Study On State Parameter Estimation And Lateral Active Collision Avoidance Control For Electric Vehicle

Traffic safety is becoming more and more complicated,and the passive collision avoidance system of vehicles has been unable to meet the requirements of modern transportation.Automobile manufacturers have expanded product research and development efforts to promote the development of the automobile industry in the direction of intelligence.The development of active vehicle collision avoidance systems with prevention as the core has become a trend in modern transportation,but at this stage,vehicle active collision avoidance systems are mainly focused on longitudinal collision avoidance,and lateral collision avoidance systems are relatively rarely mentioned.This paper studies the vehicle side active collision avoidance control system from the aspects of electric vehicle state estimation and control strategy.The content is as follows:First of all,the research background of the vehicle side active collision avoidance system is described,and the framework of the system is built from four aspects: traffic information perception and processing,lane change safety distance model,vehicle dynamics control and vehicle modeling.Secondly,on the premise of not affecting the control effect,the vehicle model is simplified,and the body dynamics model,wheel dynamics model,and tire model are established to provide a mathematical model for the design of subsequent vehicle observers.Thirdly,vehicle sideslip angle and tire sideslip stiffness are important parameters of vehicle handling and stability.In this paper,unscented Kalman filter is used to estimate vehicle body sideslip angle,recursive least square method with forgetting factor is used to estimate tire sideslip stiffness,which provides necessary driving state and environmental information for vehicle lateral motion.Finally,a double-layer controller is designed to control the lateral stability of the vehicle.Design the upper controller to obtain the desired trajectory of the vehicle's lateral collision avoidance,that is,the expected yaw rate and the desired body deflection angle;design the direct yaw moment adaptive sliding mode controller to obtain the steering torque of the vehicle to achieve stable and safe obstacle avoidance.