Research On Coordinated Control Strategy Of Electro-hydraulic Compound ESP For FSEC Electric Formula Racing

At present,the research on stability control of electric formula cars mainly focuses on the single control of pure hydraulic ESP or DYC,and less attention is paid to the research on electro-hydraulic composite coordinated control.This paper takes the FSEC racing car of North Central University as the research platform,in order to improve the driving stability of the racing car,the coordinated control strategy of the electro-hydraulic composite ESP of the racing car is studied.The main research contents are as follows:Firstly,starting from the feasibility and necessity of the electro-hydraulic composite ESP coordinated control under extreme conditions,through the analysis and research of the composite optimization mechanism of the electro-hydraulic composite ESP system,the effect of the electro-hydraulic composite on the driving stability of the electric formula car is explained.Based on the improvement effect,the idea of the electro-hydraulic composite ESP coordinated control strategy of the racing car is proposed,which provides theoretical support for the formulation and simulation verification of the subsequent electro-hydraulic composite layered control strategy.Secondly,for the estimation of the actual centroid sideslip angle of FSEC racing cars,an estimation method based on unscented Kalman filtering is proposed,and the corresponding centroid sideslip angle estimator is designed.The effectiveness of the estimator in estimating the centroid slip angle under extreme conditions.Then,the research on the coordinated control strategy of the electro-hydraulic composite ESP is carried out.Based on the hierarchical control theory,this paper designs a control strategy with the center of mass slip angle and yaw rate as control variables for the purpose of reducing the system’s target overlap and optimizing the redundancy allocation.The upper controller is the decision-making layer and adopts the sliding mode variable structure algorithm;the lower controller is the torque distribution layer,which adopts the torque quadratic distribution method based on the minimum tire usage rate to distribute the in-wheel motor torque and hydraulic pressure to each wheel to achieve Differential braking.Finally,CarSim and Simulink are used for co-simulation to establish the vehicle dynamics model and control system model of the Zhixing FSEC racing car.Aiming at the road conditions with low adhesion coefficient,the continuous sine function is used to simulate the steering angle input,and the two extreme conditions of single lane shift and emergency double lane shift are simulated to study the racing track,yaw rate,center of mass The influence of factors such as slip angle on stability.By comparing and analyzing the actual control effects of the electro-hydraulic composite ESP coordinated control,the pure motor DYC control and the pure hydraulic ESP control,the results show that: under the limit conditions,compared with the single system control strategy,the electro-hydraulic composite ESP coordination control designed in this paper The control strategy can better control the racing car and effectively improve the handling stability of the racing car.