Study On Vehicle ABS Controller Based On Electromechanical Brake System

Electromechanical braking system(EMB) is lately developed braking system.It is driven by electrical wire and transfers signals by data wires,so,it is also called brake-by-wire system. Compared with conventional hydraulic devices EMB is more superior in the following aspects, space saving and less weight,responsive and prompt action,improved stability and efficiency of brake control,enhanced diagnostic capability,environmentally friendly.These make EMB promising and valuable.Automobile anti-lock braking system(ABS) is a device for improving driving safety and vehicle stability.In the situation of emergency braking,ABS prevents the wheel from locking by continuously changing braking force.In this case,the driver will not lose control of vehicle direction.ABS can reduce traffic accident rate.ABS has become a standard component of automobile braking system.In this paper,the mechanical part of a kind of electromechanical braking system has been studied.For the mechanical device,we calculate the parameters of the needed driving motor and choose the appropriate driving motor and the motor driving circuit is designed.In order to choose the appropriate ABS control strategy,firstly,dynamical model of single-wheel vehicle, tire model,hydraulic braking devices model and EMB braking devices model have been built with matlab software,then road surface automatic identification model,fuzzy controller model, PID controller model and Fuzzy-PID controller model has been built.Later on,Three groups of simulation is accomplished with these models,group one is comparison of the ABS control effect of hydraulic braking devices model and EMB braking devices model,group two is comparison of the ABS control effect of the fuzzy controller model,the PID controller model and fuzzy PID controller model,group three is the comparison of the ABS control effect of ABS controller with road surface automatic identification model and ABS controller without road surface automatic identification model in composite road surface.Finally,after the simulation the conclusion is drawn that the fuzzy-PID ABS controller with road surface automatic identification function act best than anyone else.To realize the fuzzy-PID ABS controller with road surface automatic identification function, the ABS main controller is designed with VHDL in QuartuslI environment.The function of fuzzy-PID controller is testified by an experiment.