Research On EMB Clamping Force Control Strategy And Development Of Experimental Platform

With the increasing development of automotive electronics,automobiles are constantly moving in the direction of intelligence.At the same time,people are increasingly demanding the safety performance of automobiles.Brake-by-wire is an advanced electric control actuation system,which is very different from the traditional car hydraulic brake system both in structure and in principle.Electro-mechanical brake(EMB)is the main branch of the wire control system and is the future development direction of the automotive brake system.At the same time,the anti-lock braking system(ABS)as an active safety device has important significance in improving the safety and operational stability of the car,and has become the standard of the car.The research will be conducted as following:The overall design requirements of the EMB actuator were determined.The various components of the EMB actuator,including the permanent magnet brushless DC torque motor,planetary gear reducer,and ball screw,were selected and designed.At the same time,the corresponding mathematical models and simulation models for each component have been established.A gap adjustment control strategy based on current signal recognition is proposed so as to achieve automatic adjustment of the braking gap of the EMB system.In order to improve the accuracy of recognition,a second-order Kalman filter algorithm is designed to filter the current.On this basis,the structure of EMB brake closed-loop control is determined,and the clamping force control strategy based on fuzzy PID is designed,and simulation verification is carried out in Matlab/Simulink.The simulation results show that compared with the PID control algorithm,the fuzzy PID control algorithm has better dynamic performance,stronger robustness,and the overall EMB control system performance meets the design requirements.At the same time,A hardware-in-the-loop(HIL)experimental platform for EMB which based on dSPACE real-time simulation system was set up.The real-time EMB brake model was established and the host monitoring and data recording software based on ControlDesk was designed.The experiment verifies the effectiveness of the clearance adjustment control strategy and the effectiveness and rationality of the EMB brake clamping force control algorithm.A half-vehicle and tire model was constructed,the ABS control architecture was designed,and the EMB system and ABS system were integrated.The overall design of the upper brake force control of the EMB is implemented,and automatic switching between emergency braking and conventional braking is realized.An ABS controller based on the EMB braking system was designed.The results of the joint simulation of CarSim and Simulink show that this controller has better braking effect than the conventional braking force distribution controller,avoids the danger of wheel locking and improves the vehicle's handling stability.