Research On Active Control Method Of Electric Vehicle Stability Based On ESO And Sampled-data Output Feedback Control Theory

Today,vehicle safety has become the primary problem in automotive design,as its key issue,vehicle stability has also been a research hotspot in the automotive field.In actual driving,the car will be subject to various disturbances such as road surface,wind power and internal body,sometimes it can’t be effectively controlled by the driver,at this time,the vehicle may suffer from side-slip,tail-streaking and other instability.In addition,in order to reduce the driving burden of the driver and improve the driving experience and the ride comfort,active control of vehicle stability is indispensable.Based on the theory of active disturbance rejection control(ADRC)and domination approach,this paper studies the stability control of the electric vehicle(EV).The main research contents are as follows:(1)Construction of a two-degree-of-freedom(2-DOF)vehicle tracking model.Combining with the classic 2-DOF vehicle model,the actual driving conditions and operation conditions,simultaneously comparing with the derived four-degree-of-freedom(4-DOF)vehicle model,so a 2-DOF vehicle tracking model is constructed.After that,the derived tracking model differential equation is transformed into state equations of two subsystems,and the extended state is performed according to the ADRC theory.(2)The design of the sampling control law based on the hybrid estimation method.Firstly,the coordinate transformation of the extended state equations is carried out and the domination coefficient is introduced.Secondly,the dual-extended-state observers(d ESO)are designed to obtain the estimated value of the unmeasurable states.Then,based on the observers,a sampled-data output feedback control law is constructed,and finally the stability analysis is presented to show that the closed-loop system is globally asymptotically stabilized.At the same time,a sliding mode control(SMC)law is designed as a comparison method,which uses the pole method to determine the coefficient matrix of the switching function and selects the constant reaching law to suppress the unstable part of the controlled object.(3)Numerical simulation analysis based on Matlab.The Matlab software is used to simulate previously designed control methods,and the comparison is performed in the following three aspects: First,under the same external disturbance,a comparison of dual-Extended-State-Observers and Domination Approach via Sampled-data Output Feedback(d ESOD),SMC and no control method verifies the effectiveness of the d ESOD method.Second,comparing the d ESOD method with the classical domination approach,the practicability of the d ESOD method is verified.Third,the performance of the d ESOD method under different vehicle speeds is analyzed.(4)Co-simulation analysis of Car Sim-Simulink.Using Car Sim-Simulink software to test in a near real vehicle environment.And in the simulation,co-simulation models based on d ESOD method,SMC and no control are constructed.Finally,the results of different test conditions are compared,and the simulation results of Matlab are verified.The simulation results show that the d ESOD method designed in this paper can quickly eliminate or effectively suppress external disturbance and improve vehicle handling stability and ride comfort.