Vehicle systems control for improving stability

Abstract

Improved methods of controlling the stability of a vehicle are provided via the cooperative operation of vehicle stability control systems such as an Active Yaw Control system, Antilock Braking System, and Traction Control System. These methods use recognition of road surface information including the road friction coefficient (mu), wheel slippage, and yaw deviations. The methods then modify the settings of the active damping system and/or the distribution of drive torque, as necessary, to increase/reduce damping in the suspension and shift torque application at the wheels, thus preventing a significant shift of load in the vehicle and/or improving vehicle drivability and comfort. The adjustments of the active damping system or torque distribution temporarily override any characteristics that were pre-selected by the driver.

1 . A cooperative Active Damping System (ADS) method for providing vehicle stability comprising the steps of:
 providing a vehicle stability assist (VSA) system that determines yaw deviation from a desired condition, the system including a vehicle stability assist—Active Yaw Control electronic control unit (VSA-AYC ECU);   providing an Active Damping System (ADS) for adjusting the suspension stiffness on the vehicle, at least independently between the front and the rear of the vehicle;   shifting the front to back damping distribution between using the ADS in order to correct the yaw deviation.   
     
     
         2 . The method according to  claim 1 , further comprising the step of reducing yaw deviation via braking if sufficient yaw rate error reduction cannot be obtained via the shifting of suspension stiffness from front to back. 
     
     
         3 . The method according to  claim 1 , wherein the ADS includes electronically controlled, fast-acting Magneto-Rheological fluid dampers. 
     
     
         4 . The method according to  claim 1 , wherein the ADS includes rotary valve dampers or controllable disc dampers. 
     
     
         5 . The method of according to  claim 1 , wherein the ADS includes and ADS electronic control unit ECU that constantly monitory the VSA-AYC ECU and when the VSA-AYC ECU becomes activated the ADS ECU adjust the front/rear damping force distribution to generate a corrective yaw moment.