以LQG/LTR為基礎之伺服馬達之電流迴路穩健PI控制器設計

Abstract

電流迴路是運動控制架構最內層的迴路控制，為一個伺服驅動系統輸出力矩所在。本研究從最內的電流迴路來著手，為使電流迴路在負載變動下能保持一定的穩健效果，在原有的PI控制電流迴路之外，另設計一個兩輸入兩輸出的穩健式PI控制器，所設計的PI控制系統的設計模式相似於LQG/LTR之設計模式。因此，LQG/LTR的穩健效果與性能、條件就可以由簡單的PI控制器來實現，以達到良好的輸出行為與穩健的效果。 本實驗利用德州儀器公司生產的TMS320F240單晶片與鑫鼎公司生產的驅動器及永磁式交流同步馬達來實現。模擬與實驗結果指出當受到負載變動時，加入穩健控制器的電流迴路有更佳的控制性能及解耦效果，因此，其線性程度有所改善，亦帶動了速度迴路的改善。

The current loop is the innermost frame of servo systems, and plays a very important role in motion control. In this thesis, a robust PI control design for the current loop is proposed for servo motor drives. The LQG/LTR control design process can be approximated by reformulating the PI-controlled processes. Thus, robust properties and control performance of LQG/LTR controller can be reserved. All experiments are implemented on the TI TMS320C240 DSP microcontroller and the Headline permanent magnetic synchronous motor. Both simulation and experimental result indicate that the bandwidth of both current loop and velocity loop is improved by applying the proposed robust PI control. Furthermore, the frequency responses becomes more robust as external loads are applied.