Control device for hybrid four-wheel-drive vehicle and hybrid four-wheel-drive vehicle

• US 7,114,589 B2
• Filed: 08/10/2004
• Issued: 10/03/2006
• Est. Priority Date: 03/24/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kowatari, Takehiko, Yamamoto, Tatsuyuki
• Primary Examiner(s): Hurley, Kevin
• Application Number:
  US10/914,423
• Publication Number:
  US 20050211489A1
• Time in Patent Office: 784 Days
• Field of Search: 180/242, 180/243, 180/197, 701/89
• US Class Current: 180/243
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 2240/423 Torque
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2520/263 Slip values between front and rear axle
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A control device controls a hybrid-four-wheel-driven vehicle wherein one of the front-wheel pair and the rear-wheel pair is an engine-driven-wheel pair which is driven by an engine, and the other pair is an electric-motor-driven-wheel pair which is driven by an electric motor. In the event of slipping of the engine-driven wheels, the system increases the engine output so as to increase the driving force of the electric-motor-driven wheels for increasing the total driving force made up of the engine-driven-wheel driving force and the electric-motor-driven-wheel driving force, thereby improving acceleration performance, unlike conventional techniques. This provides a control device for suppressing deterioration in acceleration performance of the vehicle in a case of slipping of engine-driven wheels during acceleration.

Claims

1. A control device for controlling a hybrid-four-wheel-driven vehicle wherein one of the front-wheel pair and the rear-wheel pair is an engine-driven-wheel pair which is driven by an engine, and the other pair is an electric-motor-driven-wheel pair which is driven by an electric motor connected to a generator driven by said engine, said control device comprising:

slipping detecting means for detecting slipping of said engine-driven wheels; and

output control means for increasing the output of said engine corresponding to the increased output of said electric motor,

wherein said slipping detecting means detects slipping in the event that the speed of said engine-driven wheels exceeds the driving speed of the vehicle.

2. A control device for controlling a hybrid-four-wheel-driven vehicle wherein one of the front-wheel pair and the rear-wheel pair is an engine-driven-wheel pair which is driven by an engine, and the other pair is an electric-motor-driven-wheel pair which is driven by an electric motor connected to a generator driven by said engine, said control device comprising:

slipping detecting means for detecting slipping of said engine-driven wheels; and

output control means for increasing the output of said engine corresponding to the increased output of said electric motor,

wherein said slipping detecting means detects slipping in the event that the slippage, which is the difference in rotational speed between said engine-driven wheels and said electric-motor-driven wheels, divided by the driving speed of the vehicle, is equal to or greater than a predetermined value.

3. A control device for controlling a hybrid-four-wheel-driven vehicle wherein one of the front-wheel pair and the rear-wheel pair is an engine-driven-wheel pair which is driven by an engine, and the other pair is an electric-motor-driven-wheel pair which is driven by an electric motor connected to a generator driven by said engine, said control device comprising:

slipping detecting means for detecting slipping of said engine-driven wheels; and

output control means for increasing the output of said engine corresponding to the increased output of said electric motor,

wherein said output control means further comprises;

means for computing the present electric-motor output based upon an input current and a field-coil current of said electric motor;

means for computing target acceleration driving force corresponding to an input acceleration request;

means for obtaining target electric-motor output based upon said present electric-motor output and said target acceleration driving force;

means for obtaining target engine output required for achieving said target electric-motor output; and

means for controlling output of said engine and output of said electric motor according to said target engine output and said target electric-motor output.

4. A control device for controlling a hybrid-four-wheel-driven vehicle wherein one of the front-wheel pair and the rear-wheel pair is an engine-driven-wheel pair which is driven by an engine, and the other pair is an electric-motor-driven-wheel pair which is driven by an electric motor connected to a generator driven by said engine, said control device comprising:

slipping detecting means for detecting slipping of said engine-driven wheels; and

output control means for increasing the output of said engine corresponding to the increased output of said electric motor,

wherein said output control means further comprises;

effective-driving-force history computation means for obtaining history data of the effective driving force of said electric-motor driving wheels corresponding to the last slippage data for a predetermined past period; and

maximum-effective-driving-force computation means for computing the maximum value of the effective driving force of said electric-motor-driven wheels based upon said history data, wherein the output of said electric motor is increased in a range determined by the maximum value of the effective driving force of said electric-motor-driven wheels.