Hybrid vehicle drive system including controllable device between engine and electric motor and vehicle drive wheels, and apparatus for controlling the device depending upon selected operation mode of the system

• US 6,081,042 A
• Filed: 03/20/1997
• Issued: 06/27/2000
• Est. Priority Date: 03/22/1996
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tabata, Atsushi, Ibaraki, Ryuji, Taga, Yutaka, Hata, Hiroshi, Mikami, Tsuyoshi
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/821,312
• Time in Patent Office: 1,195 Days
• Field of Search: 290/11, 290/32, 290/45, 310/266, 180/65.2, 475/5
• US Class Current: 290/45
• CPC Class Codes: B60K 2006/4833 Step up or reduction gearing driving generator, e.g. to operate generator in most efficient speed range
• 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: 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 10/26 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: F02D 2200/1006 Engine torque losses, e.g. friction or pumping losses or losses caused by external loads of accessories
• CPC Class Codes: F16H 2061/0087 Adaptive control, e.g. the control parameters adapted by learning
• CPC Class Codes: F16H 59/78 Temperature
• CPC Class Codes: F16H 61/0021 Generation or control of line pressure
• CPC Class Codes: F16H 61/0206 Layout of electro-hydraulic control circuits, e.g. arrangement of valves for control of actuators selecting and moving final output members, e.g. shift forks F16H61/2807
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/91 Orbital, e.g. planetary gears
• 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

Abstract

A hybrid drive system for a motor vehicle, wherein a controllable device such as an automatic transmission or a center differential device is disposed between drive wheels of the vehicle and a drive power source consisting of an engine operated by combustion of a fuel, and an electric motor operated with an electric energy, and the engine and/or the electric motor is/are operated for driving the motor vehicle in different running modes. The controllable device is controlled by a control device on the basis of an input torque received by the controllable device. The control device is adapted to estimate the input torque of depending upon a currently selected one of the running modes, or effect learning control of the controllable device in different manners corresponding to the different running modes.

Claims

1. A hybrid drive system for a motor vehicle, comprising:

a drive power source consisting of an engine operated by combustion of a fuel, and an electric motor operated with an electric energy, at least one of said engine and said electric motor being operated for running the motor vehicle in a plurality of running modes;

a controllable device disposed between said drive power source and drive wheels of the motor vehicle; and

a control device for controlling said controllable device on the basis of an input torque received by said controllable device,

and wherein said control device comprises input torque estimating means for estimating said input torque of said controllable device depending upon a currently selected one of said plurality of running modes.

2. A hybrid drive system according to claim 1, wherein said controllable device comprises an automatic transmission having a plurality of operating positions having respective different speed ratios, said automatic transmission including a plurality of coupling devices which are selectively engaged and released for selectively establishing said plurality of operating positions, said control device controlling said coupling devices for at least one of shifting actions of said automatic transmission, on the basis of the input torque of said automatic transmission estimated by said input torque estimating means.

3. A hybrid drive system according to claim 2, wherein said coupling devices are hydraulically operated coupling devices, and said control device further comprises pressure control means for controlling a hydraulic pressure of at least one of two coupling devices of said hydraulically operated coupling devices on the basis of said input torque estimated by said input torque estimating means, one of said two coupling devices being engaged while the other of said two coupling devices being released, for shifting said automatic transmission from one of said operating positions to another.

4. A hybrid drive system according to claim 1, wherein said plurality of running modes include a motor drive mode in which the motor vehicle is driven by only said electric motor, and said input torque estimating means estimates said input torque on the basis of an output torque of said electric motor as compensated by an inertia of said electric motor.

5. A hybrid drive system according to claim 1, wherein said plurality of running modes include an engine drive mode in which the motor vehicle is driven by only said engine, and said input torque estimating means estimates said input torque on the basis of an output torque of said engine as compensated by an inertia and a torque loss of said engine.

6. A hybrid drive system according to claim 1, wherein said plurality of running modes include an engine·

motor drive mode in which the motor vehicle is driven by both of said engine and said electric motor, and said input torque estimating means estimates said input torque on the basis of an output torque of said engine as compensated by an inertia and a torque loss of said engine, and an output torque of said electric motor as compensated by an inertia of said electric motor.

7. A hybrid drive system according to claim 1, further comprising an electric energy storage device for storing the electric energy with which said electric motor is operated, and wherein said plurality of running modes include an engine drive and charging mode in which the motor vehicle is driven by said engine while said electric motor is operated as an electric generator for charging said electric energy storage device, said input torque estimating means estimating said input torque on the basis of an output torque of said engine as compensated by an inertia and a torque loss of said engine, and a regenerative braking torque of said electric motor as compensated by an inertia of said electric motor.

8. A hybrid drive system according to claim 1, wherein said controllable device comprises an automatic transmission, and said control device further comprises learning control means for effecting a learning control of at least one controllable variable of said automatic transmission, which at least one controllable variable influences a shifting action of said automatic transmission, said learning control means effecting said learning control in different manners corresponding to said plurality of running modes of the motor vehicle.

