a propulsion system equipped with an automatic transmission utilizing shift-by-wire shifting architecture and a distributed electronic controller architecture, comprising:

a range encoder, operable to provide a signal output for each valid transmission gear selector lever position;

a direction encoder, operable to provide signal outputs corresponding to the Park, Reverse, Neutral, and Forward positions of the transmission gear selector lever, and, mechanically aligned with the range encoder;

a first control module;

adapted to read and decode the signal output from the direction encoder;

adapted to identify faults of the direction encoder;

adapted to validate a transmission gear selector lever position communicated from a second control module; and

,

adapted to provide a control signal to the propulsion system comprising the validated transmission gear selector lever position; and

,

the second control module;

adapted to read and decode the signal output from the range encoder to determine transmission gear selector lever position;

adapted to identify faults of the range encoder;

adapted to communicate the transmission gear selector lever position to the first control module; and

,

adapted to provide a control signal to the propulsion system comprising a limp-home mode when a fault is identified in one of the direction encoder, the range encoder, and the first control module.