常规的比例-积分-微分(PID)控制器一般用于单输入单输出系统。对于具有多个输入和多个输出且相互之间具有较强耦合作用的高阶多变量系统,PID控制器的设计常难以实现。针对高阶柔性结构振动控制问题,提出如下PID控制策略:首先在某一频段内对频响函数进行拟合降阶,建立过程模型,然后采用内模控制方法和麦克劳林展开式设计多输入多输出振动系统PID控制器。以4层刚架进行建模仿真计算,结果表明,通过本文方法设计的PID控制器,可以在避免未控模态影响的前提下,使外部干扰得到有效抑制,得到比较理想的控制效果。
Traditional proportion-integral-derivative (PID) controllers are generally used in single-input-single- output (SISO) systems. It is very difficult to design a PID controller for a multiple-input-multiple-output (MI- MO) system which has intensive interactions among input and output degree of freedoms. In this article, a new design is put forward for the application of PID controller to the vibration control of high-order flexible structures. A reduced-order model is obtained by curve fitting of the frequency response functions in a specified frequency range and the process model is created. The PID controller for vibration control of a MIMO system is then designed using the internal model control (IMC) method with Maclaurin series expansion. A four-tier rigid frame is used to simulate the PID controller design process, and the results show that the technique presented in the article for the design of the PID controller is effective in rejecting the adverse effects of the uncontrolled modes and controlling external disturbances. The vibration control results of the four-tier rigid frame are satisfactory.