Transmission with torque sensors and method of controlling a transmission

• US 20070199397A1
• Filed: 02/27/2006
• Published: 08/30/2007
• Est. Priority Date: 02/27/2006
• 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: Maten, John, Bockenstette, Casie
• Granted Patent: US 7,478,572 B2
• Time in Patent Office: Days
• US Class Current: 74/340
• CPC Class Codes: F16H 2200/0052 the gear ratios comprising six forward speeds
• CPC Class Codes: F16H 2306/00 Shifting
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 59/16 Dynamometric measurement of torque
• CPC Class Codes: F16H 61/688 with two inputs, e.g. selection of one of two torque-flow paths by clutches
• CPC Class Codes: Y10T 74/19233 Plurality of counter shafts
• CPC Class Codes: Y10T 74/19288 Double clutch and interposed transmission

Abstract

A transmission is provided with torque sensors on each of the power flow paths through the transmission so that actual torque data may be used in place of estimated data in controlling various vehicle operating characteristics, such as clutch apply or release, traction control, stability control and grade control, all of which are affected by the actual torque carried by the transmission. A method of controlling an automatic, multi-speed transmission includes operatively connecting the first torque sensor to the first shaft that partially establishes the first power flow path for a speed ratio of the transmission, sensing torque carried by the first shaft and controlling at least one vehicle operating characteristic based at least partially on the sensed torque.

Claims

1. A transmission comprising:

an input member;

an output member;

a first shaft at least partially defining a first power flow path between said input member and said output member;

a second shaft at least partially defining a second power flow path between said input member and said output member;

a first torque sensor operatively connected to said first shaft for sensing an amount of torque carried by said first shaft;

a second torque sensor operatively connected to said second shaft for sensing an amount of torque carried by said second shaft;

wherein said transmission is characterized by multiple speed ratios;

wherein at least one of said speed ratios is characterized by power flow along said first path; and

wherein at least another of said speed ratios is characterized by power flow along said second path.

2. The transmission of claim 1, further comprising:

a first torque-transmitting mechanism selectively engagable to at least partially establish power flow from said input member to said output member along said first power flow path; and

a second torque-transmitting mechanism selectively engagable to at least partially establish power flow from said input member to said output member along said second power flow path.

3. The transmission of claim 2, wherein disengagement of said first torque-transmitting mechanism and engagement of said second torque-transmitting mechanism at least partially accomplishes a shift from said one of said speed ratios to said another said speed ratios.

4. The transmission of claim 2, wherein alternate selective engagement of said first and said second torque-transmitting mechanism connects said input member with said first and second shafts, respectively.

5. The transmission of claim 2, wherein said first and second shafts are countershafts spaced generally parallel with said input member and said output member.

6. The transmission of claim 2, wherein said first and second shafts are coaxial.

7. The transmission of claim 2, wherein said torque sensors are magnetoelectric sensors.

8. The transmission of claim 1, further comprising:

a plurality of intermeshing gears, different ones of which at least partially form said power flow paths for transferring torque from said input member to said output member; and

wherein said torque sensors are operatively connected to said respective shafts upstream of at least some of said gears in said respective power flow paths.

9. The transmission of claim 1, further comprising:

a plurality of intermeshing gears, different ones of which at least partially form said respective power flow paths for transferring torque from said input member to said output member; and

wherein said torque sensors are operatively connected to said respective shafts downstream of at least some of said gears in said respective power flow paths

10. A transmission comprising:

an input member;

an output member;

a first shaft at least partially defining a first power flow path between said input member and said output member;

a second shaft at least partially defining a second power flow path between said input member and said output member;

a first torque sensor operatively connected to said first shaft for sensing an amount of torque carried by said first shaft;

a second torque sensor operatively connected to said second shaft for sensing an amount of torque carried by said second shaft;

a first torque-transmitting mechanism selectively engagable to at least partially establish power flow from said input member to said output member along said first power flow path;

a second torque-transmitting mechanism selectively engagable alternately with said first torque-transmitting mechanism to at least partially establish power flow from said input member to said output member along said second power flow path;

a plurality of intermeshing gears, different ones of which at least partially form said power flow paths for transferring torque from said input member to said output member; and

wherein said torque sensors are operatively connected to said respective shafts upstream of at least some of said gears in said respective power flow paths.

11. A method of controlling an automatic, multi-speed transmission, comprising:

operatively connecting a first torque sensor to a first shaft that partially establishes a first power flow path for a speed ratio of said transmission;

sensing torque carried by said first shaft via said first torque sensor; and

controlling at least one vehicle operating characteristic based at least partially on the sensed torque.

12. The method of claim 11, wherein said controlling step includes;

controlling engagement or disengagement of a first torque-transmitting mechanism that at least partially establishes the speed ratio.

13. The method of claim 12, wherein said controlling engagement includes:

updating an estimated control parameter used to establish a previous engagement or disengagement of the first torque-transmitting mechanism based on the sensed torque; and

utilizing the updated control parameter to establish a subsequent engagement or disengagement of the first torque-transmitting mechanism.

14. The method of claim 13, wherein the control parameter is time of full engagement of the first torque-transmitting mechanism.

15. The method of claim 12, further comprising:

operatively connecting a second torque sensor to a second shaft that partially establishes a second power flow path for a subsequent speed ratio of the transmission;

sensing torque carried by the second shaft via the second torque sensor; and

synchronizing engagement of the second torque-transmitting mechanism with disengagement of the first torque-transmitting mechanism based at least partially on the sensed torque carried by said second shaft.