中文摘要：

针对电液负载模拟系统存在多余力且该多余力严重影响系统加载精度与控制性能的问题,建立了系统各部分以及整个系统的数学模型.通过对数学模型的研究,分析了系统多余力的产生机理,并建立了系统多余力的传递函数.提出了前馈PID复合控制的方法,并对该方法进行了仿真分析和实验研究.在仿真分析中,通过对多余力消扰前、引入前馈控制消扰后及引入复合控制消扰后3种情况的比较,说明前馈PID复合控制能够有效抑制系统多余力.实验结果进一步验证了前馈PID复合控制的有效性,同时实验结果显示在运动换向时系统多余力将出现突变,为下一步的研究指明了方向.

英文摘要：

In order to restrain the surplus force caused by position disturbance in the aircraft rudder electrohydraulic load simulator and improve accuracy of the loading system, the mathe- matical model for each part and the whole system was established. Through the analysis of the mathematical model, the generation mechanism for the surplus force was expounded, and the transfer function for the surplus force was established. A compound control method was pro- posed which combined PID and feedforward compensation. The numerical simulation and the experimental study were carried out based on the proposed method. The results of simulation and experiment show that, the feedforward PID compound control can effectively restrain the system＇ s surplus force, so as to improve the loading accuracy of the electrohydraulic load sim- ulation system. At the same time, the experimental results show that the surplus force hits a mutation when the system changes the direction of movement, which points out the direction for further research.