液靜壓軸承之油壓系統進階控制

Advanced Control of Hydraulic System for Hydrostatic Bearings

莊鎧榤(Kai-Chien. Chuang)

指導教授 ： 宋震國 ； 杜佳穎

國立清華大學/工學院/動力機械工程學系/博士(2021年)

摘要

目前毛細管等被動式節流器廣泛的使用於液靜壓軸承，然而此種節流器無法有效地補償負載造成的供油壓力變化。本文提出另一種替代的方法，使用主動式比例壓力閥進行壓力控制來提高液靜壓軸承運行的精度，期在液靜壓軸承高速運作時，仍能藉由實時控制與監測系統，有效地、強健地補償節流器與液壓系統之壓力，維持軸承穩定運作達到液靜壓軸承預定之加工精度。
為了達到實時控制與監測的目標，本文先介紹液靜壓線性平台之運動方程式並介紹滑塊之靜態模型，得到滑塊之油膜承載力與剛性。接著介紹實驗設備，設明主動式液壓調控裝置的概念、液壓調控設備與即時控制設備的連接。
介紹完液靜壓線性平台理論與實驗設備後，接著介紹控制策略，在本研究中，採用雙重迴路控制策略，藉由內迴路策略初步控制油壓系統，再藉由外迴路控制方法，提升系統的響應速度並改善暫態反應。在實驗方面，先給定輸入電壓訊號，壓力傳感器量得壓力輸出訊號，將輸入與輸出數據轉入Matlab程式中，比較實驗輸出訊號與識別輸出訊號，得到系統識別之轉移函數。再結合供油設備與液壓軸承系統模型，並以dSPACE控制設備連接液壓軸承系統，即時讀取油壓系統之壓力等訊號，建立自動控制補償與監測設備。最後，實驗結果顯示所提出的主動控制架構有效地改善油壓的上升時間和追蹤精度。本文研究結果對未來的智能控制的發展和工具的製造提供一種可行的控制架構。

關鍵字

液靜壓軸承 ； 反模型控制 ； 模型匹配控制 ； 液壓系統 ； 節流器

並列摘要

Recent developments in precision manufacturing heighten the need of hydrostatic bearings for machine tools, because of the advantages of high stiffness, high precision, low friction and long service life, as compared with the traditional roller bearing systems. In literature, attention has been paid to the design of fixed-type restrictors such as capillaries for hydrostatic bearings. However, such passive flow restrictors could not effectively compensate for oil pressure variation as a result of loading changes. To seek an alternative for improving the operation precision of hydrostatic bearings, pressure control using active proportional valve is considered in this work. Four proportional valves are installed in the hydraulic system and controlled by advanced output feedback control with integral action and model matching techniques. Experimental studies on the actively-controlled hydrostatic system are performed. The results show that the rising time and tracking accuracy of the oil pressure are effectively improved by the proposed active control framework, thus sustaining the performance of hydraulic bearing. The success of this research offers a feasible control framework for the development of intelligent control and manufacture of machine tools in future work.

並列關鍵字

hydrostatic bearing ； model inverse control ； OFCIA ； model matching control ； hydraulic system ； restrictor

參考文獻

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