Hybrid vehicle drive control system

• US 7,975,791 B2
• Filed: 11/08/2006
• Issued: 07/12/2011
• Est. Priority Date: 11/09/2005
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Nakamura, Kiminori, Nozaki, Yuji
• Primary Examiner(s): Phan; Hau V
• Assistant Examiner(s): Chibogu; Chiedu A
• Application Number:
  US11/594,251
• Publication Number:
  US 20070114082A1
• Time in Patent Office: 1,707 Days
• Field of Search: 903/917, 477/2, 477/5, 477/6
• US Class Current: 180/65.6
• 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 2240/423 Torque
• 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: B60L 50/51 characterised by AC-motors
• 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 10/11 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• 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 2710/025 Clutch slip, i.e. difference between input and output speeds
• 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 hybrid vehicle drive control system has a first clutch interposed between an engine and a motor/generator, a transmission including several gear position clutches arranged between the motor/generator and a drive wheel, and a controller. The controller selectively starts the engine using torque from the first clutch during a drive mode change from an electric drive mode to a hybrid drive mode. When an engine start command and a gear shifting operation occur during a drive mode change, the controller selects the gear position clutch that is a common engaged clutch from among the engaged gear position clutches constituting the vehicle running gears occurring from immediately before starting the engine until immediately after starting the engine as a second clutch to be controlled. Then, the controller executes a slip control of the second clutch when the first clutch is being connected to start the engine during the drive mode change.

Claims

1. A hybrid vehicle drive control system comprising:

an engine;

a motor/generator;

a first clutch arranged between the engine and the motor/generator;

a transmission including a plurality of gear position clutches arranged between the motor/generator and at least one drive wheel of a hybrid vehicle, with the gear position clutches being selectively engaged to obtain one of a plurality of vehicle running gears, the plurality of gear position clutches of the transmission having a first common engaged clutch that remains engaged throughout a first shifting mode and a second common engaged clutch that remains engaged throughout a second shifting mode, the first and second shifting modes being different gear shifts from one of the vehicle running gears to a different one of the vehicle running gears; and

a controller that selectively starts the engine by using torque transmitted from the first clutch during a mode change from an electric drive mode in which the first clutch is released to a hybrid drive mode in which the first clutch is engaged in response to an engine start command being issued while the hybrid vehicle is running in the electric drive mode with the motor/generator being used as a power source for driving the drive wheel of the hybrid vehicle,

the controller selecting a second clutch that is detected as being a common engaged clutch, with the second clutch being the first common engaged clutch in response to the controller performing the first shifting mode and with the second clutch being the second common engaged clutch in response to the controller performing the second shifting mode during a period lasting from immediately before starting the engine until immediately after starting the engine in response to the engine start command being issued to start the engine and the gear shifting operation occurring during the mode change from the electric drive mode to the hybrid drive mode, and executing a slip control of the second clutch in response to the first clutch being connected to start the engine during the mode change from the electric drive mode to the hybrid drive mode.

2. The hybrid vehicle drive control system as set forth in claim 1, wherein

the controller selects the second clutch to be slip controlled by detecting which of the gear position clutches that are engaged to constitute the vehicle running gears which are engaged immediately prior to starting the engine in response to the engine start command having a maximum torque transfer capacity, upon detecting that no gear shifting operation is occurring during the mode change from the electric drive mode to the hybrid drive mode.

3. The hybrid vehicle drive control system as set forth in claim 1, wherein

the controller selects the second clutch to be slip controlled by detecting which of the gear position clutches has a maximum torque transfer capacity from among a plurality of common engaged clutches that are engaged to constitute the vehicle running gears which are engaged during the period lasting from immediately before starting the engine until immediately after starting the engine in response to the engine start command being issued to start the engine and the gear shifting operation occurring during the mode change from the electric drive mode to the hybrid drive mode.

4. The hybrid vehicle drive control system as set forth in claim 1, wherein

the controller reduces a torque transfer capacity of the second clutch to be slip controlled in response to a completely engaged clutch from among the gear position clutches being selected as the second clutch.

