Method and apparatus for starting an engine in a hybrid vehicle

• US 8,387,730 B2
• Filed: 11/30/2006
• Issued: 03/05/2013
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: GE Hybrid Technologies, LLC
• Original Assignee: Azure Dynamics Incorporated
• Inventors: Bouchon, Nicolas Louis
• Primary Examiner(s): Shriver, II, J. Allen
• Assistant Examiner(s): CHIBOGU, CHIEDU A
• Application Number:
  US11/606,481
• Publication Number:
  US 20080132378A1
• Time in Patent Office: 2,287 Days
• Field of Search: 180/65.21, 180/65.25, 180/65.265, 180/65.275, 180/65.28, 180/65.7, 477/3
• US Class Current: 180/65.265
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/16 DC brushless machines
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 50/16 : with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 : using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/12 : responding to state of charge [SoC]
• CPC Class Codes: B60L 58/21 : having the same nominal voltage
• 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 10/10 : including control of change-speed gearings
• CPC Class Codes: B60W 10/101 : Infinitely variable gearings
• CPC Class Codes: B60W 10/11 : Stepped gearings
• CPC Class Codes: B60W 10/115 : with planetary gears
• 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 20/30 : Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2510/0695 : Inertia
• CPC Class Codes: B60W 2510/081 : Speed
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2520/10 : Longitudinal speed
• CPC Class Codes: B60W 2710/021 : Clutch engagement state
• CPC Class Codes: B60W 2710/025 : Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/081 : Speed
• CPC Class Codes: B60W 2710/1005 : Transmission ratio engaged
• CPC Class Codes: B60W 2720/10 : Longitudinal speed
• CPC Class Codes: B60W 30/192 : Mitigating problems related to power-up or power-down of the driveline, e.g. start-up of a cold engine
• CPC Class Codes: B60Y 2200/92 : Hybrid vehicles
• CPC Class Codes: B60Y 2300/192 : Power-up or power-down of the driveline, e.g. start up of a cold engine
• CPC Class Codes: B60Y 2300/42 : Control of clutches
• CPC Class Codes: B60Y 2300/43 : Control of engines
• CPC Class Codes: B60Y 2300/50 : Engine start by use of flywheel kinetic energy
• CPC Class Codes: B60Y 2300/60 : Control of electric machines, e.g. problems related to electric motors or generators
• CPC Class Codes: B60Y 2400/70 : Gearings
• CPC Class Codes: B60Y 2400/72 : Continous variable transmissions [CVT]
• 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 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A method and apparatus for starting an engine in a hybrid vehicle being driven by an electric motor is disclosed. The motor is operably configured to deliver mechanical power through an automatic transmission to at least one vehicle drive wheel to cause an acceleration of the vehicle. The method involves coupling the engine to the motor to cause an inertial load on the motor thus causing the motor to decelerate to a reduced rotational speed to provide a starting torque to the engine for starting the engine, and causing the automatic transmission to change gear ratio to a target gear ratio associated with the reduced rotational speed while causing the motor to decelerate, the motor being operable to deliver increased torque at the reduced rotational speed, thereby generally maintaining the acceleration of the vehicle.

Claims

1. A method for starting an engine in a hybrid vehicle being driven by an electric motor generating a driving torque, the driving torque being coupled through an automatic transmission to deliver the driving torque to at least one vehicle drive wheel of the hybrid vehicle to cause acceleration of the hybrid vehicle, the method comprising:

coupling the engine to the motor to cause an inertial load on the motor thereby causing the motor to decelerate to a reduced rotational speed over a motor deceleration time period in response to receiving a control signal from a controller; and

during said motor deceleration time period, producing a shift signal at the controller to cause the automatic transmission to upshift gear ratio to a target gear ratio that is operable to continue to deliver the driving torque at said reduced rotational speed of the motor thereby maintaining the acceleration of the hybrid vehicle, the motor being operable at said reduced rotational speed to generate increased torque to provide a starting torque for starting the engine while continuing to deliver the driving torque.

2. The method of claim 1 wherein coupling the engine to the motor comprises coupling the engine to the motor when a operating condition of the hybrid vehicle meets a criterion for starting the engine.

3. The method of claim 2 wherein causing the controller to produce said shift signal comprises causing the controller to produce said shift signal when said operating condition of the hybrid vehicle meets said criterion for starting the engine.

4. The method of claim 2 wherein coupling the engine to the motor when said operating condition of the hybrid vehicle meets said criterion for starting the engine comprises coupling the engine to the motor when at least one of:

the rotational speed of the motor reaches a reference speed;

the hybrid vehicle reaches a reference velocity;

a storage element for supplying electrical energy to the motor reaches a reference minimum state of charge; and

a voltage at which said electrical energy is supplied to the motor reaches a reference minimum level.

5. The method of claim 1 wherein the hybrid vehicle comprises a clutch disposed between the motor and the engine, the clutch having a disengaged state for decoupling the engine from the motor and an engaged state for coupling the engine to the motor, and wherein coupling the engine to the motor comprises causing the controller to produce a clutch control signal to cause the clutch to change state from said disengaged state to said engaged state when an operating condition of the hybrid vehicle meets a criterion for starting the engine.

