本論文探討一個線性馬達驅動之龍門定位系統的控制器設計問題,並研究使用Labview程式語言來實現即時追蹤控制器的設計。由於載台與滑軌之間相互接觸會產生非線性摩擦現象,導致控制器之軌跡追蹤精度的下降,故本文進行非線性摩擦力模型之量測,並透過系統建模與參數鑑別的技術,來設計前饋控制器進行補償。為了得到系統模型與摩擦力模型之最佳化參數,本文使用Matlab/Simulink撰寫粒子群最佳演算法(PSO)來進行系統參數之鑑別以及最佳化參數之分析與模擬。 在前饋控制器之設計方面,本文藉由LuGre 模型來描述非線性的摩擦力行為,並經過前饋(Feed-Forward)控制器的補償設計來消除低速與靜摩擦區間的摩擦力對系統的影響。除了前饋控制器外,亦結合不同的回授控制器來改善平台的追蹤誤差。所探討的回授控制器包含(1)比例-積分-微分(PID)控制器、(2)順滑模態控制器(SMC)、(3)非奇異終端順滑模態控制器(NTSMC)、(4)結合PSO之干擾估測器(DOB)等控制方法。根據雙軸之圓軌跡追蹤與長行程追蹤之實驗結果顯示,PSO之干擾估測器(DOB)控制器可改善因模型鑑別之不確定性或外在干擾等所造成的追蹤誤差,相對於其他方法具有較佳的控制性能。
A linear motor actuated gantry stage is investigated in this study, where the proposed controllers are implemented using Labview to perform the real-time tracking control. Because the nonlinear friction between the stage and the guider degrades the tracking accuracy of the controller, the feed-forward controller based on the nonlinear friction model is studied to improve the performance of the controller. A particle swarm optimization (PSO) is used for identifying the parameters of the friction model to obtain the optimal friction model. For the feed-forward compensation, the LuGre model is studied and used to describe the nonlinear friction for the feed-forward compensation. In study, four types of feedback compensations are integrated in addition to the feed-forward controller. The four feedback controllers includes (1) PID controller, (2) sliding-mode controller (SMC), (3) nonsingular terminal sliding-mode controller (NTSMC) and disturbance observer based controller using PSO. From the simulation and experimental results, the proposed method has the better performance than other methods.