5. The hybrid vehicle drive control system as set forth in claim 2, wherein

the controller selects the second clutch to be slip controlled by detecting which of the gear position clutches has a maximum torque transfer capacity from among a plurality of common engaged clutches that are engaged to constitute the vehicle running gears which are engaged during the period lasting from immediately before starting the engine until immediately after starting the engine when the engine start command is issued to start the engine and the gear shifting operation is occurring during the mode change from the electric drive mode to the hybrid drive mode.

6. The hybrid vehicle drive control system as set forth in claim 2, wherein

the controller reduces a torque transfer capacity of the second clutch to be slip controlled in response to a completely engaged clutch from among the gear position clutches being selected as the second clutch.

7. The hybrid vehicle drive control system as set forth in claim 3, wherein

the controller reduces a torque transfer capacity of the second clutch to be slip controlled in response to a completely engaged clutch from among the gear position clutches being selected as the second clutch.

8. The hybrid vehicle drive control system as set forth in claim 5, wherein

the controller reduces a torque transfer capacity of the second clutch to be slip controlled in response to a completely engaged clutch from among the gear position clutches being selected as the second clutch.

9. A hybrid vehicle drive control system comprising:

first power supply means for supplying a first source of power in a hybrid drive mode;

second power supply means for supplying a second source of power at least in an electric drive mode;

first power transfer means for selectively changing a torque transfer capacity between the first and second power supply means;

vehicle running gear changing means for selectively changing a gear position among a plurality of vehicle running gear of a hybrid vehicle between the first and second power supply means and at least one drive wheel of a hybrid vehicle, the vehicle running gear changing means including a plurality of frictional engaging means for selectively attaining the vehicle running gears, the plurality of frictional engaging means having a first common engaged clutch that remains engaged throughout a first shifting mode and a second common engaged clutch that remains engaged throughout a second shifting mode, the first and second shifting modes being different gear shifts from one of the vehicle running gears to a different one of the vehicle running gears; and

control means for selectively starting the first power supply means by using torque transmitted from the first power transfer means during a mode change from the electric drive mode to a hybrid drive mode when a first power supply start command is issued while the hybrid vehicle is running in the electric drive mode with the second power supply being used as a power source for driving the drive wheel of the hybrid vehicle,

the control means further including functions of selecting one of the frictional engaging means that is detected as being a common engaged clutch, with the one of the frictional engaging means being the first common engaged clutch in response to the control means performing the first shifting mode and with the one of the frictional engaging means being the second common engaged clutch in response to the control means performing the second shifting mode during an engine starting process when the first power supply start command is issued to start the first power supply means and the gear shifting operation is occurring during the mode change from the electric drive mode to the hybrid drive mode, and executing a slip control of the frictional engaging means that was detected as being the common engaged clutch when the first power transfer means is being connected to start the first power supply means during the mode change from the electric drive mode to the hybrid drive mode.

10. A hybrid vehicle drive control method comprising:

selectively operating a first clutch arranged between an engine and a motor/generator;

selectively operating gear position clutches of a transmission arranged between a motor/generator and at least one drive wheel of a hybrid vehicle, with the gear position clutches being selectively engaged to obtain one of a plurality of vehicle running gears, the gear position clutches of the transmission having a first common engaged clutch that remains engaged throughout a first shifting mode and a second common engaged clutch that remains engaged throughout a second shifting mode, the first and second shifting modes being different gear shifts from one of the vehicle running gears to a different one of the vehicle running gears;

selectively starting the engine by using torque transmitted from the first clutch during a mode change from an electric drive mode in which the first clutch is released to a hybrid drive mode in which the first clutch is engaged when an engine start command is issued while the hybrid vehicle is running in the electric drive mode with the motor/generator being used as a power source for driving the drive wheel of the hybrid vehicle;

selecting a second clutch that is detected as being a common engaged clutch, with the second clutch being the first common engaged clutch in response to the first shifting mode and with the second clutch being the second common engaged clutch in response to the second shifting mode during a period lasting from immediately before starting the engine until immediately after starting the engine when the engine start command is issued to start the engine and the gear shifting operation is occurring during the mode change from the electric drive mode to the hybrid drive mode; and

executing a slip control of the second clutch when the first clutch is being connected to start the engine during the mode change from the electric drive mode to the hybrid drive mode.