双线法与横摆角速度法联合的车辆稳定性判据

车辆稳定性判据决定了车辆稳定性控制系统的介入与退出时机，是车辆稳定性控制的基础.设计了一种基于相平面法的车辆稳定性判据，在传统双线法确定的稳定区域中引入横摆角速度法确定的稳定区域，设计联合车辆稳定性判据，协调对质心侧偏角和横摆角速度的控制，并获取稳定性判据的相应阈值变化的数据库，用于在控制过程中查表获得车辆的稳定区域边界.利用质心侧偏角和横摆角速度偏离函数表征控制变量偏离参考值的程度和车辆状态相对稳定区域边界的位置.极限工况下，当车辆状态超出稳定区域边界时，车辆稳定性控制应迅速介入，控制车辆状态回到稳定区域.
Vehicle stability criterion is the basis of vehicle stability controls and decides the control intervention time and exit time. A phase plane method based criterion combing the sideslip angle method and the yaw rate method is proposed, which can coordinate the control of both vehicle sideslip angle and yaw rate. By means of phase plane method the data bases of the stable region thresholds are obtained, which contributes to establishing look up tables of the thresholds for real time control. Deviation functions of the sideslip angle and the yaw rate are designed to indicate the deviation between vehicle actual states and the reference states. Meanwhile, relative positions of the vehicle states and the stable region boundaries are also described by the deviation functions. When the vehicle states are beyond the stable region, the vehicle stability control should intervene timely to make the vehicle back to stable state