6. The method of claim 5 wherein said clutch control signal is a discrete clutch control signal having first and second states, said clutch being operably configured to change from said disengaged state to said engaged state in response to said clutch control signal having said first state.

7. The method of claim 5 wherein said clutch control signal is a clutch control signal having a time-varying amplitude representing a desired amount of engagement of said clutch between said engaged state and said disengaged state, wherein said clutch control signal controls an amount of slippage of said clutch when coupling the engine to the motor.

8. The method of claim 5 wherein producing said clutch control signal comprises producing said clutch control signal a first time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, and wherein producing said shift signal comprises producing said shift signal a second time period after said operating condition of hybrid vehicle meets said criterion for starting the engine, said first and second time periods being selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

9. The method of claim 2 further comprising causing said controller to produce an engine start signal in response to said operating condition of the hybrid vehicle meeting said criterion for starting the engine.

10. The method of claim 9 wherein causing the controller to produce said engine start signal comprises causing said controller to produce at least one of:

an ignition signal for controlling ignition of the engine;

or

a fuel control signal for causing fuel to be supplied to the engine.

11. The method of claim 9 wherein causing the controller to produce said engine start signal comprises causing the controller to produce said engine start signal a time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, said third time period being sufficient time to permit the engine to reach a rotational speed that generally matches the rotational speed of the motor.

12. The method of claim 1 wherein the automatic transmission is operably configured to provide a plurality of discrete gear ratios and wherein the shift signal is operable to cause the automatic transmission to upshift gear ratio from a first gear ratio to said target gear ratio.

13. The method of claim 1 wherein the automatic transmission is operably configured to provide a continuously variable gear ratio and wherein the shift signal is operable to cause the automatic transmission to upshift gear ratio by an amount sufficient to provide said target gear ratio for delivering the driving torque to the at least one vehicle wheel of the hybrid vehicle.

17. The apparatus of claim 1 wherein said means for coupling the engine to the motor when said operating condition of the hybrid vehicle meets said criterion for starting the engine comprises means for coupling the engine to the motor when at least one of:

the rotational speed of the motor speed reaches a reference speed;

the hybrid vehicle reaches a reference velocity;

a storage element for supplying electrical energy to the motor reaches a reference minimum state of charge; and

a voltage at which said electrical energy is supplied to the motor reaches a reference minimum level.

14. An apparatus for starting an engine in a hybrid vehicle being driven by an electric motor generating a driving torque, the driving torque being coupled through an automatic transmission to deliver the driving torque to at least one drive wheel of the hybrid vehicle to cause acceleration of the hybrid vehicle, the apparatus comprising:

a controller;

means for coupling the engine to the motor to cause an inertial load on the motor thereby causing the motor to decelerate to a reduced rotational speed over a motor deceleration time period, said means for coupling the engine to the motor being responsive to receiving a control signal from the controller; and

said controller being operably configured to produce a shift signal during said motor deceleration time period, said shift signal being operable to cause the automatic transmission to upshift gear ratio to a target gear ratio that is operable to continue to deliver the driving torque at said reduced rotational speed of the motor, the motor being operable to generate increased torque at said reduced rotational speed to provide a starting torque for starting the engine while continuing to deliver the driving torque.

15. The apparatus of claim 14 wherein said means for coupling the engine to the motor comprises means for coupling the engine to the motor when an operating condition of the hybrid vehicle meets a criterion for starting the engine.

16. The apparatus of claim 15 wherein said means for causing the controller to produce said shift signal comprises means for causing the controller to produce said shift signal when said operating condition of the hybrid vehicle meets said criterion for starting the engine.

18. The apparatus of claim 14 wherein the hybrid vehicle comprises a clutch disposed between the motor and the engine, the clutch having a disengaged state for decoupling the engine from the motor and an engaged state for coupling the engine to the motor, and wherein said means for coupling the engine to the motor comprises means for causing the controller to produce a clutch control signal to cause the clutch to change state from said disengaged state to said engaged state when an operating condition of the hybrid vehicle meets a criterion for starting the engine.

19. The apparatus of claim 18 wherein said clutch control signal is a discrete clutch control signal having first and second states, said clutch being operably configured to change from said disengaged state to said engaged state in response to said clutch control signal having said first state.

20. The apparatus of claim 18 wherein said clutch control signal is a clutch control signal having a time-varying amplitude representing a desired amount of engagement of said clutch between said engaged state and said disengaged state, wherein said clutch control signal controls an amount of slippage of said clutch when coupling the engine to the motor.

21. The apparatus of claim 18 wherein said means for producing said clutch control signal comprises means for producing said clutch control signal a first time period after said operating of the hybrid vehicle condition meets said criterion for starting the engine, and wherein said means for producing said shift signal comprises means for producing said shift signal a second time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, said first and second time periods being selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

22. The apparatus of claim 15 further comprising means for causing the controller to produce an engine start signal in response to said operating condition of the hybrid vehicle meeting said criterion for starting the engine.

