高速線性馬達工具機之位置迴路控制策略研究

RESEARCH ON TRACKING CONTROL STRATEGY FOR HIGH SPEED MACHINE TOOL WITH LINEAR MOTOR

謝政誼(Cheng-Yi Hsieh)

指導教授 ： 吳昌暉

元智大學/工程學院/機械工程學系/碩士(2003年)

摘要

本研究論文以線性馬達四軸臥式銑床工具機為主題，實際進行線性馬達應用於工具機系統的電控整合且以實驗法建立系統低階動態模型，最後分析系統實際的物理現象和調整系統控制參數。首先由工具機的機械結構推導機械系統的動態方程式與轉移函數，然後進行共振現象的模擬與分析，利用傅立葉轉換將步階響應轉換至頻率響應進行系統鑑別，並由頻域響應圖確認因機械結構撓性所引起的與運動方向平行之共振現象。在系統結構共振70Hz與速度迴路只能提供5階的控制器的架構下，經參數調整後目前系統速度迴路頻寬最大可達20Hz、最高速度可達70m/min。而在位置迴路控制方面，模擬分析比較不同控制方法對系統位置精度的影響，並針對系統目前的循圓精度性能，提出外加相位領先落後控制器的方法以提升位置迴路的循跡精度，並且實際製作類比電路實際進行線上閉路測試並與未加入控制器之軌跡比較，經實驗證明在未實際切削工件的循圓半徑50mm、0.2Hz的條件下可改善約10倍的原有切削精度。

關鍵字

定位控制 ； 動態循跡控制 ； 系統鑑別 ； 循跡誤差

並列摘要

In this thesis, we focus on the physical analysis and position control of linear motors applied to the machine tool. In the beginning, we derive the dynamic equations and transfer function from the free body diagram of the machine tool structure. And through the simulation of the transfer function, we find that the frequency of vibration corresponds to the physical phenomenon which we observe in the step response experiment. Besides, we use discrete Fourier transform (DFT) to transform an ordered sequence of data samples in the step experiment from the time domain into the frequency domain. Consequently, we can conclude that the flexibility of the mechanical structure gives rise to the vibration. In position loop, we analyze several control algorithms and compare what advantage and disadvantage each has. At last, we propose an additional analog electronic lead-lag circuit to improve the contour error. After experiments, it validates that the lead-lag controller can improve about ten times tracking error.

並列關鍵字

Position control ； Dynamic tracking control ； System identification ； Tracking error

參考文獻

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