IMC-PID是利用内模控制原理来对PID参数进行计算，可直接计算得到多重分形谱,二维声子晶体FDTD方法计算禁带宽度的例子。- The IMC- PID is using the internal model control principle for PID parameters is calculated, It can be directly calculated multi-fractal spectrum, Dimensional phononic crystals FDTD met