Control system and method for a hybrid electric vehicle

• US 6,196,344 B1
• Filed: 09/10/1999
• Issued: 03/06/2001
• Est. Priority Date: 09/10/1999
• Status: Expired due to Term

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Tamor, Michael Alan
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/394,373
• Time in Patent Office: 543 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/65.8, 180/165, 477/2, 477/3, 477/20, 477/16, 318/139, 318/140, 318/141, 318/153
• US Class Current: 180/65.25
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• 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 10/10 including control of change-speed gearings
• 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 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y10S 903/945 Characterized by control of gearing, e.g. control of transmission ratio

Abstract

Several control methods are presented for application in a hybrid electric vehicle powertrain including in various embodiments an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from the engine and the motor generator coupled to augment torque provided by the engine, an energy storage device coupled to receive energy from and provide energy to the motor/generator, an engine controller (EEC) coupled to control the engine, a transmission controller (TCM) coupled to control the transmission and a vehicle system controller (VSC) adapted to control the powertrain.

Claims

1. In a hybrid electric vehicle powertrain including an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from said engine and said motor/generator coupled to augment torque provided by said engine, an energy storage device coupled to receive energy from and provide energy to said motor/generator and a vehicle system controller (VSC) adapted to control said powertrain, a method for controlling said powertrain comprising:

providing an accelerator position signal to said VSC;

in said VSC, calculating a first desired electric machine torque to reflect a driver-commanded boost or regenerative torque, said first desired electric machine torque being a function of said accelerator position signal;

controlling output torque of said engine at least partly as a function of said accelerator position signal;

in said VSC, calculating a second desired electric machine torque to reflect a battery-charge-maintenance torque; and

controlling said electric machine in view of said first desired electric machine torque and said second desired electric machine torque.

2. A method as recited in claim 1, wherein said powertain further includes and engine controller (EEC) coupled to control said engine, said method further comprising:

providing a first signal from said VSC to said EEC to reflect a driver-commanded boost or regenerative torque of said electric machine; and

providing a second signal from said VSC to said EEC to reflect a battery-charge maintenance torque of said electric machine.

3. A method as recited in claim 2, further comprising:

generating a first desired engine torque signal as a function of said accelerator position signal; and

generating a second desired engine torque signal as a function of said first desired engine torque signal and said second signal.

4. A method as recited in claim 3, wherein said powertrain further includes a transmission controller (TCM) coupled to control said transmission, said method further comprising:

if a transmission shift event is impending or in progress, providing a TCM-desired transmission input torque signal from said TCM to said EEC;

in said EEC, partitioning said TCM-desired transmission input torque signal into a TCM-desired engine torque signal and a TCM-desired electric machine torque signal.

5. A method as recited in claim 4, further comprising:

controlling output torque of said engine in view of said first desired engine control signal and said TCM-desired engine torque signal.

6. A method as recited in claim 5, further comprising:

providing said TCM-desired electric machine torque signal from said EEC to said VSC;

controlling said electric machine in view of said first desired electric machine torque, said second desired electric machine torque and said TCM-desired electric machine torque signal.

7. A method as recited in claim 6, further comprising:

providing a third signal from the EEC to the TCM to reflect a target input torque to said transmission, said target input torque to said transmission being a sum of said driver-commanded boost or regenerative torque, and said second desired engine torque signal.

8. A method as recited in claim 7, further comprising:

providing a fourth signal from the EEC to the TCM to reflect a sum of a total engine output torque and said boost or regenerative torque.

9. In a hybrid electric vehicle powertrain including an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from said engine and said motor/generator coupled to augment torque provided by said engine, an energy storage device coupled to receive energy from and provide energy to said motor/generator, an engine controller (EEC) coupled to control said engine and a vehicle system controller (VSC) adapted to control said powertrain, a method for controlling said powertrain comprising:

providing an accelerator position signal to said VSC;

in said VSC, calculating a first desired electric machine torque to reflect a driver-commanded boost or regenerative torque, said first desired electric machine torque being a function of said accelerator position signal;

providing a modified accelerator position signal from said VSC to said EEC, said modified accelerator position signal reaching 100% before said first accelerator position signal; and

controlling output torque of said engine at least partly as a function of said modified accelerator position signal.

10. A method as recited in claim 9, further comprising:

in said VSC, calculating a second desired electric machine torque to reflect a battery-charge-maintenance torque; and

controlling said electric machine in view of said first desired electric machine torque and said second desired electric machine torque.

11. A method as recited in claim 10, further comprising:

providing a first signal from said VSC to said EEC to reflect a driver-commanded boost or regenerative torque of said electric machine; and

providing a second signal from said VSC to said EEC to reflect a battery-charge maintenance torque of said electric machine.

12. A method as recited in claim 11, further comprising:

generating a first desired engine torque signal as a function of said modified accelerator position signal; and

generating a second desired engine torque signal as a function of said first desired engine torque signal and said second signal.

13. A method as recited in claim 12, wherein said powertrain further includes a transmission controller (TCM) coupled to control said transmission, said method further comprising:

if a transmission shift event is impending or in progress, providing a TCM-desired transmission input torque signal from said TCM to said EEC;

in said EEC, partitioning said TCM-desired transmission input torque signal into a TCM-desired engine torque signal and a TCM-desired electric machine torque signal.

14. A method as recited in claim 13, further comprising:

controlling output torque of said engine in view of said first desired engine control signal and said TCM-desired engine torque signal.

15. A method as recited in claim 14, further comprising:

providing said TCM-desired electric machine torque signal from said EEC to said VSC;

controlling said electric machine in view of said first desired electric machine torque, said second desired electric machine torque and said TCM-desired electric machine torque signal.

16. A method as recited in claim 15, further comprising:

providing a third signal from the EEC to the TCM to reflect a target input torque to said transmission, said target input torque to said transmission being a sum of said driver-commanded boost or regenerative torque, and said second desired engine torque signal.

17. A method as recited in claim 16, further comprising:

providing a fourth signal from the EEC to the TCM to reflect a sum of a total engine output torque and said boost or regenerative torque.

18. In a hybrid electric vehicle powertrain including an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from said engine and said motor/generator coupled to augment torque provided by said engine, an energy storage device coupled to receive energy from and provide energy to said motor/generator, an electronic engine controller (EEC coupled to control said engine and a transmission controller (TCM) coupled to control said transmission, a method for controlling said powertrain comprising:

providing a signal from said EEC to said TCM to reflect a sum of an actual or estimated electric machine torque and an actual or estimated engine output torque;

providing a signal from said TCM to said EEC to reflect a TCM-commanded transmission input torque;

partitioning said TCM-commanded transmission input torque signal into a TCM-commanded engine torque signal and a TCM-commanded electric machine torque signal.

19. A method as recited in claim 18, wherein said powertrain further comprises a vehicle system controller (VSC) adapted to control said powertrain and wherein said TCM-commanded electric machine torque signal is provided from said EEC to said VSC.

20. A method as recited in claim 19, further comprising:

in said VSC, calculating a first desired electric machine torque to reflect a driver-commanded boost or regenerative torque;

in said VSC, calculating a second desired electric machine torque to reflect a battery-charge-maintenance torque; and

controlling said electric machine in view of said first desired electric machine torque, said second desired electric machine torque and said TCM-commanded electric machine torque signal.

21. A method as recited in claim 20, wherein, when a transmission shift is impending or is in progress, said TCM-commanded electric machine torque signal overrrides at least said first desired electric machine torque.