Method and apparatus to determine a preferred output torque for operating a hybrid transmission in a continuously variable mode

• US 8,112,207 B2
• Filed: 10/21/2008
• Issued: 02/07/2012
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: Bayerische Motoren Werke AG, GM Global Technology Operations LLC (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Hsieh, Tung-Ming
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): Do, Truc M
• Application Number:
  US12/254,898
• Publication Number:
  US 20090118950A1
• Time in Patent Office: 1,204 Days
• Field of Search: 701/22, 701/51, 701/54, 477/181
• US Class Current: 701/54
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• 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 20/30 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 2510/105 Output torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• 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 2200/201 with three sets of orbital gears
• CPC Class Codes: F16H 2200/2041 with four engaging means
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration

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 machine in a continuously variable 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 first and second torque machines and an energy storage device connected thereto, the hybrid transmission operative to transfer power between an input member and an output member and the first and second torque machines in a continuously variable 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 first and second torque machines;

determining a first relationship comprising linear output torque constraints correlated to the motor torque constraints for the first and second torque machines and clutch reactive torque constraints;

determining a second relationship comprising quadratic output torque constraints correlated to 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

simultaneously solving the first and second relationships to determine an output torque to the output member responsive to the preferred output torque and achievable within 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 comprising an operator input to a brake pedal, and determining an output torque range to the output member responsive to the preferred output torque and achievable within 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 within 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 within 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 within 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, wherein determining the second relationship comprises calculating said quadratic output torque constraints in accordance with the following relationship:

8. The method of claim 1, wherein simultaneously solving the first and second relationships comprises:

transforming the first relationship from a first coordinate system to a second coordinate system;

translating the second relationship from a third coordinate system to the second coordinate system; and

wherein simultaneously solving the first and second relationships comprises simultaneously solving the first relationship transformed to the second coordinate system and the second relationship translated to the second coordinate system.

9. Method for controlling an electro-mechanical transmission including first and second electric machines and an electrical energy storage device connected thereto, the electro-mechanical transmission operative to transfer power between an input member and an output member and the first and second electric machines, 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 relationship comprising output torque constraints corresponding to the motor torque constraints for the first and second electric machines and clutch reactive torque constraints;

determining a second relationship comprising output torque constraints corresponding to 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

simultaneously solving the first and second relationships to determine an output torque responsive to the preferred operator torque request and achievable in response to 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 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.

10. The method of claim 9, comprising determining the preferred output torque in response to an operator torque request.

11. The method of claim 9, 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 in response to 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 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.

12. The method of claim 11, 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 in response to 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 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.

13. The method of claim 12, 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 in response to 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 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.

14. The method of claim 13, further comprising determining an output torque to the output member responsive to the preferred output torque that is achievable in response to 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 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 minimizes power flow from the energy storage device to the torque machine.

15. The method of claim 9, wherein determining the second relationship comprises calculating the output torque constraints in accordance with the following relationship:

16. The method of claim 9, wherein simultaneously solving the first and second relationships comprises:

transforming the first relationship from a first coordinate system to a second coordinate system;

translating the second relationship from a third coordinate system to the second coordinate system; and

wherein simultaneously solving the first and second relationships comprises simultaneously solving the first relationship transformed to the second coordinate system and the second relationship translated to the second coordinate system.

17. Method for controlling a hybrid transmission including electric machines and an energy storage device connected thereto, the electro-mechanical transmission operative 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 first 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 a first relationship including maximum and minimum linear output torque constraints correlated to the motor torque constraints for the electric machines and clutch reactive torque constraints;

determining a second relationship including maximum and minimum quadratic output torque constraints correlated to the power constraints from the energy storage device and the first relationship between the power from the energy storage device and the output torque of the transmission device; and

simultaneously solving the first relationship and the second relationship to determine an output torque responsive to the preferred output torque and achievable within the maximum and minimum linear torque constraints and the maximum and minimum quadratic output torque constraints.