Study On Composite Brake Control Strategy Of Battery Electric Vehicle Based On Fuzzy Neural Network

The brake system is the key to safe driving of the car.The battery electric vehicle uses the motor as the power output device of the whole vehicle,and adopts a composite braking system composed of hydraulic braking and regenerative braking.In order to ensure the recovery of the maximum braking energy under the premise of battery electric vehicle braking safety,a hybrid braking control strategy based on fuzzy neural network for battery electric vehicles is proposed to rationally distribute the regenerative braking force and the hydraulic braking force of the front and rear axles in the composite braking.Firstly,according to the vehicle parameters and performance objectives,the permanent magnet synchronous motor is selected and its power,speed and torque parameters are determined.The lithium ion battery is selected and its voltage and capacity parameters are determined.Based on the Cruise environment,the vehicle system,battery,motor,final drive,wheel,cab and brake module model are established.Through simulation analysis,it is reasonable to verify the matching result.Secondly,the basic structure and working principle of the hybrid brake of battery electric vehicles are analyzed,and combined with three typical composite brake control strategies,a composite brake control strategy based on fuzzy neural network is proposed.According to the vehicle braking dynamics and ECE regulations,the distribution coefficient range of the front and rear axles during composite braking is determined.Through the target nonlinear programming method,the optimized front and rear axle braking force distribution coefficient is determined to be 0.735.Combined with the theory of fuzzy neural network,a three-input and single-output regenerative braking force distribution controller is designed to determine the proportion of regenerative braking in composite braking.Finally,according to the above-mentioned composite brake control strategy,the regenerative braking force and the front and rear axle hydraulic braking force during composite braking are determined.The composite brake control strategy model is established in MATLAB/Simulink environment,and import it into the Cruise environment in MATLAB-DLL.The Cruise-Simulink co-simulation is performed.The results show that the braking energy recovery rate of the composite braking control strategy proposed in this paper is improved by 3.52% under the premise of ensuring the safety of braking.The composite brake control strategy proposed in this paper not only provides new ideas for the theoretical innovation of battery electric vehicle composite brake control,but also can improve the economy of battery electric vehicles and improve the cruising range,which has certain practical significance.