Hybrid vehicle and method of controlling the vehicle

• US 7,381,146 B2
• Filed: 08/12/2003
• Issued: 06/03/2008
• Est. Priority Date: 08/12/2003
• Status: Active Grant

• Current Assignee: Nissan Diesel Motor Co., Ltd. (Isuzu Motors Limited)
• Original Assignee: Nissan Diesel Motor Co., Ltd. (Isuzu Motors Limited)
• Inventors: Suzuki, Yuji, Nishina, Mitsuhiro, Gouda, Hideaki
• Primary Examiner(s): Estremsky; Sherry
• Assistant Examiner(s): YOUNG, EDWIN
• Application Number:
  US10/566,442
• Publication Number:
  US 20060199696A1
• Time in Patent Office: 1,757 Days
• Field of Search: 903/941
• US Class Current: 477/3
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• 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: Y10S 903/905 : Combustion engine

Abstract

A controller (10) of a hybrid vehicle determines an engine torque at a point on an engine torque high efficiency line at the current engine rotation speed as a target engine torque, and determines the current engine torque from the current engine rotation speed and current accelerator depression amount. Then, when the gear position of a transmission (2) is neutral, the vehicle is stationary and a storage device (9) requires charging, the controller (10) sets the difference between the target engine torque and the current engine torque as a target power generation torque of a motor generator (4), sets a transitional time period corresponding to the target power generation torque, and performs control over the transitional time period to raise the power generation torque of the motor generator gradually to the target power generation torque.

Claims

1. A hybrid vehicle comprising an engine (1), a transmission (2) which changes a speed of a rotation of an input shaft and transmits the rotation to an output shaft, a motor generator (4), a power transmission mechanism (5) which connects a rotary shaft of the motor generator (4) and the input shaft of the transmission (2), a storage device (9) which is connected to the motor generator (4), and a controller (10),

characterized in that the controller (10) sets an engine torque at a point on an engine torque high efficiency line at a current engine rotation speed as a target engine torque,

calculates a current engine torque from the current engine rotation speed and a current accelerator depression amount, and

when a gear position of the transmission (2) is neutral, the vehicle is stationary, and the storage device (9) requires charging, sets a difference between the target engine torque and the current engine torque as a target power generation torque of the motor generator (4), and controls the motor generator (4) such that a power generation torque of the motor generator (4) matches the target power generation torque.

2. The hybrid vehicle as defined in claim 1, characterized in that the controller (10) sets a transitional time period corresponding to the target power generation torque, and controls the motor generator (4) over the transitional time period to raise the power generation torque to the target powergeneration torque.

4. The hybrid vehicle as defined in claim 1, characterized in that the controller (10) halts an operation of the engine (1) when the gear position of the transmission (4) is neutral, the vehicle is stationary, and the storage device (9) does not require charging.

3. The hybrid vehicle as defined in 2, characterized in that the controller (10) halts an operation of the engine (1) when the gear position of the transmission (4) is neutral, the vehicle is stationary, and the storage device (9) does not require charging.

5. A control method for a hybrid vehicle comprising an engine (1), a transmission (2) which changes a speed of a rotation of an input shaft and transmits the rotation to an output shaft, a motor generator (4), a power transmission mechanism (5) which connects a rotary shaft of the motor generator (4) and the input shaft of the transmission (2), and a storage device (9) which is connected to the motor generator (4), characterized in that the control method comprises:

setting an engine torque at a point on an engine torque high efficiency line at a current engine rotation speed as a target engine torque,

calculating a current engine torque from the current engine rotation speed and a current accelerator depression amount, and

when a gear position of the transmission (2) is neutral, the vehicle is stationary, and the storage device (9) requires charging, setting a difference between the target engine torque and the current engine torque as a target power generation torque of the motor generator (4), and controlling the motor generator (4) such that a power generation torque of the motor generator (4) matches the target power generation torque.