Vehicle attitude control device

• US 20060169522A1
• Filed: 07/08/2005
• Published: 08/03/2006
• Est. Priority Date: 07/14/2004
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.)
• Inventors: Katayama, Yoshio
• Granted Patent: US 7,647,150 B2
• Time in Patent Office: Days
• US Class Current: 180/421
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement

Abstract

A vehicle attitude control device derives a stability factor during turning of a vehicle based on the behavior of the vehicle to take the derivation result as an estimated stability factor (step 112), compares the estimated stability factor with a reference stability factor (steps 114 and 116), varies an attitude control necessary-or-not judgment sensitivity based on the comparison result (steps 118, 130 and 134), and executes the attitude control for the vehicle (step 126).

Claims

1. A vehicle attitude control device for executing an attitude control for a vehicle based on a stability factor which represents a steering property of the vehicle, the vehicle attitude control device comprising:

estimated stability factor derivation means for deriving a stability factor during turning of the vehicle based on the behavior of the vehicle to take the derivation result as an estimated stability factor;

comparison means for comparing the estimated stability factor derived by the estimated stability factor derivation means with a reference stability factor set in advance; and

attitude control means for executing the attitude control for the vehicle after varying an attitude control necessary-or-not judgment sensitivity in dependence on a comparison result obtained by the comparison means.

2. The vehicle attitude control device as set forth in claim 1, wherein when the estimated stability factor is smaller than the reference stability factor, the attitude control means executes the attitude control for the vehicle after varying the attitude control necessary-or-not judgment sensitivity for an understeer control.

3. The vehicle attitude control device as set forth in claim 1, wherein when the estimated stability factor is larger than the reference stability factor, the attitude control means executes the attitude control for the vehicle after varying the attitude control necessary-or-not judgment sensitivity for an oversteer control.

4. The vehicle attitude control device as set forth in claim 1, wherein the attitude control means compares a yaw rate deviation derived based on the estimated stability factor with a control intervention threshold value and executes the attitude control for the vehicle in dependence on the result of such comparison, and wherein the attitude control means varies the attitude control necessary-or-not judgment sensitivity by varying the control intervention threshold value based on the result of the comparison between the estimated stability factor and the reference stability factor.

5. The vehicle attitude control device as set forth in claim 1, wherein the attitude control means varies the attitude control necessary-or-not judgment sensitivity by compensating the estimated stability factor based on the result of the comparison between the estimated stability factor and the reference stability factor.

6. The vehicle attitude control device as set forth in claim 1, wherein the reference stability factor is a value set arbitrarily within a stability factor range peculiar to the vehicle.

7. The vehicle attitude control device as set forth in claim 1, wherein the attitude control means executes the attitude control for the vehicle after lowering the attitude control necessary-or-not judgment sensitivity before starting the derivation of the estimated stability factor by the estimated stability factor derivation means.

8. The vehicle attitude control device as set forth in claim 1, wherein the attitude control means controls the attitude of the vehicle by controlling brake force applied to wheels or/and by controlling an output torque of an engine.

9. A vehicle attitude control device comprising:

vehicle body speed detection means for detecting a vehicle body speed;

steering angle detection means for detecting a steering angle of the vehicle;

actual yaw rate detection means for detecting a yaw rate actually exerted on the vehicle;

target yaw rate calculation means for calculating a target yaw rate of the vehicle based on a stability factor representing the steering property of the vehicle; and

yaw rate deviation calculation means for calculating a yaw rate deviation by executing a subtraction between the actual yaw rate detected by the actual yaw rate detection means and the target yaw rate calculated by the target yaw rate calculation means;

wherein a comparison between the yaw rate deviation calculated by the yaw rate deviation calculation means and a control intervention threshold value is made to execute an attitude control for the vehicle based on the comparison result, and wherein the vehicle attitude control device further comprises;

estimated stability factor derivation means for deriving a stability factor during turning of the vehicle based on the behavior of the vehicle to take the derivation result as an estimated stability factor;

comparison means for comparing the estimated stability factor derived by the estimated stability factor derivation means with a reference stability factor; and

attitude control means for executing the attitude control for the vehicle after varying an attitude control necessary-or-not judgment sensitivity based on a comparison result obtained by the comparison means.