9. A hybrid drive system for a motor vehicle, comprising:

a drive power source consisting of an engine operated by combustion of a fuel, and an electric motor operated with an electric energy, at least one of said engine and said electric motor being operated for driving the motor vehicle in a plurality of running modes;

an automatic transmission disposed between said drive power source and drive wheels of the motor vehicle; and

a shift control device for controlling at least one controllable variable of said automatic transmission, which at least one controllable variable influences a shifting action of said automatic transmission,

and wherein said shift control device comprises learning control means for effecting a learning control of said at least one controllable variable in different manners corresponding to said plurality of running modes of the motor vehicle.

10. A hybrid drive system according to claim 9, wherein said automatic transmission has a plurality of operating positions having respective different speed ratios, said automatic transmission including a plurality of coupling devices which are selectively engaged and released for selectively establishing said plurality of operating positions, said shift control device controlling said coupling devices for at least one of shifting actions of said automatic transmission.

11. A hybrid drive system according to claim 10, wherein said coupling devices are hydraulically operated coupling devices, and said learning control means includes pressure control means for effecting the learning control of a hydraulic pressure of at least one of two coupling devices of said hydraulically operated coupling devices in different manners corresponding to said plurality of running modes of the motor vehicle, said shift control device controlling said two coupling device such that one of said two coupling devices is engaged while the other of said two coupling devices is released, for shifting said automatic transmission from one of said operating positions to another.

12. A hybrid drive system according to claim 11, wherein said learning control means has memory means for storing a plurality of data maps corresponding to said plurality of running modes of the motor vehicle, each of said data maps representing a relationship between an operating parameter of said automatic transmission and a compensating value of said hydraulic pressure of each of said at least one of said two coupling devices, said learning control means determining said compensating value on the basis of said operating parameter and according to one of said data maps which corresponds to a currently selected one of said plurality of running modes.

13. A hybrid drive system according to claim 12, wherein said learning control means updates each of said data maps depending upon a condition in which said automatic transmission has been shifted from one of said plurality operating positions to another in said currently selected one of said plurality of running modes.

14. A hybrid drive system according to claim 12, wherein said shift control device further comprises input torque estimating means for estimating said input torque of said automatic transmission, as said operating parameter, depending upon said currently selected one of said plurality of running modes, said learning control means determining said compensating value of said hydraulic pressure on the basis of said input torque estimated by said input torque estimating means and according to said one of said data maps.

15. A hybrid drive system according to claim 9, wherein said shift control means further comprises learning control inhibiting means for inhibiting said learning control means from operating to effect said learning control of said at least one controllable variable, in at least one predetermined running condition of the motor vehicle including at least one of:

a condition that the currently selected running mode of the motor vehicle has changed from one of said plurality of running modes to another during said shifting action of said automatic transmission; and

a condition that a predetermined time has not passed after the currently selected running mode has been selected.

16. A hybrid drive system for a motor vehicle having front and rear drive wheels, comprising:

a drive power source consisting of an engine operated by combustion of a fuel, and an electric motor operated with an electric energy, at least one of said engine and said electric motor being operated for driving the motor vehicle in a plurality of running modes;

a torque distributing mechanism disposed between said drive power source and said drive wheels of the motor vehicle, for distributing a drive torque produced by said drive power source to said front drive wheels and said rear drive wheels at a controllable distribution ratio;

torque distribution ratio changing means for controlling said torque distributing mechanism to change said distribution ratio of said drive torque; and

learning control means for effecting a learning control of a controllable variable of said torque distributing mechanism which influences said distribution ratio, when said distribution ratio is changed by said torque distribution ratio changing means,

and wherein said learning control means effects said learning control of said controllable variable in different manners corresponding to said plurality of running modes of the motor vehicle.

17. A hybrid drive system according to claim 16, further comprising learning control inhibiting means for inhibiting an operation of said learning control means from operating to effect said learning control of said controllable variable, in at least one predetermined running condition of the motor vehicle.

18. A hybrid drive system according to claim 17, wherein said at least one predetermined running condition includes at least one of:

a condition that a predetermined time has not passed after the currently selected running mode has been selected;

a condition that a temperature of a working fluid for operating said torque distributing mechanism is lower than a predetermined lower limit; and

a condition that a temperature of a coolant water for cooling said engine is lower than a predetermined lower limit.

19. A hybrid drive system according to claim 16, wherein said torque distributing mechanism comprises a center differential device including a hydraulically operated differential limiting clutch whose hydraulic pressure is changed by said torque distribution ratio changing means.

20. A hybrid drive system according to claim 19, wherein said learning control means comprises pressure control means for effecting learning control of said hydraulic pressure of said differential limiting clutch as said variable of said torque distributing mechanism, in different manners corresponding to said plurality of running modes of the motor vehicle.

21. A hybrid drive system according to claim 20, wherein said learning control means has memory means for storing a plurality of data maps corresponding to said plurality of running modes of the motor vehicle, each of said data maps representing a relationship between an operating parameter of said center differential device and a compensating value of said hydraulic pressure of said differential limiting clutch, said learning control means determining said compensating value on the basis of said operating parameter and according to one of said data maps which corresponds to a currently selected one of said plurality of running modes.

22. A hybrid drive system according to claim 21, wherein said operating parameter of said center differential device is an input torque received by said center differential device.

23. A hybrid drive system according to claim 21, wherein said learning control means updates each of said data maps depending upon a condition in which said distribution ratio is changed by changing said hydraulic pressure of said differential limiting clutch by said pressure control means, in one of said running modes which corresponds to said each data map.