CONTROL SYSTEM FOR A HYBRID POWERTRAIN SYSTEM

• US 20080300743A1
• Filed: 11/15/2007
• Published: 12/04/2008
• Est. Priority Date: 11/28/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Conlon, Brendan M., Holmes, Alan G., Tate, Edward D. JR., Rask, Eric M.
• Granted Patent: US 8,234,025 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• 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 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 10/26 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: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• 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 2200/0043 the gear ratios comprising four forward speeds
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/2041 with four engaging means
• CPC Class Codes: F16H 2200/2043 with five engaging means
• 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: Y10S 903/946 Characterized by control of driveline clutch

Abstract

A control system for a hybrid powertrain determines operator demands, a powertrain operating state, and operating conditions based upon the inputs; selects an operating strategy based upon the operator demands, the powertrain operating state, and the operating conditions; determines a preferred powertrain operating state; and controls the powertrain to the preferred powertrain operating state based upon the selected operating strategy, the operator demands and the operating conditions.

Claims

1. A powertrain system for a vehicle, comprising:

an engine;

an electrical energy storage system including an electrical energy storage device selectively electrically coupled to a remote electric power source;

a transmission including a transmission input member operatively connected to the engine, a first electric machine operatively connected to a transmission output member, a second electric machine operatively connected to the transmission input member, said first and second electric machines electrically-operatively coupled to the electrical energy storage system; and

a control system signally connected to a plurality of inputs and operatively connected to a plurality of actuators, said control system operative to execute program code to control the actuators to operate the engine and the transmission, the program code comprising

a) determining operator demands, a powertrain operating state, and operating conditions based upon the inputs,

b) selecting an operating strategy based upon the operator demands, the powertrain operating state, and the operating conditions,

c) determining a preferred powertrain operating state, and

d) controlling the powertrain to the preferred powertrain operating state based upon the selected operating strategy, the operator demands and the operating conditions.

2. The powertrain system of claim 1, wherein the operating strategy comprises one of a charge depletion strategy, a charge sustaining strategy, and an electric vehicle range maximization strategy.

3. The powertrain system of claim 2, wherein the operating strategy selected comprises the charge depletion strategy and the preferred powertrain operating state determined comprises an electric vehicle operating state.

4. The powertrain system of claim 3, wherein the powertrain is permanently configured as a series hybrid powertrain.

5. The powertrain system of claim 3, wherein the powertrain is selectively configured as a series hybrid powertrain.

6. The powertrain system of claim 5, wherein:

the transmission further comprises

a planetary gear set including first, second and third gear members,

a transmission case,

said first gear member connected to said second electric machine,

said second gear member connected to said transmission output member,

a first selectively engageable torque transfer device between said third gear member and said transmission case,

a second selectively engageable torque transfer device between said third gear member and said first electric motor,

a third selectively engageable torque transfer device operable when engaged to connect said first electric motor and said transmission input member; and

controlling the powertrain to the preferred powertrain operating state comprises one of a) controlling said first selectively engageable torque transfer device engaged, said second and third selectively engageable torque transfer devices disengaged, and said second electric machine to provide torque, and b) controlling said second selectively engageable torque transfer device engaged, said first and third selectively engageable torque transfer devices disengaged, and said first and second electric machines to provide torque.

7. The powertrain system of claim 3, wherein determining the preferred powertrain operating state is based upon one of an operator preference and a geographic location of the vehicle.

8. The powertrain system of claim 7, wherein the geographic location of the vehicle comprises one of an area whereat powertrain operating states are restricted to an electric vehicle operating state and an area identified by an operator.

9. The powertrain system of claim 2, wherein:

the operating strategy selected comprises the charge depletion strategy;

the program code further comprises determining a preferred electric power charge/discharge rate, and determining a preferred engine state and selectively operating the engine based upon said preferred electric power charge/discharge rate; and

controlling the powertrain to the preferred powertrain operating state is further based upon the preferred electric power charge/discharge rate and the preferred engine state.

10. The powertrain system of claim 9, wherein the preferred powertrain operating state comprises one of an electric vehicle operating state and an electric vehicle with electric charging operating state, and combinations thereof.

