磁浮軸承是一個非線性的系統，在這篇論文裡我們討論四種不同的非線性控制法則來實用於我們的磁浮軸承系統上。第一種控制法則是傳統的比例積分微分(PID)控制法，它的優點是容易闡述和簡單計算，同時它也是工業界最常用的控制法則。第二種控制法則是比例積分微分模糊增益程序(PID fuzzy gain scheduling)控制法，它說明人們對於比例積分微分增益程序控制的經驗可以用模糊控制法表達出來，並且能改善傳統固定比例積分微分增益值控制法的控制效果。第三種控制法則是滑動(sliding mode)控制法，在我們使用滑動控制法之前我們必須先做磁浮軸承的系統鑑別(system identification)，然後根據系統鑑別所得的結果設計我們的滑動控制法則，滑動控制法對於系統的不確定性和外力的干擾能夠有效的抑制。最後一種控制法則是前饋式適應性控制(adaptive feedforward control)，當系統的質心和幾何中心不在同一點時就會造成不平衡量的產生，前饋式適應性控制主要的就是消除由不平衡量所造成的不平衡力。 The magnetic bearing system is a nonlinear system. In this thesis, we discuss four different controllers. The first controller is PID controller. Its advantages are easily implemented and simple calculated. It is the best-known controller applied in industrial control processes. The second controller is fuzzy gain scheduling of PID controller. The human expertise on PID gain scheduling can be represented in fuzzy rules and it improves the performance of traditional PID controller with fixed parameters. The third controller is sliding mode controller. Before we use the sliding controller, we should do the system identification. And then we use the model from ID to design the sliding controller. The system is completely insensitive to parametric uncertainty and external disturbances when we use the sliding mode controller. The last one is the adaptive feedforward controller. When the principal axis of inertia is not coincident with the axis geometry it will cause an unbalance mass. The adaptive feedforward controller could reduce the unbalance force caused by an unbalance mass.
