Method and apparatus for controlling hybrid electric vehicles

• US 8,517,892 B2
• Filed: 08/08/2011
• Issued: 08/27/2013
• Est. Priority Date: 08/08/2011
• Status: Active Grant

• Current Assignee: BAE Systems Controls Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Controls Incorporated (BAE Systems Plc)
• Inventors: Matthews, Derek, Pancheri, Brendan, HISSONG, Erin, Schulte, Jurgen, MUGGEO, Filippo
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US13/205,166
• Publication Number:
  US 20130040778A1
• Time in Patent Office: 750 Days
• Field of Search: 701/22, 477/5
• US Class Current: 477/5
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/023 Fluid clutches
• CPC Class Codes: B60W 10/026 of lock-up 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 20/14 in conjunction with braking regeneration
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2030/1809 Without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: B60Y 2400/426 : Hydrodynamic couplings, e.g. torque converters
• CPC Class Codes: F16H 2045/002 : comprising a clutch between prime mover and fluid gearing
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

A method for operating an engine and an integrated starter/generator/motor (ISGM) disposed in a hybrid electric vehicle, which includes launch and deceleration processes. The ISGM is used to both launch the vehicle and start the engine. The deceleration process includes operating a first clutch to disengage the engine from the ISGM during an initial phase, and engaging a second clutch during the initial phase to direct substantially all regenerative energy to provide the only source of electrical energy to recharge the energy storage device.

Claims

1. A method of controlling the operation of a parallel hybrid electric vehicle, comprising an engine, a first clutch, an integrated starter/generator/motor (ISGM) coupled to said engine in accordance with the operating state of said first clutch, a combination of a torque converter and a second clutch connected in parallel therewith, said combination being mechanically coupled between said ISGM and an output drive shaft that propels the vehicle, and an energy storage device electrically coupled to said ISGM, comprising:

transmitting electrical energy from said energy storage device to said ISGM, wherein said ISGM functions as a motor having an output torque, wherein said ISGM is commanded to a predefined percentage of maximum torque of said ISGM;

transmitting a portion of the output torque from said ISGM through said torque converter to the output drive shaft to launch the vehicle; and

operating said first clutch to enable a remaining portion of the output torque of said ISGM to be coupled to said engine to enable the starting of said engine.

2. The method according to claim 1, further comprising detecting a launch even prior to transmitting electrical energy.

3. The method according to claim 1, wherein during the transmitting electrical energy, said ISGM is accelerated to a predefined percentage of the idle speed of said engine.

4. The method according to claim 1, wherein a gear box is positioned between said combination and the output drive shaft.

5. The method according to claim 4, wherein after the starting of said engine, an output torque from said engine is combined with the output torque from said ISGM as the combined torques are transmitted through said torque converter and said gear box to the output drive shaft to accelerate the launching of the vehicle.

6. The method according to claim 1, wherein said second clutch is a lock-up clutch.

7. The method according to claim 6, wherein after the launched vehicle reaches a first threshold speed, said lock-up clutch is engaged to enable the output torque from said engine and said ISGM to be coupled through said lock-up clutch and said gear box to the output drive shaft to provide sufficient power to further accelerate the vehicle.

8. A method for operating an engine in a parallel hybrid vehicle, comprising an engine, a first clutch, an integrated starter/generator/motor (ISGM) coupled to said engine in accordance with the operating state of said first clutch, a combination of a torque converter and a second clutch connected in parallel therewith, said combination being mechanically coupled between the ISGM and an output drive shaft that propels the vehicle, and an energy storage device electrically coupled to the ISGM, comprising:

operating said first clutch to disengage said engine from said ISGM during an initial deceleration phase of a vehicle;

engaging said second clutch during the initial deceleration phase to direct substantially all regenerative energy from the decelerating vehicle therethrough to said ISGM operating as a generator to provide the only source of electrical energy to recharge said energy storage device, and disengaging said second clutch at the later deceleration phase to direct any remaining regenerative energy through said torque converter, and

operating the ISGM as a torsional dampener on the engine during the final deceleration phase.

9. The method as in claim 8, wherein the second clutch is a lock-up clutch.

10. The method as in claim 8, further comprising maintaining the ISGM at an idle speed during the later deceleration phase.

11. The method as in claim 8, further comprising:

defueling the engine during a final deceleration phase in which a velocity is at zero.

