具震動抑制之QFT同步運動控制器設計與實現

Abstract

本研究考慮同動平台於高速同步運動下，如龍門铣床機，因系統不穩定發生震動之現象與平台未知擾動的影響下，導致平台精度下降及雙軸間同步誤差過大等問題。本論文導入交叉耦控制器(cross-coupled control, CCC)架構，並以量化回授理論(quantitative feedback theory, QFT)設計具震動抑制之穩健控制器，使同動平台高速運行下，精度大幅改善，另外，加入數位式擾動觀測器(digital disturbance observer, DDOB)，估測出外部擾動量進行補償。 研究結果顯示，加入數位式擾動觀測器後，成功地將未知擾動估測出來，並加以補償，使未知擾動對於平台的影響明顯改善。另外，使用交叉耦合控制器架構並結合量化回授理論設計具震動抑制之穩健控制器，成功地將雙軸同步誤差減小，且具有極高的穩定性，並於高速同步實驗下，平均同步誤差有效值13.36 ，大幅改善至1.65 。在循圓實驗下，獨立控制架構之平均輪廓誤差有效值為36.99 ，加入穩健交叉耦合控制器後，平均輪廓誤差有效值改善至3.12 。最後，本論文設計一套監控系統，當機台操作於高速或負載變化下，使用者可隨時監控機台，並適時加入控制器進行補償，使機台保持運行於高精密之精度。

This research considers applications on synchronous motion platforms under high-speed motion commands. Because a synchronous motion system easily becomes unstable due to the mismatched motion between two axes with jam, minimizing synchronization error during high-speed motion thus becomes critical. This thesis adopts both CCC (cross-coupled control) and QFT (quantitative feedback theory) for vibration suppression of the 3-axis Toyo motion platform. By applying the DDOB (digital disturbance observer) and the QFT controller designed with a notch filter and the lag compensator, motion vibration is thus effectively suppressed and synchronization error is also significantly reduced. Experimental results also indicate that the synchronization error is reduced from 13.36 to 1.65 , and the contouring error is also reduced from 36.99 to 3.12 . Finally, a monitoring system for the motion accuracy was developed to maintain platform motion precision of the platform even under high-speed operation.