METHOD FOR MANAGING ELECTRIC POWER IN A POWERTRAIN SYSTEM

• US 20090115351A1
• Filed: 10/19/2008
• Published: 05/07/2009
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Heap, Anthony H., Cawthorne, William R.
• Granted Patent: US 8,847,426 B2
• Time in Patent Office: Days
• US Class Current: 307/10.100
• CPC Class Codes: B60K 6/38 characterised by the driveline clutches shift clutches within the gearing or transmission B60K6/36 , B60K6/54
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• 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 2510/02 Clutches
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A powertrain system includes a transmission operative to transfer power between a plurality of power actuators and an output member, and an energy storage device. A method for controlling the powertrain system includes establishing a first set of electric power limits and a second set of electric power limits for the energy storage device, determining a preferred input power from a first power actuator based upon the first set of electric power limits, determining a first set of power constraints for constraining input power from the first power actuator and a second set of power constraints for constraining output power from the output member based upon a second set of electric power limits, and controlling operation of the powertrain system based upon the preferred input power, the first set of power constraints, and the second set of power constraints.

Claims

1. Method for controlling a powertrain system comprising a transmission operative to transfer power between a plurality of power actuators and an output member, and an energy storage device, the method comprising:

establishing a first set of electric power limits and a second set of electric power limits for the energy storage device;

determining a preferred input power from a first power actuator based upon the first set of electric power limits;

determining a first set of power constraints for constraining input power from the first power actuator and a second set of power constraints for constraining output power from the output member based upon a second set of electric power limits; and

controlling operation of the powertrain system based upon the preferred input power, the first set of power constraints, and the second set of power constraints.

2. The method of claim 1, further comprising:

determining a third set of electric power limits; and

determining a first set of power constraints for constraining input power from the first power actuator and a second set of power constraints for constraining output power from the output member based upon the second set of electric power limits and the third set of electric power limits.

3. The method of claim 2, wherein the first set of power constraints for constraining input power from the first power actuator and the second set of power constraints for constraining output power from the output member are utilized in closed loop control.

4. The method of claim 2, wherein the second set of electric power limits are more constrained than the first set of electric power limits and less constrained than the third set of electric power limits.

5. The method of claim 1, further comprising establishing a third set of electric power limits comprising voltage-based electric power limits;

and a second set of power constraints for constraining output power from the output member based upon the second set of electric power limits and the third set of electric power limits.

6. The method of claim 5, further comprising determining an engine start profile based upon the third set of electric power limits.

7. The method of claim 5, wherein the voltage-based electric power limits are based upon an available amount of power that can be delivered by the energy storage device before reaching one of a minimum permissible voltage for operating the energy storage device and maximum permissible voltage for operating the energy storage device.

8. The method of claim 1, wherein the first set of electric power limits are based upon desired electric power levels for operating the energy storage device.

9. The method of claim 1, wherein the second set of electric power limits are based upon long-term battery durability.

10. The method of claim 1, wherein the first set of electric power limits and the second set of electric power limits for the energy storage device are determined based upon at least one of a state of charge of the energy storage device, a temperature of the energy storage device, and a throughput of the energy storage device.

11. Method for controlling a powertrain system comprising an engine, a second torque machine, a transmission device and an energy storage device, the transmission device operative to transfer power between the engine, the second torque machine, and the output member to generate an output torque, the method comprising:

establishing predicted electric power limits, long-term electric power limits, and short-term electric power limits for the energy storage device;

determining a preferred input speed from the engine, a preferred input torque from the engine, a preferred engine state, and a preferred transmission operating range state utilizing the predicted electric power limits;

determining a first set of input torque constraints for constraining input torque from the engine and a first set of output torque constraints for constraining output torque of the output member based upon the long-term electric power limits and the short-term electric power limits; and

controlling operation of the powertrain system based upon the preferred input speed, the preferred input torque, the preferred engine state, the preferred transmission operating range state, the first set of input torque constraints, and the first set of output torque constraints.

12. The method of claim 11, wherein the first set of input torque constraints and the first set of output torque constraints are utilized in closed loop control.

13. The method of claim 11, wherein the predicted electric power limits comprise a more constrained range of battery output power levels than the long-term electric power limits and the short-term electric power limits.

14. The method of claim 11, further comprising:

establishing voltage-based electric power limits;

determining a maximum output torque of the transmission based upon the voltage-based electric power limits; and

controlling operation of the powertrain system based upon the maximum output torque of the transmission.

15. The method of claim 14, wherein the voltage-based electric power limits are based upon an available amount of power that can be delivered by the energy storage device before reaching a minimum and maximum permissible voltage for operating the energy storage device.

16. The method of claim 11, further comprising:

monitoring an operator torque request;

utilizing the predicted electric power limits to determine a range of permissible motor torques; and

determining the preferred input torque from the engine based upon the operator torque request and the range of permissible motor torques.

17. The method of claim 11, further comprising controlling the position of the engine throttle based upon the predicted electric power limits.

18. The method of claim 11, further comprising controlling combustion timing utilizing the long-term and short-term electric power limits.

19. The method of claim 11, wherein a first set of electric power limits and a second set of electric power limits for the energy storage device are determined based upon at least one of a state of charge of the energy storage device, a temperature of the energy storage device, and throughput of the energy storage device.

20. Method for managing electric power in a powertrain system comprising a hybrid transmission operative to transfer power between an engine, first and second torque machines connected to an engine storage device, and an output member, the method comprising:

establishing predicted power limits, long-term power limits, short-term power limits, and voltage-based power limits for the energy storage device;

determining a preferred input speed from the engine, a preferred input torque from the engine, a preferred engine state, and a preferred transmission operating range state utilizing the predicted power limits;

determining a first set of input torque constraints for constraining input torque from the engine and a first set of motor torque constraints for constraining motor torques of the first and second torque machines based upon the long-term power limits and the short term power limits; and

determining maximum motor torques output from the first and second torque machines based upon the voltage-based power limits.