Patent ID: 7571039
Filing Date: 2009-08-04
Classification: B60G,Y10S

Abstract:
1. A rollover avoidance system for changing the damping characteristics of suspension dampers at each wheel of a vehicle to mitigate a potential rollover condition, said system comprising: a speed sensor providing a vehicle parameter speed signal of the speed of the vehicle; a roll rate sensor providing a vehicle parameter roll rate signal of the roll rate of the vehicle; a lateral acceleration sensor for providing a vehicle parameter lateral acceleration signal of a lateral acceleration of the vehicle; a yaw rate sensor for providing a vehicle parameter yaw rate signal of the yaw rate of the vehicle; a hand-wheel angle sensor for providing a vehicle parameter hand-wheel angle signal of the angle of a vehicle hand-wheel; a rollover indicator processor for calculating a roll stability indicator signal; a dynamic command processor for generating a desired stability command signal based on the vehicle parameter signals for a desired stiffness of the dampers; and a closed-loop controller responsive to vehicle parameter signals, the calculated roll stability indicator signal and the desired stability command signal, said closed-loop controller calculating an understeer or oversteer signal based on whether the vehicle is in an understeer or oversteer condition and a yaw stability control factor based on a yaw rate error signal and a side-slip error signal, said closed-loop controller further determining a roll error signal as the difference between the desired stability command signal and the calculated rollover stability indicator signal, said closed-loop controller also calculating a gain signal as a function of the vehicle speed signal, said closed-loop controller further calculating a closed-loop roll control factor based on the gain signal and the roll error signal, said closed-loop controller also determining a front to rear damper distribution of the damping characteristics of the suspension dampers based on the yaw rate error signal and the understeer or oversteer signal, said closed-loop controller generating a damper suspension command signal for each damper based on the front to rear distribution signal and the closed-loop roll control factor or the yaw stability control factor.