Method and apparatus for starting an engine in a hybrid vehicle

• US 8,903,581 B2
• Filed: 02/04/2013
• Issued: 12/02/2014
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: GE Hybrid Technologies, LLC
• Original Assignee: MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)
• Inventors: Bouchon, Nicolas Louis
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Nolan, Peter D
• Application Number:
  US13/758,019
• Publication Number:
  US 20130143715A1
• Time in Patent Office: 666 Days
• Field of Search: 701/22, 701/51, 701/67, 180/65.245, 180/65.275, 180/65.28, 180/65.6
• US Class Current: 701/22
• 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, comprising:

generating a first control signal to be communicated to a clutch of the hybrid vehicle, the first control signal operable to cause the clutch to couple an engine of the hybrid vehicle to an electric motor of the hybrid vehicle such that a load is applied to the electric motor, the load causing;

the electric motor to decelerate to a reduced rotational speed over a motor deceleration time period; and

a starting torque to be supplied to the engine for starting the engine; and

generating, during the motor deceleration time period, a second control signal to be communicated to an automatic transmission of the hybrid vehicle, the second control signal operable to cause the automatic transmission to shift to a target gear ratio selected such that a driving torque supplied by the electric motor at the reduced rotational speed during the motor deceleration time period is sufficient to maintain a desired acceleration of the hybrid vehicle.

2. The method of claim 1, wherein the first control signal is generated in response to a determination that an operating condition of the hybrid vehicle meets a criterion for starting the engine.

3. The method of claim 2, wherein the second control signal is generated in response to the determination that the operating condition of the hybrid vehicle meets the criterion for starting the engine.

4. The method of claim 2, wherein the determination that an operating condition of the hybrid vehicle meets the criterion for starting the engine comprises at least one of:

a determination that the rotational speed of the electric motor reaches a reference speed;

a determination that the hybrid vehicle reaches a reference velocity;

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

a determination that a voltage at which electrical energy supplied to the electric motor reaches a reference minimum level.

5. The method of claim 2, wherein:

the first control signal is generated a first time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine; and

the second control signal is generated a second time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine.

6. The method of claim 5, wherein the first and second time periods are selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

7. The method of claim 2, further comprising generating an engine start signal in response to the operating condition of the hybrid vehicle meeting the criterion for starting the engine.

8. The method of claim 7, wherein the engine start signal comprises 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.

9. The method of claim 8, wherein the engine start signal is generated a third time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine, the third time period being selected such that the engine is allowed sufficient time to reach a rotational speed corresponding to the rotational speed of the electric motor.

10. The method of claim 1, wherein the first control signal is operable to cause the clutch to couple the engine to the electric motor by causing the clutch to move from a disengaged state to an engaged state, the clutch being located between the engine and the electric motor.

11. The method of claim 10, wherein the first control signal comprises a time-varying amplitude representing a desired amount of engagement of the clutch between the disengaged state and the engaged state in order to control an amount of slippage of the clutch when coupling the engine to the electric motor.

12. The method of claim 1, wherein:

the second control signal is operable to cause the automatic transmission to shift to the target gear ratio from a previous gear ratio; and

the target gear ratio is higher than the previous gear ratio.

13. An apparatus for starting an engine in a hybrid vehicle, comprising:

a controller configured to communicate with a clutch and an automatic transmission of the hybrid vehicle, the controller operable to;

generate a first control signal to be communicated to the clutch, the first control signal operable to cause the clutch to couple the engine of the hybrid vehicle to an electric motor of the hybrid vehicle such that a load is applied to the electric motor, the load causing;

the electric motor to decelerate to a reduced rotational speed over a motor deceleration time period; and

a starting torque to be supplied to the engine for starting the engine; and

generate, during the motor deceleration time period, a second control signal to be communicated to the automatic transmission of the hybrid vehicle, the second control signal operable to cause the automatic transmission to shift to a target gear ratio selected such that a driving torque supplied by the electric motor at the reduced rotational speed during the motor deceleration time period is sufficient to maintain a desired acceleration of the hybrid vehicle.

14. The apparatus of claim 13, wherein the first control signal is generated in response to a determination that an operating condition of the hybrid vehicle meets a criterion for starting the engine.

15. The apparatus of claim 14, wherein the second control signal is generated in response to the determination that the operating condition of the hybrid vehicle meets the criterion for starting the engine.

