中文说明：
本程序能实现专家PID控制。专家控制的实质是基于受控对象和控制规律的各种知识，并以智能的方式利用这些知识来设计控制器。
English Description：
This program can realize expert PID control. The essence of expert control is to design controller based on the knowledge of controlled object and control law in an intelligent way.