Transmitting state switching control apparatus for hybrid vehicle

• US 20070227790A1
• Filed: 03/27/2007
• Published: 10/04/2007
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tanishima, Kaori
• Granted Patent: US 7,878,281 B2
• Time in Patent Office: Days
• US Class Current: 180/65.245
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• 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 2240/507 Operating parameters
• 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: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• 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 20/30 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 2510/0208 Clutch engagement state, e.g. engaged or disengaged
• CPC Class Codes: B60W 2510/0241 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60W 30/182 Selecting between different operative modes, e.g. comfort and performance modes
• CPC Class Codes: Y02T 10/40 : Engine management systems
• 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

Abstract

A control apparatus for a hybrid vehicle for controlling and limiting the transmission of power from an engine to the driving wheels during start-up of the engine to produce a hybrid running mode where the vehicle is powered by both the engine and a motor-generator.

Claims

1. An apparatus for controlling a hybrid vehicle having an engine, a motor-generator, and a clutch disposed between the engine and the motor and configured to vary a transmitted torque capacity, comprising:

a transmission disposed between the motor-generator and at least one driving wheel having at least two power transmitting paths through the selective engagement of at least one of a plurality of frictional engagement elements; and

a controller operable to transition the vehicle from an electric running mode to a hybrid running mode and wherein the controller is configured to selectively permit a slip state where at least one of the frictional engagement elements is allowed to slip during transition to the hybrid running mode from the electric running mode so as to control the driving force transmitted to the at least one driving wheel.

2. The apparatus of claim 1 wherein the slip state of the at least one frictional engagement element relates either before or after a shift is set to the transmitted torque capacity corresponding to a driving force required by the vehicle.

3. The apparatus of claim 2 wherein a starting of the engine and a shift of the transmission are performed at the same time after a progression of the engagement of the clutch during the electric running mode of the vehicle.

4. The apparatus of claim 1 wherein the slip state of the selected at least one of the frictional engagement elements is conditioned on a requested shift of the transmission in response to a requested driving force of the hybrid vehicle.

5. The apparatus of claim 4, wherein the selected at least one of the frictional engagement element permitted to slip is switched during an engine starting process during the start-up of the hybrid running mode.

6. The apparatus of claim 4 wherein the requested transmission shift is a downshift.

7. The apparatus of claim 5 wherein the switching of the frictional engagement element during the engine starting process first brings the frictional engagement elements engaged before and after the shift, to the slip state, and then switches the frictional engagement element disengaged after the shift, to the slip state.

8. The apparatus of claim 5 wherein the switching of the frictional engagement element during the engine starting process first brings the frictional engagement element engaged before the shift, and disengaged after the shift, to the slip state, and then switches the frictional engagement element newly engaged after the shift, to the slip state.

9. The apparatus of claim 5 wherein the switching of the frictional engagement element during the engine starting process first brings the frictional engagement element engaged after the shift, to the slip state, and then switches the frictional engagement element disengaged after the shift, to the slip state.

10. The apparatus of claim 7 wherein the switching to the slip state is performed from a time that the request of the shift arises to a time that the frictional engagement element engaged after the shift is engaged.

11. The apparatus of claim 1 wherein the slip state is conditioned on the transmitted torque capacity, the transmitted torque capacity is held substantially continuous during the start-up of the hybrid running mode even when the requested driving force by the vehicle is varied during the start-up of the hybrid running mode.

12. The apparatus of claim 1 wherein the frictional engagement elements are positioned in the transmission.

13. The apparatus of claim 1 wherein the frictional engagement elements comprise a second clutch.

14. The apparatus of claim 1 wherein the frictional engagement element on a disengagement side is brought to a slip state and then the frictional engagement element on an engagement side is brought to the slip state.

15. A hybrid vehicle, comprising:

an engine;

a motor-generator;

a clutch disposed between the engine and the motor-generator configured to vary a transmitted torque capacity;

a transmission disposed between the motor-generator and at least one driving wheel having at least two power transmitting paths through selected engagement of a plurality of frictional engagement elements; and

a controller operable to transition the vehicle from an electric running mode to a hybrid running mode and wherein the controller is configured to selectively permit a slip state where at least one of the frictional engagement elements is allowed to slip during transition to the hybrid running mode from the electric running mode so as to control the driving force transmitted to the at least one driving wheel.

16. The vehicle of claim 15 wherein the slip state of the frictional engagement element relates either before or after a shift is set to the transmitted torque capacity corresponding to a driving force required by the vehicle.

17. The vehicle apparatus of claim 15 wherein the slip state is conditioned on the transmitted torque capacity, the transmitted torque capacity is held substantially continuous during a start-up of the hybrid running mode even when the requested driving force by the vehicle is varied during the start-up of the hybrid running mode.

18. A method for controlling a hybrid vehicle having an engine, a motor-generator, a clutch disposed between the engine and the motor and configured to vary a transmitted torque capacity, a transmission disposed between the motor-generator and at least one driving wheel, and a plurality of frictional engagement elements positioned between the motor-generator and the at least one driving wheel, the method comprising:

transitioning the vehicle from an electric running mode to a hybrid running mode;

allowing at least one of the plurality of frictional engagement elements to slip during transition to the hybrid running mode from the electric running mode so as to control the transmission of power from the engine to the at least one driving wheel during start up of the engine.

19. The method of claim 18, further comprising:

holding the transmitted torque capacity substantially constant during the start-up of the hybrid running mode even when the requested driving force by the vehicle is varied during the start-up of the hybrid running mode.

20. The method of claim 18, further comprising:

switching the frictional engagement elements that are permitted to slip during start-up of the hybrid running mode.