Vehicle behavior control device

• US 8,019,518 B2
• Filed: 07/30/2008
• Issued: 09/13/2011
• Est. Priority Date: 08/01/2007
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Yamazaki, Yoshinobu
• Primary Examiner(s): Trammell; James
• Assistant Examiner(s): Shafi; Muhammad
• Application Number:
  US12/219,928
• Publication Number:
  US 20090037053A1
• Time in Patent Office: 1,140 Days
• Field of Search: 701/41, 701/42, 701/51, 701/52, 701/61, 701/60, 701/71, 701/78, 701/83, 701/87, 701/89, 701/1, 701/53, 701/91, 701/69, 180/6.2, 180/6.3, 180/118, 180/119, 180/197, 180/204, 180/234, 180/242, 180/243, 180/245, 180/246, 180/201, 180/15, 180/345, 116/36, 315/80
• US Class Current: 701/51
• CPC Class Codes: B60K 23/04 for differential gearing
• CPC Class Codes: B60W 10/14 Central differentials for dividing torque between front and rear axles
• CPC Class Codes: B60W 10/16 Axle differentials, e.g. for dividing torque between left and right wheels
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/20 Sideslip angle
• CPC Class Codes: B60W 2540/18 Steering angle

Abstract

A basic-additional-yaw-moment setting section sets a basic additional yaw moment and determines the polarity of the basic additional yaw moment on the basis of a steering-wheel angle, a yaw rate, and a vehicle speed. A left-right driving-force distribution controller sets the driving-force distribution with respect to left and right driving wheels on the basis of the basic additional yaw moment and the polarity of the basic additional yaw moment, and adjusts the driving-force distribution when a vehicle drive control operation signal is output from a vehicle drive control unit. Specifically, the left-right driving-force distribution control section adjusts the driving-force distribution such that the polarity of the basic additional yaw moment is in the same direction as that of a yaw moment applied by the vehicle drive control unit.

Claims

1. A vehicle behavior control device comprising:

steering-wheel-angle detecting means configured to detect a steering-wheel angle;

yaw-rate detecting means configured to detect a yaw rate;

vehicle-speed calculating means configured to determine a vehicle speed;

sideslip prevention controlling means configured to prevent a sideslip by controlling a vehicle; and

driving-force-distribution controlling means configured to control driving-force distribution with respect to at least left and right driving wheels,

wherein the driving-force-distribution controlling means includes

additional-yaw-moment setting means configured to set an additional yaw moment to be added to the vehicle and to determine a polarity of the additional yaw moment on the basis of the steering-wheel angle, the yaw rate, and the vehicle speed, and

left-right driving-force distribution controlling means configured to set the driving-force distribution with respect to the left and right driving wheels on the basis of the additional yaw moment and the polarity of the additional yaw moment set and determined by the additional-yaw-moment setting means, and to adjust the driving-force distribution when an operation signal for sideslip prevention is output from the sideslip prevention controlling means, the driving-force distribution being adjusted such that the polarity of the additional yaw moment is in the same direction as that of a yaw moment applied by the sideslip prevention controlling means.

2. The vehicle behavior control device according to claim 1, wherein a power transmission system between front and rear wheels is provided with a differential device and a limited-slip differential device that limits a differential of the differential device,

wherein the driving-force-distribution controlling means further includes front-rear driving-force distribution controlling means configured to activate the limited-slip differential device in accordance with a running condition of the vehicle so as to set driving-force distribution with respect to the front and rear wheels, and

wherein when the operation signal for sideslip prevention is output from the sideslip prevention controlling means and throttle-opening detecting means detects that a throttle opening of a throttle valve is in a completely closed state, the driving-force-distribution controlling means cancels limitation of the differential by the limited-slip differential device.

3. The vehicle behavior control device according to claim 2, wherein the driving-force-distribution controlling means activates the limited-slip differential device in accordance with the running condition of the vehicle when the operation signal for sideslip prevention is output from the sideslip prevention controlling means, when the vehicle is in an oversteer condition, and when the throttle-opening detecting means detects that the throttle opening of the throttle valve is in an open state.

4. The vehicle behavior control device according to claim 1, wherein the steering-wheel-angle detecting means includes lateral-acceleration detecting means configured to detect a lateral acceleration, the steering-wheel-angle detecting means determining the steering-wheel angle on the basis of the lateral acceleration detected by the lateral-acceleration detecting means.