11. The powertrain system of claim 10, wherein the powertrain is permanently configured as a series hybrid powertrain.

12. The powertrain system of claim 10, wherein the powertrain is selectively configured as a series hybrid powertrain.

13. The powertrain system of claim 12, wherein:

the transmission further comprises

a planetary gear set including first, second and third gear members,

a transmission case,

said first gear member connected to said second electric machine,

said second gear member connected to said transmission output member,

a first selectively engageable torque transfer device between said third gear member and said transmission case,

a second selectively engageable torque transfer device between said third gear member and said first electric motor,

a third selectively engageable torque transfer device operable when engaged to connect said first electric motor and said transmission input member; and

controlling the powertrain to the preferred powertrain operating state comprises one of a) controlling said first selectively engageable torque transfer device engaged, said second and third selectively engageable torque transfer devices disengaged, and said second electric machine to provide torque, and b) controlling said second selectively engageable torque transfer device engaged, said first and third selectively engageable torque transfer devices disengaged, and said first and second electric machines to provide torque.

14. The powertrain system of claim 9, wherein the preferred electric power charge/discharge rate comprises a predetermined minimum discharge rate.

15. The powertrain system of claim 14, wherein the predetermined minimum discharge rate is predetermined based upon at least one of an operator input comprising a distance, an operator input comprising a destination, an operator driving style, and an operator-selected drive mode.

16. The powertrain system of claim 14, wherein the predetermined minimum discharge rate is predetermined based upon occurrence of a predetermined trip.

17. The powertrain system of claim 16, wherein the predetermined minimum discharge rate is adjusted based upon vehicle elevation during said predetermined trip.

18. The powertrain system of claim 16, wherein a global positioning system integrated into an operator interface device of the vehicle is utilized to determine the occurrence of the predetermined trip.

19. The powertrain system of claim 14, wherein the predetermined minimum discharge rate is adjusted based upon costs of fuel and electricity.

20. The powertrain system of claim 2, wherein:

the operating strategy selected comprises the charge sustaining strategy;

the program code further comprises determining state of charge of the electrical energy storage device, and setting a preferred charge/discharge rate to effect an average state of charge of the electrical energy storage device at a charge sustaining target value; and

controlling the powertrain to the preferred powertrain operating state is further based upon the charge/discharge rate and preferred electric power charge/discharge rate and the state of charge of the electrical energy storage device.

21. The powertrain system of claim 20, wherein the charge sustaining target value varies with vehicle location.

22. The powertrain system of claim 20, wherein the charge sustaining target value is increased subsequent to termination of an initial charge depleting strategy.

23. The powertrain system of claim 20, wherein the preferred powertrain operating state comprises one of an electric vehicle operating state and an electric vehicle with electric charging operating state, and combinations thereof.

24. The powertrain system of claim 23, wherein the powertrain is permanently configured as a series hybrid powertrain.

25. The powertrain system of claim 23 wherein the powertrain is selectively configured as a series hybrid powertrain.

26. The powertrain system of claim 25, wherein:

the transmission further comprises

a planetary gear set including first, second and third gear members,

a transmission case,

said first gear member connected to said second electric machine,

said second gear member connected to said transmission output member,

a first selectively engageable torque transfer device between said third gear member and said transmission case,

a second selectively engageable torque transfer device between said third gear member and said first electric motor,

a third selectively engageable torque transfer device operable when engaged to connect said first electric motor and said transmission input member; and

controlling the powertrain to the preferred powertrain operating state comprises one of a) controlling said first selectively engageable torque transfer device engaged, said second and third selectively engageable torque transfer devices disengaged, and said second electric machine to provide torque, and b) controlling said second selectively engageable torque transfer device engaged, said first and third selectively engageable torque transfer devices disengaged, and said first and second electric machines to provide torque.

27. The powertrain system of claim 1, wherein the preferred powertrain operating state comprises one of an electric vehicle operating state, an electric vehicle operating state with electric charging, and an electrical charging operating state.

28. The powertrain system of claim 1 wherein the program code further comprises compelling engine operation when available electrical power from the electrical energy storage device is less than a predetermined electrical power.

29. The powertrain system of claim 1 wherein the program code further comprises compelling engine operation when an operating temperature of at least one of the first and second electric machines exceeds a predetermined temperature.

30. The powertrain system of claim 1 wherein the program code further comprises periodically compelling engine operation to exercise engine components.