Method for managing electric power in a powertrain system

• US 8,847,426 B2
• Filed: 10/19/2008
• Issued: 09/30/2014
• Est. Priority Date: 11/02/2007
• Status: Expired due to Fees

• 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 Group LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Cawthorne, William R.
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US12/253,985
• Publication Number:
  US 20090115351A1
• Time in Patent Office: 2,172 Days
• Field of Search: 307/9.1, 307/10.1, 477/3, 477/7
• US Class Current: 307/9.1
• 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:

regularly establishing a first set of electric power limits and a second set of electric power limits for the energy storage device, said first set of electric power limits comprising a first minimum and a first maximum electric power limit, said second set of electric power limits comprising a second minimum and a second maximum electric power limit;

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

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

controlling operation of the powertrain system responsive to the preferred input torque, the first set of power constraints, and the second set of power constraints.

2. The method of claim 1, further comprising:

regularly determining a third set of electric power limits, said third set of electric power limits comprising a third minimum and a third maximum electric power limit; and

determining the first set of power constraints for constraining the input power from the first power actuator and determining the second set of power constraints for constraining the 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 the input torque from the first power actuator and the second set of power constraints for constraining the output torque 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 regularly establishing a third set of electric power limits comprising voltage-based electric power limits, said third set of electric power limits comprising a third minimum and a third maximum electric power limit;

and determining the second set of power constraints for constraining output torque 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 motor torque profile for starting the engine without exceeding a maximum motor torque, said maximum motor torque determined to maintain battery output power less than a maximum voltage-based electric power limit during engine starting 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 electric 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 an amp-hour throughput of the energy storage device.

11. The method of claim 1, wherein controlling operation of the powertrain system based upon the preferred input torque, the first set of power constraints, and the second set of power constraints comprises controlling the first power actuator responsive to the preferred input power constrained by the first power constraints and controlling the remaining power actuators responsive to the second set of power constraints.