以壓力閥控制液靜壓軸承等膜厚之探討

An Investigation in Constant Film Thickness of Hydrostatic Bearing by Using Pressure Control Valves

彭聖翔(Sheng-Xiang Peng)

指導教授 ： 康淵 ； 康淵

中原大學/工學院/機械工程研究所/碩士(2018年)

https://doi.org/10.6840/cycu201800833

摘要

使用節流或定流量補償液靜壓軸承之油腔壓力，能讓液靜壓軸承有比其他類型軸承更佳的負載能力，與使用其他類型的軸承支撐工作台一樣，靜壓軸承隨著負載的變化而不斷移動。本文涉及固定液靜壓油膜厚度的壓力控制，只要讓油膜厚度控制為等膜厚，工作台可在負載變化時保持穩定且不會發生位移變化。
本文目標為液靜壓軸承閉式工作台之油膜厚度保持相同厚度，並探討控制壓力閥之壓力控制解決膜厚隨負荷改變造成油膜變化的問題，以液靜壓軸承閉式工作台上的供油壓力、位移計訊號以及流量訊號作為回饋訊號，並以壓力補償控制液靜壓工作台建立控制迴路。本文以壓力感測器及位移感測計回饋訊號，再計算出壓力差值以及位移差值進行壓力補償，以達到等膜厚之目標值。
在等膜厚壓力補償系統中，需透過PID控制器系統以及類神經網路訓練的搭配使用才能夠達到暫態快速收斂、穩態能夠達到精準且穩定的補償系統。把液靜壓軸承壓力現行補償方法，作了控制法則的演算，提出數學模型，以壓力控制閥的等膜厚控制進行實驗驗證。
透過實驗找出最佳的類神經訓練參數以及PID控制器之參數值，可從調整係數當中找出最佳之類神經網路及PID控制器參數。本研究算法的PID控制器已能達成次微米的穩態精度並通過數值模擬和實驗測量驗證此演算法。

關鍵字

液靜壓軸承 ； 膜厚控制 ； 等膜厚

並列摘要

Restriction or constant flow is utilized to compensate recess pressures of a hydrostatic bearing which can be highest load capacity than any other type bearing, but not stiffness. Like to other type bearings supporting the worktable that is displaced continuously with changing load. This study concerns flow rate control for constant thickness of hydrostatic film. As long as film thickness is controlled to be constant, worktable can be kept stable without displacement when load is changing.
The objective of this study is to maintain the constant film thickness of the oil film thickness of the hydrostatic bearing closed table, and to discuss the pressure control of the pressure valve to solve the problem of film thickness change caused by the change of load, and to supply oil on the hydrostatic bearing closed workbench. The pressure, displacement meter signal and flow signal are used as feedback signals, and the control circuit is established by the pressure compensation control hydrostatic pressure table. In this paper, the pressure sensor and the displacement sensor are used to feedback the signal, and then the pressure difference and the displacement difference are calculated for pressure compensation to achieve the target value of the constant film thickness.
In the constant film thickness pressure compensation system, it is necessary to use the neural network training and the PID controller system to achieve a transient and fast convergence, and the steady state can achieve a precise and stable compensation system. The current compensation method of hydrostatic bearing pressure is made, and the calculation of the control law is made. The mathematical model is proposed and verified by the film thickness control of the pressure control valve.
The steady-state accuracy in few sub-micrometers can be achieved by Neueal Network and PID controller using the algorithm of this study, which have been verified by numerical simulation and measurement in experiments.

並列關鍵字

hydrostatic bearing ； film control ； constant thickness

參考文獻

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[4] Rowe W B 2012 Hydrostatic, Aerostatic and Hybrid Bearing Design (London: Butterworth-Heinemann) pp 83-113.

[5] Kang Y, Lee J L, Huang H C, Lin C Y, Lee H H, Peng D X and Huang C C 2011 Design for static stiffness of hydrostatic plain bearing:constant compensations Ind. Lubr. Tribol. 63 178-91.