12. An engine control system for a parallel hybrid vehicle, the control system comprising:

an internal combustion engine;

a first clutch;

an integrated starter/generator/motor (ISGM) coupled to said internal combustion engine by way of said first clutch;

a rechargeable energy storage system providing electrical energy to said ISGM;

a gearbox coupled to an output drive shaft of the vehicle;

a torque converter mechanically coupled between said ISGM and said gearbox;

a lock-up clutch disposed in parallel with the torque converter, said lock-up clutch having an operation mode in which actuation of said lock-up clutch is controlled independent of operational conditions of said torque converter;

a controller adapted for generating control signals, the control signals controlling operation of said lock-up clutch, said ISGM, said first clutch, and said internal combustion engine,

wherein said controller operates said first clutch to disengage said engine from said ISGM during an initial deceleration phase of said vehicle; and

engages said lock-up clutch during said initial deceleration phase to direct substantially all regenerative energy from said decelerating vehicle therethrough to said ISGM operating as a generator to provide the only source of electric energy to recharge said rechargeable energy storage system, and disengages said lock-up clutch at the later deceleration phase of the vehicle to direct any remaining regenerative energy through said torque converter, and

wherein the controller transmits electrical energy from said rechargeable energy storage system to said ISGM, where said ISGM functions as a motor having an output torque;

transmitting a portion of the output torque from said ISGM through said torque converter to the output drive shaft to launch the vehicle; and

operates said first clutch to enable a remaining portion of the output torque of said ISGM to be coupled to said engine to enable the starting of said engine when launching the vehicle.

13. The system as in claim 12, wherein said ISGM is adapted to operate as a starter during an engine launch operation of a vehicle, as a generator during deceleration of the vehicle, and as a primary traction motor during acceleration and cruising of the vehicle.

14. The system as in claim 12, wherein said rechargeable energy storage system includes at least one of a battery, or a fuel cell.

15. The system as in claim 12, wherein said lock-up clutch is actuated by control of one or more control devices electronically controlled by said control signals received from said controller.

16. A method for controlling the operation of a parallel hybrid electric vehicle, comprising an engine, a first clutch, an integrated starter/generator/motor (ISGM) coupled to said engine in accordance with the operating state of said first clutch, and an energy storage device electrically coupled to the ISGM, comprising:

operating said first clutch to disengage said engine from said ISGM during an initial deceleration phase of a vehicle;

directing substantially all regenerative energy from the decelerating vehicle therethrough to said ISGM operating as a generator to provide the only source of electrical energy to recharge said energy storage device at a first deceleration phase; and

operating said first clutch to couple said engine to said ISGM at a later deceleration phase in which a velocity is below a threshold velocity.

17. The method for operating an engine in a parallel hybrid electric vehicle according to claim 16, further comprising:

using said ISGM to decelerate said engine.

18. A method of controlling the operation of a parallel hybrid electric vehicle, comprising an engine, a first clutch, an integrated starter/generator/motor (ISGM) coupled to said engine in accordance with the operating state of said first clutch, and an energy storage device electrically coupled to said ISGM, comprising:

transmitting electrical energy from said energy storage device to said ISGM using only energy recovered via regenerative energy from deceleration of the parallel hybrid electric vehicle, wherein said ISGM functions as a motor having an output torque;

transmitting a portion of the output torque from said ISGM to the output drive shaft to launch the vehicle; and

operating said first clutch to enable a remaining portion of the output torque of said ISGM to be coupled to said engine to enable the starting of said engine.

19. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 18, further comprising:

detecting a launch event.

20. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 18, wherein during the transmitting of electrical energy, said ISGM is accelerated to a predefined percentage of the idle speed of said engine.

21. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 20, wherein said operating said first clutch occurs when said ISGM is accelerated to a predefined percentage of the idle speed of said engine.

22. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 20, wherein said operating said first clutch occurs prior to said ISGM being accelerated to a predefined percentage of the idle speed of said engine.

23. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 20, further comprising:

receiving a torque command;

comparing said received torque command with a peak torque of said ISGM, wherein said operating said first clutch is based upon said comparing.

24. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 20, further comprising:

controlling a fuel supply to said engine at least based upon the acceleration of said ISGM.

25. The method of controlling the operation of a parallel hybrid electric vehicle according to claim 24, further comprising accelerating said ISGM until a second predefined percentage of idle speed of said engine, wherein said controlling is performed after said ISGM reaches said second predefined percentage of idle speed of said engine.