对接模拟并联六自由度平台的模糊免疫PID控制

Fuzzy-immune PID control of a 6-DOF parallel platform for docking simulation

以电液伺服并联六自由度平台为研究对象,讨论了对称阀控非对称缸数学模型各部分的作用.针对外负载扰动的不确定性,提出了将免疫算法引入增量式PID(比例、积分、微分)控制器,并推导了控制律.为增强系统的稳定性和鲁棒性,采用模糊策略逼近抗体抑制调节非线性函数,并设计了模糊免疫PID控制器,将该控制器应用到空间对接半物理仿真六自由度平台中,建立了分级实时控制系统,针对系统结构参数大变化和提高跟踪响应频率设计了两组实验.结果表明,所设计的模糊免疫控制器作用良好,平台在6个自由度的实时跟踪和协同控制性能均获得满意的结果.

Taking a hydraulic/electronic servo and six degrees-of-freedom （6-DOF） parallel platform as object, the function of every part in the mathematical model of symmetric valve-controlled asymmetric cylinder was discussed. Because of the uncertainties of load disturbance, immune algorithm was introduced into the incremental proportion-integral-derivative （PID） controller, and the control law was deduced. A fuzzy logical algorithm was adopted as anti-body-suppressed function to improve the stability and robustness of the system, consequently a fuzzy immune PID controller was designed. This controller was then imbedded to a cascade real-time control system which was applied for the semi-physical docking simulation of the 6- DOF platform. Two groups of experiments were designed aiming at the distinct changes of structure parameters and the improvement of frequency response respectively. The results showed that the fuzzy immune PID controller performs well, and the real-time tracking of all 6-DOFs and the synergetic control ability were satisfying.