Regenerative vehicle launch

• US 5,637,987 A
• Filed: 12/18/1995
• Issued: 06/10/1997
• Est. Priority Date: 12/18/1995
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Fattic, Gerald T., Stahura, Daniel W., Vukovich, William J.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/573,685
• Time in Patent Office: 540 Days
• Field of Search: 322/11, 322/12, 322/13, 322/14, 322/16, 322/40, 180/65.3, 180/65.5, 290/19, 477/3
• US Class Current: 322/40
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• 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: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• 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: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 2270/602 ABS features related thereto
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 20/40 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 2050/0011 Proportional Integral Differential [PID] controller
• CPC Class Codes: B60W 2050/0012 Feedforward or open loop systems
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• 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 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/914 : Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

A hybrid electric vehicle includes an internal combustion engine, a multi-speed automatic transmission, and an electric machine operable in a motoring mode and a generating mode. A compound planetary gear set operatively couples the engine, transmission and electric machine. The electric machine is operable during periods of vehicle launch to provide a reaction torque for the planetary gearset such that torque is supplied to the input of the transmission and the reaction torque energy is converted to electrical energy for storage in a vehicle battery pack battery. The method employs a combination of open loop torque control and closed loop speed controls responsive to rotational parameters of the vehicle drivetrain including engine speed, electric machine rotor speed and transmission input speed to control the generator torque of the electric machine to thereby produce the reaction torque for accelerating the vehicle and for producing electrical power during the vehicle launch.

Claims

1. A method of launching a vehicle from a substantially static condition, said vehicle having a drivetrain comprising an internal combustion engine including an engine output member, a electric machine including a stator and rotor, and a gear set operatively coupling said internal combustion engine output, said rotor and a gear set output member of said gear set, said gear set output member being operatively coupled to at least one drive wheel for propelling the vehicle, wherein said generator is effective as an electric brake reaction element to control torque transfer between said engine output member and said gear set output member, the method comprising:

detecting a predetermined set of vehicle drivetrain operating parameters;

controlling a torque influencing electric machine parameter to apply an amount of generator torque to the rotor as a function of said predetermined set of vehicle operating parameters thereby converging respective speeds of the rotor and the gear set output member; and

,

when the speeds of the rotor and the gear set output member attain a predetermined speed differential relationship, controlling the rotor speed to the gear set output member speed.

2. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said drivetrain further includes a selectably engageable friction device for directly coupling said gear set output member to said rotor, said method further comprising the step of engaging said friction device while controlling the rotor speed to the gear set output member speed.

3. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said drivetrain further includes a selectably engageable friction device for directly coupling said gear set output member to said engine output member, said method further comprising the step of engaging said friction device while controlling the rotor speed to the gear set output member speed.

4. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said predetermined set of vehicle drivetrain operating parameters comprises engine output member speed, rotor speed and gear set output member speed.

5. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said torque influencing electric machine parameter comprises stator current.

6. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said torque influencing generator parameter comprises electric machine slip speed.

7. A method of launching a vehicle from a substantially static condition as set forth in claim 1 wherein said drivetrain further includes a first selectably engageable friction device for directly coupling said gear set output member to said engine output member, and a second selectably engageable friction device for directly coupling said gear set output member to said rotor, said method further comprising the step of engaging said first and second friction devices while controlling the rotor speed to the gear set output member speed.

8. A method of launching a vehicle from a substantially static condition as set forth in claim 7 wherein said step of engaging said first and second friction devices while controlling the rotor speed to the gear set output member speed occurs only above a predetermined vehicle speed.

9. A method of launching a vehicle from a substantially static condition as set forth in claim 7 wherein said step of engaging said first and second friction devices while controlling the rotor speed is effectuated by fully engaging said second friction device and progressively engaging said first friction device from an initial engagement pressure to a final engagement pressure.

10. A method of launching a vehicle from a substantially static condition, said vehicle having a drivetrain comprising an internal combustion engine including an engine output member, a electric machine including a rotor, and a gear set operatively coupling said internal combustion engine output, said rotor and a gear set output member of said gear set, said gear set output member being operatively coupled to at least one drive wheel for propelling the vehicle, a first selectably engageable friction device for directly coupling said gear set output member to said engine output member, and a second selectably engageable friction device for directly coupling said gear set output member to said rotor, wherein said electric machine is effective as an electric brake reaction element to control torque transfer between said engine output member and said gear set output member, the method comprising:

detecting a predetermined set of vehicle drivetrain operating parameters;

controlling a torque influencing electric machine parameter to apply an amount of generator torque to the rotor as a function of said predetermined set of vehicle operating parameters thereby converging respective speeds of the rotor and the gear set output member;

when the speeds of the rotor and the gear set output member attain a predetermined speed differential relationship, controlling the rotor speed to the gear set output member speed;

engaging said first and second friction devices while controlling the rotor speed to the gear set output member speed.

11. A method of launching a vehicle from a substantially static condition as set forth in claim 10 wherein said step of engaging said first and second friction devices while controlling the rotor speed is effectuated by fully engaging said second friction device and progressively engaging said first friction device from an initial engagement pressure to a final engagement pressure, said initial and final engagement pressures being determined as a function of a predetermined measure of engine torque.

12. A method of launching a vehicle from a substantially static condition, said vehicle having a drivetrain comprising an internal combustion engine including an engine output member, a electric machine including a rotor, and a gear set operatively coupling said internal combustion engine output, said rotor and a gear set output member of said gear set, said gear set output member being operatively coupled to at least one drive wheel for propelling the vehicle, a first selectably engageable friction device for directly coupling said gear set output member to said engine output member, and a second selectably engageable friction device for directly coupling said gear set output member to said rotor, wherein said electric machine is effective as an electric brake reaction element to control torque transfer between said engine output member and said gear set output member, the method comprising:

detecting a predetermined set of vehicle drivetrain operating parameters;

performing an open loop control of a torque influencing electric machine parameter to apply an amount of generator torque to the rotor as a function of said predetermined set of vehicle operating parameters thereby converging respective speeds of the rotor and the gear set output member;

when the speeds of the rotor and the gear set output member attain a predetermined speed differential relationship, performing a closed loop control of the rotor speed to the gear set output member speed;

when the vehicle speed exceeds a predetermined threshold, fully engaging said second friction device and progressively engaging said first friction device from an initial engagement pressure to a final engagement pressure, said initial and final engagement pressures being determined as a function of a predetermined measure of engine torque.