高速开关阀在高频PWM控制下的比例功能

在现代汽车制动系统(如制动防抱死系统(ABS)、电子稳定程序(ESP))中,为了控制制动压力,一般采用电子控制单元(ECU)控制的二位二通的高速开关电磁阀来实现制动轮缸的压力增压、保压和减压的控制。由于传统高速开关阀只能实现开或关两种状态,为了提高系统的控制精度,对高速开关阀的开关比例功能也要求越来越高。该文在MATLAB的Simulink中建立了高速开关阀的脉冲宽度调制(PWM)控制仿真模型,研究了在2～4 kHz的调制频率下,通过改变PWM控制下的占空比,来实现高速开关阀的比例开关功能。并进一步分析了不同参数对高速开关阀PWM控制的比例开关功能的影响。通过本研究,拓宽了高速开关阀的功能应用范围,达到了精密控制制动压力的效果,对汽车ABS和ESP中的高速开关阀的控制提供了参考,从而使得制动压力的增加过程能够更加平稳有度。

High speed on-off solenoid valve with proportional control based on high frequency PWM control

Modern automobile braking systems(such as anti-lock brake systems(ABS) and electronic stability program(ESP)) use an electronic control unit(ECU) to control the brake pressure through a two-status-two-way high-speed on/off valve to build up,hold or reduce the brake pressure.Since traditional high-speed on/off valves have only on/off states,a proportionality function was added to the high-speed on/off valve to improve the control precision.This paper describes a high-speed on/off valve MATLAB-Simulink simulation model using pulse width modulation(PWM) control with a 2～4 kHz modulation frequency used to analyze the proportionality function of the high-speed on/off valve for different duty cycles of the PWM control.The analyses extend application of the high-speed on/off valve to precise control of the brake pressure.This propositional control of the high-speed on/off valve in vehicle systems ABS and ESP makes the brake pressure increase more stable.