Method for dynamically determining peak output torque in an electrically variable transmission

• US 20050252305A1
• Filed: 04/22/2005
• Published: 11/17/2005
• Est. Priority Date: 05/15/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Hubbard, Gregory A., Hsieh, Tung-Ming
• Granted Patent: US 7,305,873 B2
• Time in Patent Office: Days
• US Class Current: 73/860
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/184 Preventing damage resulting from overload or excessive wear of the driveline
• CPC Class Codes: F16H 2037/0866 Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: F16H 2037/102 the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2200/201 with three sets of orbital gears
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A method for determining output torque limits of a powertrain including an electrically variable transmission relies upon a model of the electrically variable transmission. Transmission operating space is defined by combined electric machine torque constraints and engine torque constraints. Output torque limits are determined at the limits of the transmission operating space.

Claims

1. Method for determining output torque limits in a vehicular powertrain comprising an engine, an electrically variable transmission including at least one electric motor, and a driveline, said engine operatively coupled to the electrically variable transmission at an input thereof, said driveline operatively coupled to the electrically variable transmission at an output thereof, comprising:

determining a feasible motor torque operating space;

determining input torque limits within the feasible motor torque operating space;

determining motor torque limits at the input torque limits; and

determining output torque limits based upon the input torque limits and the motor torque limits.

2. The method for determining output torque limits as claimed in claim 1 wherein the feasible motor torque operating space is determined to provide torque capacity reservation in said at least one electric motor.

3. The method for determining output torque limits as claimed in claim 1 wherein said input torque limits are determined based upon engine torque limits and motor torque limits of the feasible motor torque operating space.

4. The method for determining output torque limits as claimed in claim 1 wherein determined motor torque limits at the input torque limits correspond to the least constrained output torques.

5. Method for determining output torque limits in a vehicular powertrain comprising an engine, an electrically variable transmission including at least one electric motor, and a driveline, said engine operatively coupled to the electrically variable transmission at an input thereof, said driveline operatively coupled to the electrically variable transmission at an output thereof, comprising:

determining input torque limits as the most constrained of input torques corresponding to predetermined engine torque limits and predetermined motor torque limits;

determining which of the predetermined motor torque limits correspond to the least constrained output torques at the input torque limits; and

determining the output torque limits based upon the input torque limits and the predetermined motor torque limits that correspond to the least constrained output torques at the input torque limits.

6. The method for determining output torque limits as claimed in claim 5 wherein the engine torque limits are determined in accordance with a set of engine operating parameters.

7. The method for determining output torque limits as claimed in claim 6 wherein the engine torque limits are determined from stored data sets in a controller.

8. The method for determining output torque limits as claimed in claim 6 wherein the engine torque limits are determined in real-time in a controller.

9. The method for determining output torque limits as claimed in claim 5 wherein the motor torque limits are determined in accordance with a set of motor operating parameters.

10. The method for determining output torque limits as claimed in claim 9 wherein the motor torque limits are determined from stored data sets in a controller.

11. The method for determining output torque limits as claimed in claim 5 wherein the motor torque limits are determined to provide a reservation of torque capacity in said at least one electric motor.

12. Method for determining output torque limits in a vehicular powertrain comprising an engine, an electrically variable transmission including at least one electric motor, and a driveline, said engine operatively coupled to the electrically variable transmission at an input thereof, said driveline operatively coupled to the electrically variable transmission at an output thereof, comprising:

determining least constrained motor limited input torques corresponding to predetermined motor torque limits;

determining engine limited input torques corresponding to predetermined engine torque limits;

selecting input torque limits as the most constrained of the motor limited input torques and the engine limited input torques; and

determining output torque limits as the least constrained of output torques corresponding to said input torque limits and said predetermined motor torque limits.

13. The method for determining output torque limits as claimed in claim 12 wherein the engine torque limits are determined in accordance with a set of engine operating parameters.

14. The method for determining output torque limits as claimed in claim 13 wherein the engine torque limits are determined from stored data sets in a controller.

15. The method for determining output torque limits as claimed in claim 13 wherein the engine torque limits are determined in real-time in a controller.

16. The method for determining output torque limits as claimed in claim 12 wherein the motor torque limits are determined in accordance with a set of motor operating parameters.

17. The method for determining output torque limits as claimed in claim 16 wherein the motor torque limits are determined from stored data sets in a controller.

18. The method for determining output torque limits as claimed in claim 12 wherein the motor torque limits are determined to provide a reservation of torque capacity in said at least one electric motor.