说明：  极其不愿意发出来的滤波器设计文件，本人参与的所有控制相关的项目，一定会用到该文件，理由只有1个，滤波器的参数matlab直接生成。只有了解了滤波器，才算控制入门把！
(The filter design is extremely reluctant to send files, I participate in all control related projects, will use the file, only 1 reasons, matlab filter parameters are directly generated. Only if you know the filter, you can count the control entry.)