Design,Optimization And Bench Tests Of A Magnetorheological Brake-by-Wire Prototype

Brake-by-wire actuators are the basis of intellectualization and electrification of automobiles.It's a worthy subject to design and develop a high-performance brake-bywire actuator,and provide a reliable test bench for the related experiments of the brakeby-wire system.Magnetorheological fluid is a typical smart material,magnetorheological fluid exhibits instantaneous,reversible and precisely controllable rheological characteristics under an external magnetic field,which provides a theoretical basis for the research and design of automotive brake-by-wire.The braking torque is matched for a mini car in this paper,and a multi-disc magnetorheological brake(MRB)is designed and developed.The finite element analysis of electromagnetic simulation by ANSYS,and the micro-element method is proposed and used to accurately calculate the braking torque of the brake.In order to improve the mechanical characteristics and weight optimization design of MRB,the magnetic circuit design and multi-objective structure optimization are carried out through ANSYS/APDL to complete the parameterized program design and development.The results of optimized design show that the total mass of the MRB has dropped by 6.2% under the premise of meeting requirements of braking torque,and the requirements of weight optimization design have been completed.The MRB prototype development is carried out according to the optimized parameters.Building a calibration test bench for mechanical characteristic,the experiments about the braking torque and response time is competed separately and analyze the experimental results.It provides an effective reference to design the controller of the magnetorheological brake-by-wire system.The test bench for ABS is built.The design of the brake system controller and the development of the software system interface based on Lab VIEW is competed,and the single-wheel ABS control experiment is carried out.The experimental results show the ABS experiment has certain control effect and slip rate is controlled within a reasonable range under the different road adhesion coefficients.Finally,the transfer function of MRB brake torque is identified according to the calibration experiment data,and the working characteristics of MRB are accurately simulated.The MATLAB/Simulink brake system simulation model is built to further study the MRB hysteresis problem.The simulation results show that the MRB can quickly and accurately achieve the control effect.