中文摘要：

针对无磁液压马达伺服系统对无磁环境的特殊要求,需要将能产生电磁干扰的伺服阀和无磁马达通过长管道远距离配置.为了研究长管道对无磁液压马达伺服系统性能的影响,在精确管道模型的基础上建立了有管道效应的阀控马达伺服系统数学模型,利用计算机仿真分析了管道效应对伺服系统频率响应的影响.仿真结果得出了管道长度、直径和其他系统参数对系统的影响规律,揭示了长管道效应会大幅降低阀控马达伺服系统的液压固有频率和液压阻尼比,并通过实验进行验证.采用三闭环反馈控制策略代替传统的简单比例-积分-微分（PID）控制策略,在一定程度上抑制了管道效应带来的不利影响.

英文摘要：

Non-magnetic hydraulic motor servo system requires that servo valve must stay far away from non-magnetic motor since the servo valve will produce electromagnetic interference which can＇t be ignored.In order to analyze the long pipe＇s influence on the non-magnetic hydraulic servo system,a mathematical model of valve-controlled motor servo system based on precise pipe model was developed and simulated.The research results reveal the law of pipe length,pipe diameter and other related parameters affecting on the system and show that long pipe effects will reduce the hydraulic natural frequency and hydraulic damping by a large margin.The experiments verify the above conclusions,and show that three-loop feedback control strategy instead of traditional simple proportional-integral-derivative（PID） control strategy can lower the adverse impacts owing to long pipe to some extent.