Vehicle posture control apparatus

• US 20020087247A1
• Filed: 10/24/2001
• Published: 07/04/2002
• Est. Priority Date: 10/24/2000
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.), Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation, Sumitomo Electric Industries, Inc.
• Inventors: Tanaka, Hirohisa, Watanabe, Yoshihiro, Yasutake, Toshio, Nishioka, Jouji
• Granted Patent: US 6,584,397 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 2220/03 Driver counter-steering; Avoidance of conflicts with ESP control
• 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

Abstract

In a posture control apparatus controlling the posture of a vehicle in yawing direction by independently controlling brakes of the wheels, intervention of a first understeer control suppressing an understeering tendency is carried out when the understeering tendency of the vehicle is stronger than a preset reference value. Moreover, intervention of a second understeer control, in which the control amount is lower than in the first understeer control, is carried out when the actual yaw rate does not make a predetermined change with respect to a change of a steering wheel angle, thus improving the sense of stability and the controllability felt by the driver.

Claims

1. A vehicle posture control apparatus provided with a control means for controlling posture of the vehicle in yawing direction by independently controlling brakes of the vehicle'"'"'s wheels,

wherein the control means carries out intervention of a first understeer control suppressing an understeering tendency when the understeering tendency of the vehicle is stronger than a preset reference value;

and

wherein the control means carries out intervention of a second understeer control, in which the control amount is lower than in the first understeer control, when the actual yaw rate does not make a predetermined change with respect to a change of a steering wheel angle of the vehicle.

2. The vehicle posture control apparatus according to claim 1, wherein the second understeer control supplies a brake pressure whose upper limit is a predetermined brake pressure that is set to be lower than the maximum brake pressure that can be supplied in the first understeer control.

3. The vehicle posture control apparatus according to claim 1, wherein the control means carries out intervention of the second understeer control when the steering wheel is turned from an orientation in which the vehicle is moving straight forward and the actual yaw rate does not make a predetermined change with respect to the change of the steering wheel angle when turning the steering wheel.

4. The vehicle posture control apparatus according to claim 1, wherein, after intervention of the second understeer control, the control means stops the second understeer control when a deviation between the change rate of the steering wheel angle and the actual yaw rate has switched to a decreasing tendency.

5. The vehicle posture control apparatus according to claim 1, wherein the first understeer control controls the braking of a cornering inside rear wheel, and the second understeer control controls the braking of a cornering inside front wheel.

6. The vehicle posture control apparatus according to claim 1, wherein the control means prohibits the intervention of the second understeer control when the vehicle has an oversteering tendency that is stronger than a preset reference value.

7. The vehicle posture control apparatus according to claim 1, wherein the control means judges an understeering tendency of the vehicle with regard to the first understeer control based on a deviation between a target yaw rate set based on lateral acceleration of the vehicle and the actual yaw rate of the vehicle.