23. The apparatus of claim 22 wherein said means for causing the controller to produce said engine start signal comprises means for causing the controller to produce at least one of:

an ignition signal for controlling ignition of the engine;

or

a fuel control signal for causing fuel to be supplied to the engine.

24. The apparatus of claim 22 wherein said means for causing the controller to produce said engine start signal comprises means for causing the controller to produce said engine start signal a time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, said time period being sufficient time to permit the engine to reach a rotational speed that generally matches the rotational speed of the motor.

25. The apparatus of claim 14 wherein the automatic transmission is operably configured to provide a plurality of discrete gear ratios and wherein said shift signal is operable to cause the automatic transmission to upshift gear ratio from a first gear ratio to said target gear ratio.

26. The apparatus of claim 14 wherein the automatic transmission is operably configured to provide a continuously variable gear ratio and wherein said shift signal is operable to cause the automatic transmission to upshift gear ratio by an amount sufficient to provide said target gear ratio for delivering the driving torque to the at least one vehicle wheel of the hybrid vehicle.

27. An apparatus for starting an engine in a hybrid vehicle being driven by an electric motor generating a driving torque, the driving torque being coupled through an automatic transmission to deliver the driving torque to at least one drive wheel of the hybrid vehicle of the hybrid vehicle to cause acceleration of the hybrid vehicle, the apparatus comprising a controller operably configured to:

cause the engine to be coupled to the motor to cause an inertial load on the motor thus causing the motor to decelerate to a reduced rotational speed over a motor deceleration time period in response to a control signal produced by the controller; and

produce a shift signal during said motor deceleration time period, said shift signal being operable to cause the automatic transmission to upshift gear ratio to a target gear ratio that is operable to continue to deliver the driving torque at said reduced rotational speed of the motor thereby maintaining the acceleration of the hybrid vehicle, the motor being operable at said reduced rotational speed to generate increased torque to provide a starting torque for starting the engine while continuing to deliver the driving torque.

28. The apparatus of claim 27 wherein said controller is operably configured to cause the engine to be coupled to the motor when a operating condition of the hybrid vehicle meets a criterion for starting the engine.

29. The apparatus of claim 28 wherein said controller is operably configured to produce said shift signal when said operating condition of the hybrid vehicle meets said criterion for starting the engine.

30. The apparatus of claim 28 wherein said controller is operably configured to couple the engine to the motor when at least one of:

the rotational speed of the motor speed reaches a reference speed;

the hybrid vehicle reaches a reference velocity;

a storage element for supplying electrical energy to the motor reaches a reference minimum state of charge; and

a voltage at which said electrical energy is supplied to the motor reaches a reference minimum level.

31. The apparatus of claim 27 wherein the hybrid vehicle comprises a clutch disposed between the motor and the engine, the clutch having a disengaged state for decoupling the engine from the motor and an engaged state for coupling the engine to the motor, and wherein said controller is operably configured to produce a clutch control signal to cause the clutch to change state from said disengaged state to said engaged state when an operating condition of the hybrid vehicle meets a criterion for starting the engine.

32. The apparatus of claim 31 wherein said clutch control signal is a discrete clutch control signal having first and second states, said clutch being operably configured to change from said disengaged state to said engaged state in response to said clutch control signal having said first state.

33. The apparatus of claim 31 wherein said clutch control signal is a clutch control signal having a time-varying amplitude representing a desired amount of engagement of said clutch between said engaged state and said disengaged state, wherein said clutch control signal controls an amount of slippage of said clutch when coupling the engine to the motor.

34. The apparatus of claim 31 wherein said controller is operably configured to produce said clutch control signal a first time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, and wherein said controller is operably configured to produce said shift signal a second time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, said first and second time periods being selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

35. The apparatus of claim 28 wherein said controller is operably configured to produce an engine start signal in response to said operating condition of the hybrid vehicle meeting said criterion for starting the engine.

36. The apparatus of claim 35 wherein said controller is operably configured to produce said engine start signal by producing at least one of:

an ignition signal for controlling ignition of the engine;

or

a fuel control signal for causing fuel to be supplied to the engine.

37. The apparatus of claim 35 wherein said controller is operably configured to produce said engine start signal a time period after said operating condition of the hybrid vehicle meets said criterion for starting the engine, said time period being sufficient time to permit the engine to reach a rotational speed that generally matches the rotational speed of the motor.

38. The apparatus of claim 27 wherein the automatic transmission is operably configured to provide a plurality of discrete gear ratios and wherein said controller is operably configured to cause the automatic transmission to upshift gear ratio from a first gear ratio to said target gear ratio.

39. The apparatus of claim wherein the automatic transmission is operably configured to provide a continuously variable gear ratio and wherein the shift signal is operable to cause the automatic transmission to upshift gear ratio by an amount sufficient to provide said target gear ratio for delivering the driving torque to the at least one vehicle of the hybrid vehicle.