摘要
电液制动系统轮缸压力变化特性直接影响制动器夹紧力控制,由于存在机、电、液严重耦合现象,难以精确建模表达。考虑轮缸初始压力和占空比两个因素,以稳态压力变化值代表压力变化率进行试验研究,绘制了轮缸压力变化MAP图,并对MAP图进行分析。结果显示:轮缸稳态压力变化值随轮缸初始压力变化存在拐点,该拐点为轮缸活塞运动终止压力,本系统中该压力为2.8 MPa;轮缸稳态压力变化值与占空比之间呈线性关系,但由于开关阀开关特性的差异,直线未经过原点,增压过程中,直线与横轴交于占空比3%附近;减压过程中,直线与横轴交于占空比-5%附近。该压力特性研究以MAP图的形式表达了系统的非线性特性,并找出了系统中具有线性关系的部分,有助于下一步的制动器夹紧力控制研究。
The electro-hydraulic brake（EHB） system consists of mechanical,electromagnetic and hydraulic parts.The pressure characteristic of its wheel cylinder is essential to the brake force modulation.But this characteristic is hard to be expressed with theoretical models because of the heavy nonlinearity and coupling of the system＇s main parts.In the research,the experiments are carried out to study this characteristic.The essential affecting factors considered in the experiment design contain the initial pressure and the duty cycle of PWM signal.The stable variation MAP is got from the experimental results.The analysis shows that there are the inflection points in the stable variation value and initial pressure curves.The inflection point is defined as the piston travel end pressure.In this system,the pressure is 2.8 MPa.The analysis also shows that the relationship between the pressure variation and duty cycle is linear.But the line does not go across the origin point.The cross point is at 3% of the duty cycle during pressurizing,while it is at-5% of the duty cycle during depressurizing.In the research on pressure characteristics,the nonlinear characteristics of the system are expressed by MAP,and some parts with linear relation in the system are found.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2013年第8期1013-1020,共8页
Acta Armamentarii
基金
国家自然科学基金项目(51005113)
电动车辆国家工程实验室科技支撑计划项目(2012年)
关键词
机械学
电液制动系统
轮缸压力
高速开关阀
mechanics
electro-hydraulic brake system
wheel cylinder pressure
high speed valve
