METHOD AND APPARATUS TO DETERMINE A PREFERRED OUTPUT TORQUE FOR OPERATING A HYBRID TRANSMISSION IN A FIXED GEAR OPERATING RANGE STATE

• US 20090118944A1
• Filed: 10/21/2008
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), FCA US LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), Daimler AG (Mercedes-Benz Group AG), GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Wu, Bin, Hsieh, Tung-Ming
• Granted Patent: US 8,135,519 B2
• Time in Patent Office: Days
• US Class Current: 701/54
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 10/115 with planetary gears
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2510/105 Output torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/105 : Output torque
• 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 2037/106 : with switching means to provide two variator modes or ranges
• 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

Abstract

A hybrid transmission includes a torque machine and an energy storage device connected thereto. The hybrid transmission is operative to transfer power between an input member and an output member and the torque machines in a fixed gear operating range state. A method for controlling the hybrid transmission includes determining a preferred output torque, determining a relationship between power from the energy storage device and an output torque of the transmission, determining power constraints from the energy storage device, determining motor torque constraints for the torque machine, determining linear torque constraints to the output torque based upon the motor torque constraints for the torque machine, determining quadratic output torque constraints based upon the power constraints from the energy storage device and the relationship between the power from the energy storage device and the output torque of the transmission device, and determining an output torque to the output member responsive to the preferred output torque and achievable based upon the linear output torque constraints and the quadratic output torque constraints.

Claims

1. Method for controlling a hybrid transmission including a torque machine and an energy storage device connected thereto, the hybrid transmission operative to transfer power between an input member and an output member and the torque machines in a fixed gear operating range state, the method comprising:

determining a preferred output torque;

determining a relationship between power from the energy storage device and an output torque of the transmission;

determining power constraints from the energy storage device;

determining motor torque constraints for the torque machine;

determining linear torque constraints to the output torque based upon the motor torque constraints for the torque machine;

determining quadratic output torque constraints based upon the power constraints from the energy storage device and the relationship between the power from the energy storage device and the output torque of the transmission device; and

determining an output torque to the output member responsive to the preferred output torque and achievable based upon the linear output torque constraints and the quadratic output torque constraints.

2. The method of claim 1, comprising determining the preferred output torque based upon an operator torque request.

3. The method of claim 1, further comprising:

determining the preferred output torque based upon an operator torque request via a brake pedal; and

determining an output torque range to the output member responsive to the preferred output torque and achievable based upon the linear output torque constraints and the quadratic output torque constraints.

4. The method of claim 3, comprising determining a capacity for regenerative braking based upon the output torque range to the output member that is responsive to the preferred output torque and achievable based upon the linear output torque constraints and the quadratic output torque constraints.

5. The method of claim 4, further comprising determining an output torque to the output member that is responsive to the preferred output torque and maximizes power flow from the torque machine to the energy storage device and is achievable based upon the linear output torque constraints and the quadratic output torque constraints.

6. The method of claim 1, further comprising determining an output torque to the output member responsive to the preferred output torque that is achievable based upon the linear output torque constraints and the quadratic output torque constraints and minimizes power flow from the energy storage device to the torque machine.

7. The method of claim 1, comprising:

determining clutch torque constraints for the applied torque transfer clutches for the fixed gear operating range state; and

determining maximum and minimum linear output torque constraints based upon the clutch torque constraints and the motor torque constraints for the torque machines.

8. Method for controlling an electromechanical transmission including first and second electric machines and an electrical energy storage device connected thereto, the electromechanical transmission operative to transfer power between an input member and an output member and the first and second electric machines in a fixed gear operating range state, the method comprising:

determining a preferred output torque;

determining a relationship between power from the electrical energy storage device and an output torque transmitted to the output member;

determining power constraints from the electrical energy storage device;

determining motor torque constraints for the first and second electric machines;

determining a first output torque constraint based upon the motor torque constraints for the first and second electric machines;

determining a second output torque constraint based upon the power constraints from the electrical energy storage device and the relationship between the power from the electrical energy storage device and the output torque; and

determining an output torque responsive to the preferred operator torque request and achievable based upon the first and second output torque constraints.

9. The method of claim 8, comprising determining the preferred output torque based upon an operator torque request.

10. The method of claim 8, further comprising:

determining the preferred output torque based upon an operator torque request via a brake pedal; and

determining an output torque range to the output member responsive to the preferred output torque and achievable based upon the first and second output torque constraints.

11. The method of claim 10, comprising determining a capacity for regenerative braking based upon the output torque range to the output member that is responsive to the preferred output torque and achievable based upon the first and second output torque constraints.

12. The method of claim 10, further comprising determining an output torque to the output member that is responsive to the preferred output torque and maximizes power flow from the torque machine to the energy storage device and is achievable based upon the first and second output torque constraints.

13. The method of claim 12, further comprising determining an output torque to the output member responsive to the preferred output torque that is achievable based upon the first and second output torque constraints and minimizes power flow from the energy storage device to the torque machine.

14. Method for controlling a hybrid transmission including electric machines and an energy storage device connected thereto, the electromechanical transmission operative in a fixed gear operating range state to transfer power between an input member and an output member and the electric machines, the method comprising:

determining a preferred output torque;

determining a relationship between power from the energy storage device and an output torque of the transmission;

determining power constraints from the energy storage device;

determining motor torque constraints for the electric machines;

determining maximum and minimum linear output torque constraints based upon the motor torque constraints for the electric machines;

determining maximum and minimum quadratic output torque constraints based upon the power constraints from the energy storage device and the relationship between the power from the energy storage device and the output torque of the transmission device; and

determining an output torque responsive to the preferred operator torque request and achievable based upon the linear torque constraints and the quadratic output torque constraint.

15. The method of claim 14, further comprising:

determining the preferred output torque based upon an operator torque request via a brake pedal; and

determining an output torque range to the output member responsive to the preferred output torque and achievable based upon the maximum and minimum linear output torque constraints and the maximum and minimum quadratic output torque constraints.

16. The method of claim 15, comprising determining a capacity for regenerative braking based upon the output torque range to the output member that is responsive to the preferred output torque and achievable within the maximum and minimum linear output torque constraints and the maximum and minimum quadratic output torque constraints.

17. The method of claim 16, further comprising determining an output torque to the output member that is responsive to the preferred output torque and maximizes power flow from the torque machine to the energy storage device and is achievable within the maximum and minimum linear output torque constraints and the maximum and minimum quadratic output torque constraints.

18. The method of claim 14, wherein the output torque responsive to the preferred operator torque request and achievable based upon the linear torque constraints and the quadratic output torque constraint comprises the maximum linear output torque constraint when the maximum linear output torque constraint is less than the maximum quadratic output torque constraint and the powertrain is operating to generate tractive torque during a non-regenerative operation.

19. The method of claim 14, wherein the output torque responsive to the preferred operator torque request and achievable based upon the linear torque constraints and the quadratic output torque constraint comprises the maximum quadratic output torque constraint when the maximum linear output torque constraint is greater than the maximum quadratic output torque constraint and the powertrain is operating to generate tractive torque during a non-regenerative operation.

20. The method of claim 14, wherein the output torque responsive to the preferred operator torque request and achievable based upon the linear torque constraints and the quadratic output torque constraint comprises the minimum linear output torque constraint when the minimum linear output torque constraint is greater than the minimum quadratic output torque constraint and the powertrain is operating to react tractive torque during a regenerative operation.