Abstract: The single channel electro-hydraulic servo system is a system with nonlinear and time-varying, and has a small damping ratio, parameter varies a lot, high degree of nonlinear characteristics. The traditional PID control is hard to meet the requirements of the control precision of 6-DOF parallel platform. In order to meet the requirements of system control accuracy, this paper uses a genetic algorithm to optimize the parameters of PID controller, in the  mathematical model of single channel electro-hydraulic servo system. The simulation results show that the performance of the control system improves a lot, proves the feasibility and effectiveness of the improved algorithm, overcomes the drawback of traditional PID parameters setting time consuming, provides the effective method to deal with the practical problem and the adaptive （robustness） also improves.

Key words: 6-Degree Of Freedom（DOF） parallel platform, hydraulic servo system, Proportion Integration Differentiation（PID） control, genetic algorithm

摘要： 由于单通道电液位置伺服系统是一种非线性时变系统，而且有阻尼比小、参数变化大、非线性程度高的特点，传统的PID控制已经很难满足六自由度并联平台的控制精度的要求。针对六自由度并联平台单通道的数学模型，采用遗传算法对其PID控制器的参数进行优化控制，以满足系统的控制精度的要求。仿真结果表明该控制系统的性能指标有了很大改善，证明了该遗传算法的可行性和有效性，克服了传统PID整定参数费时的缺点，对解决实际控制问题提供了有效的方法，并且具有良好的抗干扰能力，其适应性（鲁棒性）也有了很大的提高。

关键词: 六自由度并联平台, 液压伺服系统, 比例-积分-微分（PID）控制, 遗传算法