Research On Control Strategy Of Collision Avoidance System For Electric Vehicles Based On Sliding Mode Control

With the development of automobile industry,the active safety of automobile has been paid more and more attention,which is the most promising subject of vehicles technology research.Vehicle active collision avoidance system is designed to improve traffic safety as the goal of the early warning assistance system,and electric vehicles is the emerging automotive industry.At present,there are still many problems in the research of active safety collision avoidance system for pure electric vehicles.Based on this background,this paper focuses on the longitudinal braking collision avoidance,the lateral lane changing collision avoidance and the stability of the channel,the corresponding controller design,and the corresponding theoretical research and simulation analysis are carried out.The main contents of this paper include the following aspects:(1)According to the proposed new structure suitable for pure electric vehicle powertrain system,a pure electric vehicle dynamics system model is constructed.Including: the pure electric vehicle seven degrees of freedom vehicle model,acceleration model,brake model.(2)A variable time headway strategy considering the relative acceleration of the vehicle is proposed.According to the longitudinal braking process,the safety distance model is established,and the longitudinal hierarchical controller is designed based on sliding mode theory.The upper controller controls the vehicles expected state according to the established safety distance strategy.The lower controller determines the accelerator pedal opening degree or the braking pressure by the actuator logic judgment so that the actual running state of the vehicle is consistent with the expected running state,to achieve the initiative of the vehicle collision avoidance function.(3)A lateral change of vehicle collision avoidance system based on the sliding mode theory is proposed.Firstly,the trajectory of the traverse path based on the yaw angle model is designed.Then,the operational stability controller is designed based on the sliding mode control method.The system is controlled by the side angle control,which makes the vehicle track the ideal track path quickly and accurately.To sum up,the vehicle collision avoidance controller has been designed in this paper can effectively achieve the vehicle safety and stability collision avoidance function requirements,for promoting traffic safety,reduce traffic accidents,improve traffic efficiency is of great significance.