The traditional linear constantparameter PID controller is very difficult to achieve the satisfying results.
传统的线性常参数PID控制器很难取得非常满意的效果。
2
The transmission of the earth wave is stable, hardly influenced by climate and its channel parameter does not change with time basically, it is ConstantParameter Channel.
地波传播受天气的影响较小，比较稳定，信道参数基本上不随时间的变化而变化，是恒参信道。
3
A design procedure with constantparameter frequency method is developed for the temperature control system with variable parameter applicable especially to thermodynamics.