Research On Lateral Stability Control Of Vehicle Under Limit Conditions

When the vehicle driving on the low adhesion road or going on a high speed sharp turn on the high adhesion road, it is prone to lateral stability problems, such as yaw, sideslip or rollover. With the development of science and technology, control technology and electronic products have been widely used in the vehicle, the vehicle stability control system is also increasingly mature, to a large extent, improve the lateral stability of the vehicle. However, most stability control systems set yaw stability as the main control target at present, although the occurrence of rollover accidents can be inhibited to a certain extent, it plays a limited role under extreme conditions such as high speed sharp turn. In order to compensate for the vehicle stability control system in the anti-rollover control, it is necessary to set the rollover stability as a control target of the vehicle stability control system, and research the combined control strategy of yaw stability and rollover stability.Firstly, the main factors affecting the lateral stability of vehicle, basic principles and methods of lateral stability control were discussed; then the simplified vehicle model of two degrees freedom was established to analysis of the steady-state response, and the particularity of vehicle lateral stability under extreme conditions was studied. In the process of model building, the vehicle dynamic model was established by the CarSim software based on parametric modeling, including the transmission system, braking system, tire model and other subsystems. Based on the control principle of the traditional automotive electronic stability controller, the parameters adaptive fuzzy PID controller with the yaw rate as the control target was established to control the yaw of vehicle; Based on LTR anti rollover control theory, the rollover stability controller was designed through the traditional sensor signal static threshold value control method. Then introduced an integrated control strategy can achieve the yaw and rollover stability control, by monitoring the state of the automobile, made a judgment on the priority order of occurrence of vehicle yaw and roll motion and preferentially activated the corresponding stability control strategy, then realized the yaw and roll dynamics stability control. Finally, the yaw and rollover integrated control strategy had carried on the simulation analysis under different conditions, verified the validity of the CarSim vehicle model and control strategy.