位置扰动型电液力控制系统多余力的抑制

在位置扰动下,电液力控制系统中液压缸被动运动引起强迫流量,导致多余力的产生。为了减少多余力对系统跟踪性能的影响,首先建立位置扰动下的电液力控制系统数学模型,分解出多余力表达式,在此基础上提出采用一个与系统中电液伺服阀主阀芯运动方向相反的补偿用电液伺服阀来消除多余力的方案,然后以一个典型的液压系统为例,借助Simulink软件进行数值仿真分析。结果表明,补偿阀能够及时、有效地排出强迫流量并大幅减少多余力,位置扰动下多余力减少量最多达93.5%,输出力跟踪幅值误差不大于2%,稳态误差不大于1.8%。

Suppression of superfluous force in electro-hydraulic force control system with position disturbance

Passive movement of the hydraulic cylinder subjected to position disturbance in electro-hydraulic force control system gives rise to forced flow that leads to superfluous force. To reduce the influence of superfluous force on its tracking performance, mathematical model of the electro-hydraulic force control system with position disturbance was established, and the expression of superfluous force was extracted. On the basis of this expression, a scheme of adding a compensating electro-hydraulic servo valve, whose spool moved in the opposite direction of the main electro-hydraulic servo valve spool in the system, was proposed to eliminate the superfluous force. The numerical simulation of a typical hydraulic system was carried out by means of Simulink software. The results verify that the compensating valve can effectively discharge the forced flow in time and significantly suppress the superfluous force. The maximal reduction of superfluous force is 93.5%, the amplitude error of output force is less than 2%, and the steady error is less than 1.8%.