System and method for using actuator coil inductance to diagnose stuck differential

Patent metadata

Field	Value
Publication number	US-10352729-B2
Application number	US-201715421988-A
Country	US
Kind code	B2
Filing date	Feb 1, 2017
Priority date	Feb 1, 2017
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A system is disclosed for detecting when an electronic locking (e-Locker) differential of a vehicle is in a stuck condition. The system may have an e-Locker differential for driving a plurality of wheels, and may be configured to move between first and second positions, one of which places the e-Locker differential in a locked state, and the other of which places it in an unlocked state. An e-Locker coil, when energized may cause movement of the differential e-Locker actuator between the first and second positions. A position sensing subsystem may use an inductance of the e-Locker coil to determine if the differential e-Locker actuator is stuck in one of the first and second positions.

First claim

What is claimed is:

1. A system for detecting when an electronic locking (e-Locker) differential of a vehicle is in a stuck condition, comprising:
an e-Locker differential configured to drive a plurality of wheels of the vehicle;
a differential e-Locker actuator configured to move between first and second positions, wherein one of the first and second positions places the e-Locker differential in a locked state, and the other of the first and second positions places the e-Locker differential in an unlocked state;
an e-Locker coil operably associated with the differential e-Locker actuator configured to move the differential e-Locker actuator between the first and second positions depending on whether the e-Locker coil is energized,
wherein the e-Locker coil has a first inductance when the differential e-Locker actuator is in the first position and has a second inductance when the differential e-Locker actuator is in the second position,
wherein the first inductance is greater than the second inductance;
an inductance measuring circuit for measuring the inductance of the e-Locker coil; and
a diagnostic subsystem configured to, based on the measured inductance of the e-Locker coil, determine if the differential e-Locker actuator is stuck in a position that is not the same as a commanded position, and to generate an output signal that indicates whether the differential e-Locker actuator is stuck in a position that is not the same as the commanded position.

2. The system of claim 1 , further comprising a differential e-Locker actuator controller configured to command the differential e-Locker actuator to move between the first and second positions.

3. The system of claim 2 , wherein the differential e-Locker actuator controller is in communication with the diagnostic subsystem.

4. The system of claim 3 , further comprising a controller in communication with the differential e-Locker actuator controller.

5. The system of claim 1 , further comprising an e-Locker controller configured to command the differential e-Locker actuator to move between the first and second positions.

6. The system of claim 1 wherein the diagnostic subsystem is configured to:
determine an expected inductance of the e-Locker coil based on the commanded position; and
determine if the e-Locker actuator is stuck in a position that is not the same as the commanded position based on a comparison of the measured inductance of the e-Locker coil and the expected inductance of the e-Locker coil.

7. A system for detecting when an electronic locking (e-Locker) differential of a vehicle is in a stuck condition, comprising:
an e-Locker differential configured to drive a plurality of wheels of the vehicle;
a differential e-Locker actuator configured to move between first and second positions, wherein the e-Locker differential is in a locked state when the differential e-Locker actuator is in the first position, and the e-Locker differential is in an unlocked state when the differential e-Locker actuator is in the second position;
an e-Locker coil operably associated with the differential e-Locker actuator and configured to move the differential e-Locker actuator between the first and second positions depending on whether the e-Locker coil is energized,
wherein the e-Locker coil has a first inductance with the differential e-Locker actuator is in the first position and has a second inductance when the differential e-Locker actuator is in the second position;
a sensor configured to sense one of (a) a position of the differential e-locker actuator and (b) an inductance of the e-Locker coil;
a diagnostic subsystem configured to, based on input from the sensor, determine if the differential e-Locker actuator is stuck in a position that is not the same as a commanded position, and to generate an output signal that indicates whether the differential e-Locker actuator is stuck in a position that is not the same as the commanded position;
an e-Locker actuator controller configured to command the differential e-Locker actuator to move between the first and second positions in response to e-Locker engage and disengage commands; and
a controller in communication with the e-Locker actuator controller and configured to generate the e-Locker engage and disengage commands.

8. The system of claim 7 wherein the controller is configured to generate the e-locker engage and disengage commands based on signals from a driver e-Lock input selector.

9. The system of claim 7 wherein the differential e-Locker actuator comprises a solenoid valve that actuates between the first and second positions.

10. The system of claim 9 wherein the differential e-Locker actuator further comprises a spring that urges the solenoid valve to the second position when the e-Locker coil is not energized.

11. The system of claim 7 wherein the e-Locker differential is configured to drive rotation of the plurality of wheels at the same rotational speed when the e-locker differential is in the locked state.

12. The system of claim 7 wherein the e-Locker differential is configured to allow rotation of the plurality of wheels at different rotational speeds when the e-locker differential is in the unlocked state.

13. A system for detecting when an electronic locking (e-Locker) differential of a vehicle is in a stuck condition, comprising:
an e-Locker differential configured to drive a plurality of wheels of the vehicle;
a differential e-Locker actuator configured to move between first and second positions, wherein the e-Locker differential is in a locked state when the differential e-Locker actuator is in the first position, and the e-Locker differential is in an unlocked state when the differential e-Locker actuator is in the second position;
an e-Locker coil operably associated with the differential e-Locker actuator and configured to move the differential e-Locker actuator between the first and second positions depending on whether the e-Locker coil is energized,
wherein the e-Locker coil has a first inductance with the differential e-Locker actuator is in the first position and has a second inductance when the differential e-Locker actuator is in the second position,
wherein the first inductance is greater than the second inductance;
a sensor configured to sense one of (a) a position of the differential e-locker actuator and (b) an inductance of the e-Locker coil;
a diagnostic subsystem configured to, based on input from the sensor, determine if the differential e-Locker actuator is stuck in a position that is not the same as a commanded position, and to generate an output signal that indicates whether the differential e-Locker actuator is stuck in a position that is not the same as the commanded position; and
an e-Locker actuator controller configured to command the differential e-Locker actuator to move between the first and second positions in response to e-Locker engage and disengage commands.

14. A system for detecting when an electronic locking (e-Locker) differential of a vehicle is in a stuck condition, comprising:
an e-Locker differential configured to drive a plurality of wheels of the vehicle;
a differential e-Locker actuator configured to move between first and second positions, wherein the e-Locker differential is in a locked state when the differential e-Locker actuator is in the first position, and the e-Locker differential is in an unlocked state when the differential e-Locker actuator is in the second position;
an e-Locker coil operably associated with the differential e-Locker actuator and configured to move the differential e-Locker actuator between the first and second positions dep

Assignees

• Gm Global Tech Operations Llc

Inventors

• Suntharalingam Piranavan

Classifications

• F16H48/34

  using electromagnetic or electric actuators · CPC title

• F16H2048/346

  using a linear motor · CPC title

• F16H48/20 Primary

  Arrangements for suppressing or influencing the differential action, e.g. locking devices · CPC title

• F16H2048/204

  Control of arrangements for suppressing differential actions · CPC title

• G01D5/20 Primary

  by varying inductance, e.g. by a movable armature · CPC title