Study On The Control System Of Motor Anti-lock Braking System In Electric Vehicle

Motor anti-lock braking control system makes full use of its advantages such as responsing quickly, high control precision and energy recovery, it can improve vehicle`s braking performance significantly and realize the regenerative anti-lock braking control, so as to improve the comprehensive utilization of energy in vehicle. But motor braking torque is smaller and affected by factors of rotational speed, motor parameters, and power system and so on, how to solve these problems to realize regenerative anti-lock braking control is an important issue. Based on these problems, this paper mainly includes the following aspects:Firstly, The braking current, efficiency of energy recovery and brake torque variation of brushless dc motor under full and half bridge modulation are analyzed, and the results of theoretical analysis is proved by simulation. The results show:Motor under full bridge modulation has a wide range of torque control, small current ripple and strong stability; motor under half bridge modulation has high energy recovery.Secondly, the double-loop control system of motor anti lock braking adjusted by duty cycle is designed. The outer loop is slip control based on fuzzy sliding mode control, fuzzy control is adopted to solve the problem of chattering; the inner loop is current control. Based on the motor braking strength and energy recovery efficiency, its conditions are designed.The simulation model of motor anti-lock braking double loop control system is conducted, the effectiveness, reliability and stability of system designed in this paper are proved through the simulation in various road conditions.Finally, the hardware-in-the-loop test bench of motor anti-lock braking system is putting up, and the system designed is tested with it.The results from the simulation and experiment show: the control methods designed in the paper, can realize the motor anti-lock brake successfully, and make the regenerative anti-lock brake realization. The system resposes quickly, with good braking stability and reliability. This paper provides a theoretical basis and new ideas for the development and design of motor anti-lock braking control system...