斜盘控制策略下液压系统位置控制及性能分析

Position Control and Performance Analysis of Hydraulic Systems Under Swashplate Control Strategy

为提高液压系统位置控制的响应速度及准确性,研究斜盘控制策略下液压系统位置控制及性能。从液压系统位置控制电路的构造出发,对控制策略进行描述。通过泵速求取电动机的动力学方程,利用电机转子的电动势计算电动机转矩。以滑模控制方法作为两种液压系统的控制核心,并在MATLAB/Simulink下对斜盘控制系统进行建模。在所构建斜盘控制模型的基础上,对比分析斜盘控制策略和变频驱动控制策略液压系统位置控制性能。结果表明:斜盘控制比变频驱动控制具有更好的响应性和控制稳定性;跟踪阶跃、正弦参考位置时,斜盘控制比变频驱动控制的控制精度分别提高47.67%和48.58%,斜盘控制比变频驱动控制的控制准确性更好。分析结果表明斜盘控制策略比变频驱动控制策略更适合液压系统的位置控制。

In order to improve the response speed and accuracy of the hydraulic system position control,the hydraulic system position control and performance analysis under the swashplate control strategy were studied.Based on the construction of the position control circuit of the hydraulic system,the control strategy was described.The motor dynamic equation was obtained through the pump speed,and the motor torque was calculated by using the electromotive force of the rotor.The sliding mode control method was used as the control core of the two hydraulic systems,and the swashplate control system was modeled by using MATLAB/Simulink.Based on the established swashplate control model,the position control performances of the hydraulic system were compared and analyzed between the swashplate control strategy and the frequency conversion drive control strategy.The results show that the swashplate control has better responsiveness and control stability than the frequency conversion drive control;the control accuracy of the swashplate control is 47.67%and 48.58%higher than that of the variable frequency drive control respectively when the step and sinusoidal reference position are tracked,the control accuracy of the swashplate control is better than that of the frequency conversion drive control.It is shown that the swashplate control strategy is more suitable for the position control of the hydraulic system than the frequency conversion drive control strategy.