静液压驱动车辆加速过程动态特性研究

Study on Dynamic Characteristics of Hydrostatic Driven Vehicle Acceleration Process

针对配备双变量机构的静液压驱动车辆,以实现车辆最大加速能力为目标,对车辆加速过程变量机构控制策略和系统动态特性进行研究。首先从理论上分析实现车辆最大加速能力的驱动系统理想输出特性,得到泵、马达排量随马达转速的变化关系。进一步分析静液压驱动系统容积效率对车辆加速性能的影响,得到实际控制量与理论控制量之间的修正规律。为解决实际系统容积效率难以获取的难题,提出容积效率修正因子以及速比闭环反馈控制的方式,对泵和马达的理论排量进行修正,提出实现车辆最大加速能力的泵马达排量控制策略。通过仿真和试验对所提控制策略进行了验证,试验结果表明所提出的控制策略能够使车辆实现较好的加速性能,证明控制策略的可行性,具有较好的适应能力。

In order to achieve the maximum acceleration capability of a hydrostatic driven vehicle equipped with a dual variable mechanism,the variable mechanism control method and drive system dynamic characteristics during vehicle acceleration are studied.The ideal output characteristics of the drive system to achieve the maximum acceleration capacity of the vehicle are analyzed theoretically,and the relationship between the displacement of the pump and the motor and the speed of the motor is obtained.Furthermore,the influence of the volumetric efficiency of the hydrostatic drive system on the vehicle acceleration performance is analyzed,and the correction law between the actual control and the theoretical control is obtained.In order to solve the problem that it is difficult to obtain the volumetric efficiency of the actual system,the volumetric efficiency correction factor and the speed ratio closed-loop feedback control method are proposed,the theoretical displacement of the pump motor is modified,and the pump motor displacement control method to achieve the maximum acceleration capacity of the vehicle is obtained.The proposed control method is verified by simulation and test.The test results show that the proposed control method can make the vehicle achieve better acceleration performance,and the feasibility of the proposed control method is proved.