Research On Emergency Collision Avoidance Of Electric Vehicles Based On Adhesion Coefficient Estimation

With a series of energy security and environmental pollution problems brought by traditional fuel vehicles,major global car companies have laid out the electric vehicle industry,and the market share of electric vehicles has been rising as a result.Distributed drive is a development trend of electric vehicles,and collision avoidance is one of their key technologies.The vehicle collision avoidance process has strong dynamic characteristics,the braking effect of the vehicle is affected by the road adhesion conditions,and the accurate assessment of the vehicle safety status is inseparable from the real-time recognition of the road condition.Therefore,takes distributed drive electric vehicle as the research platform,and studies its high-speed emergency collision avoidance as follows:(1)A joint simulation model of distributed drive electric vehicle based on CarSim and Simulink software was built with controllable longitudinal velocity and wheel speed estimation by the adaptive sliding mode observer,which will be used as one of the inputs for the estimation of road adhesion coefficient.(2)The suboptimal asymptotic elimination factor is derived using the strong tracking theory and introduced into the root mean square of the prediction error variance array of the square-root cubature Kalman filter algorithm to construct the strong tracking square-root cubature Strong tracking square-root cubature Kalman filter observer is constructed to achieve the estimation of pavement adhesion coefficient.Joint CarSim and Simulink simulations and real vehicle tests were also conducted to verify the validity of the strong tracking square-root cubature Kalman filter algorithm for estimating the pavement adhesion coefficient.(3)Bringing the attachment coefficient into the safety distance model and five polynomial lane change trajectory planning to calibrate the planning decision of the vehicle collision avoidance process,analyzing the effect of adhesion coefficient on vehicle autonomous braking and lane changing,and proposing the collision avoidance logic combining emergency braking to avoid collision,emergency lane change to avoid collision and braking first and then lane change.(4)Through the longitudinal speed controllable distributed drive electric vehicle model,the adaptive model predictive control method with real-time update of the system model is used to develop the lateral control and realize the collision avoidance trajectory tracking of the distributed drive electric vehicle at high speed,and the effectiveness of the collision avoidance logic and trajectory tracking are verified through joint simulation.