16. The apparatus of claim 14, wherein the determination that an operating condition of the hybrid vehicle meets the criterion for starting the engine comprises at least one of:

a determination that the rotational speed of the electric motor reaches a reference speed;

a determination that the hybrid vehicle reaches a reference velocity;

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

a determination that a voltage at which electrical energy supplied to the electric motor reaches a reference minimum level.

17. The apparatus of claim 14, wherein:

the first control signal is generated a first time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine; and

the second control signal is generated a second time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine.

18. The apparatus of claim 17, wherein the first and second time periods are selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

19. The apparatus of claim 14, wherein the controller is further operable to generate an engine start signal in response to the operating condition of the hybrid vehicle meeting the criterion for starting the engine.

20. The apparatus of claim 19, wherein the engine start signal comprises 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.

21. The apparatus of claim 20, wherein the engine start signal is generated a third time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine, the third time period being selected such that the engine is allowed sufficient time to reach a rotational speed corresponding to the rotational speed of the electric motor.

22. The apparatus of claim 13, wherein the first control signal is operable to cause the clutch to couple the engine to the electric motor by causing the clutch to move from a disengaged state to an engaged state, the clutch being located between the engine and the electric motor.

23. The apparatus of claim 22, wherein the first control signal comprises a time-varying amplitude representing a desired amount of engagement of the clutch between the disengaged state and the engaged state in order to control an amount of slippage of the clutch when coupling the engine to the electric motor.

24. The apparatus of claim 13, wherein:

the second control signal is operable to cause the automatic transmission to shift to the target gear ratio from a previous gear ratio; and

the target gear ratio is higher than the previous gear ratio.

25. A hybrid vehicle, comprising:

an engine;

an electric motor;

a clutch located between the engine and the electric motor;

an automatic transmission; and

a controller configured to communicate with the clutch and the automatic transmission, the controller operable to;

generate a first control signal to be communicated to the clutch, the first control signal operable to cause the clutch to couple the engine to the electric motor such that a load is applied to the electric motor, the load causing;

the electric motor to decelerate to a reduced rotational speed over a motor deceleration time period; and

a starting torque to be supplied to the engine for starting the engine; and

generate, during the motor deceleration time period, a second control signal to be communicated to the automatic transmission, the second control signal operable to cause the automatic transmission to shift to a target gear ratio selected such that a driving torque supplied by the electric motor at the reduced rotational speed during the motor deceleration time period is sufficient to maintain a desired acceleration of the hybrid vehicle.

26. The hybrid vehicle of claim 25, wherein the first control signal is generated in response to a determination that an operating condition of the hybrid vehicle meets a criterion for starting the engine.

27. The hybrid vehicle of claim 26, wherein the second control signal is generated in response to a determination that the operating condition of the hybrid vehicle meets the criterion for starting the engine.

28. The hybrid vehicle of claim 26, wherein the determination that an operating condition of the hybrid vehicle meets the criterion for starting the engine comprises at least one of:

a determination that the rotational speed of the electric motor reaches a reference speed;

a determination that the hybrid vehicle reaches a reference velocity;

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

a determination that a voltage at which electrical energy supplied to the electric motor reaches a reference minimum level.

29. The hybrid vehicle of claim 26, wherein:

the first control signal is generated a first time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine; and

the second control signal is generated a second time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine.

30. The hybrid vehicle of claim 29, wherein the first and second time periods are selected such that a substantially constant acceleration of the hybrid vehicle is maintained while starting the engine.

31. The hybrid vehicle of claim 26, wherein the controller is further operable to generate an engine start signal in response to the operating condition of the hybrid vehicle meeting the criterion for starting the engine.

32. The hybrid vehicle of claim 31, wherein the engine start signal comprises at least one of:

an ignition signal for controlling ignition of the engine;

or

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

33. The hybrid vehicle of claim 32, wherein the engine start signal is generated a third time period after the operating condition of the hybrid vehicle meets the criterion for starting the engine, the third time period being selected such that the engine is allowed sufficient time to reach a rotational speed corresponding to the rotational speed of the electric motor.

34. The hybrid vehicle of claim 25, wherein the first control signal comprises a time-varying amplitude representing a desired amount of engagement of the clutch between the disengaged state and the engaged state in order to control an amount of slippage of the clutch when coupling the engine to the electric motor.

35. The hybrid vehicle of claim 25, wherein:

the second control signal is operable to cause the automatic transmission to shift to the target gear ratio from a previous gear ratio; and

the target gear ratio is higher than the previous gear ratio.