Design And Research Of Brake Pedal Feeling Simulation Device Based On Magneto-Rheological

With the rapid development of electronic control technology,brake-by-wire has become the mainstream in the future development of automobile brake system.The brake-by-wire system cancels the mechanical connection between the pedal and other mechanisms,and directly controls the actuator’s braking behavior through electric signals.Therefore,in the process of automobile braking,the brake-by-wire system cannot directly provide pedal feeling feedback to the driver.A brake pedal feeling simulation device is needed to provide the pedal feeling similar to the hydraulic brake system for the driver.At present,the common brake pedal feeling simulation device is mostly based on the design of the spring,rubber and other passive components.This kind of feeling simulation device can only simulate the linear brake pedal feeling,and once the structure is determined,it can only simulate a specific pedal feeling.In this paper,a kind of brake pedal feeling simulation device based on MR damper is proposed.The advantage that MR damper can output continuous controllable damping torque is utilized to realize the simulation of various nonlinear brake pedal feeling.The main research work includes:(1)The feeling of brake pedal and its characteristic curve are studied and analyzed.Through the analysis of automobile braking process,the definition of brake pedal sensation is defined,and the formation mode and type of automobile braking characteristic curve are studied.Then through the analysis of the influence factors of the pedal feeling of the hydraulic brake system and the brake-by-wire system,the desired form of the ideal pedal characteristic curve is obtained.(2)The design of the brake pedal feeling simulation device based on magnetorheological is completed.Firstly,the basic principle of realizing nonlinear brake pedal feeling simulation by magnetorheological pedal simulation device is analyzed.Then the basic structure of the pedal feeling simulation device is designed and its working principle and characteristics are described.Finally,the maximum damping torque provided by the damper is obtained through dynamic analysis of the pedal feeling simulation device.(3)A single-disc magnetorheological damper is designed to meet the requirements of the brake pedal feeling simulation device.According to the basic structure of the single-disk MR damper,and the design dimensions of MR damper are determined by magnetic circuit design.Then the magnetic circuit simulation analysis of the designed damper is carried out in ANSYS to verify the rationality of the damper structure design.Finally,the structure of the MR damper is optimized.After the optimization,the structure of the damper is more compact and the magnetic induction intensity distribution is more reasonable.(4)In the MATLAB/Simulink environment,the control simulation analysis of the brake pedal feeling simulation system based on MR damper is carried out.The single neuron adaptive PID control strategy is adopted to track and control the brake pedal characteristic curves under three different working conditions of emergency braking,conventional braking and low-speed braking.The simulation results show that the brake pedal feeling simulation device based on magnetorheological can simulate the various nonlinear brake pedal feelings under different working conditions.