SYSTEM CONSTRAINTS METHOD OFCONTROLLING OPERATION OF AN ELECTRO-MECHANICAL TRANSMISSION WITH AN ADDITIONAL CONSTRAINT RANGE

• US 20090118087A1
• Filed: 09/26/2008
• Published: 05/07/2009
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group 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., Hsieh, Tung-Ming
• Granted Patent: US 8,073,602 B2
• Time in Patent Office: Days
• US Class Current: 477/15
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/525 Temperature of converter or components thereof
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/0275 Clutch torque
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/1025 Input torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/105 : Output torque
• 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: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A method for controlling an electromechanical transmission mechanically coupled to first and second electric machines to transmit power to an output member includes determining motor torque constraints and battery power constraints. A preferred output torque to an output member is determined that is achievable within the motor torque constraints, within a range for an additional torque input and based upon the battery power constraints.

Claims

1. A method for controlling an electromechanical transmission mechanically coupled to first and second electric machines to transmit power to an output member, the method comprising:

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

determining battery power constraints for an electrical energy storage device electrically connected to the first and second electric machines;

determining a range for an additional torque input to the electro-mechanical transmission; and

determining a preferred output torque to the output member of the electromechanical transmission that is achievable within the motor torque constraints, is achievable within the range of the additional torque input, and is based upon the battery power constraints.

2. The method of claim 1, wherein the preferred output torque comprises a commanded output torque to the output member in response an operator torque request.

3. The method of claim 2, wherein the preferred output torque comprises a maximum tractive torque to the output member.

4. The method of claim 2, wherein the preferred output torque comprises a maximum regenerative torque to the output member.

5. The method of claim 1, wherein the additional torque input comprises an engine input torque.

6. The method of claim 1, wherein the additional torque input comprises a clutch reactive torque.

7. The method of claim 1, further comprising controlling operation of the electromechanical transmission and the first and second electric machines to achieve the preferred output torque at the output member based upon the motor torque constraints, the range of the additional torque input and the battery power constraints.

8. The method of claim 7, further comprising determining a preferred output torque to the output member of the electromechanical transmission that is achievable within the range of the additional torque input and that minimizes a violation of a maximum battery power constraint when the additional torque input is achievable within the motor torque constraints and the additional torque input exceeds the maximum battery power constraint.

9. The method of claim 7, further comprising determining a preferred output torque to the output member of the electromechanical transmission that is achievable within the range of the additional torque input and is constrained by a maximum battery power constraint when the additional torque input is achievable within the motor torque constraints and the additional torque input is achievable within the maximum battery power constraint.

10. The method of claim 7, further comprising limiting the preferred output torque to the output member of the electromechanical transmission to an output torque achievable within the motor torque constraints and achievable within the battery power constraints.

11. The method of claim 10, wherein the maximum battery power constraint comprises a maximum battery discharging power.

12. The method of claim 10, wherein the minimum battery power constraint comprises a minimum battery charging power.

13. The method of claim 1, wherein the additional torque input comprises an input torque to an input shaft from an internal combustion engine mechanically coupled to the electromechanical transmission.

14. The method of claim 1, wherein the additional torque input comprises torque transfer across an applied torque transfer clutch in the transmission.

15. The method of claim 1, further comprising:

formulating mathematical equations representing maximum and minimum motor torque constraints for the first and second electric machines and representing maximum and minimum battery power constraints;

formulating a mathematical equation representing the output torque;

formulating mathematical equations representing the range for the additional torque input;

transforming the mathematical equations representing the maximum and minimum battery power constraints to equations of concentric circles having respective radii;

transforming the mathematical equations representing the maximum and minimum motor torque constraints for the first and second electric machines to equations comprising lines;

transforming the mathematical equations representing the range for the additional torque input to equations comprising lines; and

transforming the mathematical equation representing the output torque to an equation comprising a line.

16. The method of claim 15, further comprising:

determining at least one transformed achievable output torque based upon the transformed motor torque constraints for the first and second electric machines, the transformed battery power constraints, and the transformed range for the additional torque input;

determining a transformed achievable maximum output torque from the electromechanical transmission; and

,

retransforming the transformed achievable maximum output torque to determine preferred motor torques for the first and second electric machines.

17. The method of claim 15, comprising calculating at least one intersection of the transformed mathematical equations representing the maximum and minimum battery power constraints, the transformed mathematical equations representing the maximum and minimum motor torque constraints for the first and second electric machines, the transformed mathematical equations representing the range for the additional torque input, and the transformed mathematical equation representing the output torque.