Research On Yaw State Estimation And Handling Stability Of Distributed Drive Pure Electric Vehicle

With the change of environment and energy structure,many countries in the world have made a timetable for the withdrawal of fuel vehicles,automobile manufacturers gradually cancel the research and development of internal combustion engine,automobile related industries in all countries are paying attention to and research and development of new energy vehicles,electric drive vehicles is a new trend in the development of the automobile industry since the21 st century.In the context of the rapid progress of the new energy vehicle industry,the supporting three-power technology is becoming more mature,automobile products are becoming more and more abundant,core technologies are becoming more and more mature,and more and more consumers accept new energy models.Distributed drive electric vehicles have also become a research hotspot in the current field.Distributed drive pure electric vehicle has eliminated the engine and transmission system,one of the important characteristics is that it has more controllability,which has great potential for improving the dynamic stability control performance.But in the process of vehicle driving,center of mass of side-slip Angle,yawing angular velocity and estimate the state of the automobile,such as can also affect the yawing stability control of the car,in this paper,the distribution state of pure electric vehicles horizontal pendulum drive type and stability study,in order to choose appropriate stability control strategy,make sure the vehicle is under limit conditions can also be stable.(1)10 degrees of freedom vehicle model is established,considering the car,and the longitudinal and transverse,vertical and lateral tilt,horizontal pendulum,pitch and wheel vertical movement,the "magic formula" tire model,the analysis of vehicle under different road conditions,tire cornering force of longitudinal force,according to the existing structure and the characteristic parameters of real vehicle platform,complete set for car model as a whole,According to the characteristic parameters of the hub motor,the dynamics model of the hub motor is established based on Simulink,which provides a model basis for the next step of yaw state estimation and stability control strategy research.(2)A vehicle driving state estimation control algorithm based on extended Kalman filter(EKF)is used to improve the observation accuracy,and the iterative extended Kalman filter(IEKF)is designed,and the simulation is carried out under the driving condition of double lane shift and steering wheel Angle step input.The results show that: IEKF is superior to EKF in the estimation of vehicle yaw state,and the former can track the real value of vehicle yaw state in real time and achieve noise filtering effect,which can be used as an effective input of yaw stability control system.(3)Considering the basic principle of the structural design of the yaw stability control system,the control variables were selected as the sideside Angle of the center of mass and the yaw velocity,and a method was proposed to calculate the state expected value of the sideside Angle of the center of mass and the yaw velocity using the linear two-degree-of-freedom model.The control strategy was studied,and the characteristics of various control strategies were analyzed.Synovial control was used as the yaw stability control strategy.Through the synovial additional horizontal pendulum control module and output torque,and road adhesion coefficient,centroid side-slip Angle and other factors into consideration as a whole,the weighted additional yawing moment and translated into weighted additional braking force,the latter corresponding performance parameters used in the construction of the whole vehicle model,yawing stability control strategy applied to the modeling of all process,The simulation results of the designed control algorithm are verified.Finally,the MATLAB/Simulink model was built and simulated.The results show that the synovial control algorithm can be used as a control strategy for yaw stability and can maintain the stable driving of the vehicle.