以快速開關閥實現單軸主動式氣壓隔振系統定位控制之研究

Abstract

本文旨在發展主動式氣壓隔振系統之定位控制，以創新之並聯式雙開關閥結合PWM控制訊號，控制氣壓隔振系統，實現定位控制及軌跡追蹤控制，同時，氣壓快速開關閥具價廉之優勢，而本文使用軟體實現脈波寬度調變方式控制電磁開關閥之開啟及關閉時間，如此可以不用透過硬體電路實現脈波寬度調變，在降低成本同時也可以達到控制精度的要求，藉由電磁開關閥快速的切換，形成間歇性流體，並藉由調整責任比來獲得平均性流體的輸出效果，以達到控制氣體流量之效果，並達到全數位訊號之控制系統。 本文首先建立氣壓隔振平台非線性數學模式，以MATLAB軟體進行系統動態模擬，完成開迴路之模型後，再結合具H infinity 追蹤性能之以函數近似法為基礎適應性滑動控制（FSB-ASMC+H infinity , Fourier series-based Adaptive Sliding Mode Control with H infinity tracking performance）設計控制器形成閉迴路的控制，而本實驗系統採用並聯式雙快速開關閥來控制氣壓隔振平台達成主動式控制，當氣壓隔振系統到達穩態後，容許誤差小於目標值後即可藉由快速開關閥關閉氣壓源，以防止因使用單快速開關閥控制，在穩態之後會造成持續快速切換的疑慮。

Position control of the single-axis active pneumatic isolation system is realized on this research. Innovating parallel dual-on/off valves with PWM control signal is implemented to control pneumatic isolation system for positioning and trajectory tracking control and then the pneumatic high speed on/off valves have the advantages of low cost. In this study, we use software to realize PWM technique to control on/off valves’ open and close time. Therefore, we do not have the hardware circuit to implement pulse width modulation and not only cost down but also reach control precision of demand. Intermittence fluid is formed by changing of high speed on/off valves and performance of average fluid is obtained by adjusting duty cycle, so as to achieve the effect of gas flow control, and to achieve all digital signal of the control system. In the first place, the non-linear mathematical model of vibration isolation platform is founded. The dynamic system is simulated by MATLAB. After open-loop model is completed, we combine this model with Fourier series-based Adaptive Sliding Mode Control with H infinity tracking performance to design controller to form a close-loop control. In this study, the pneumatic isolation platform is controlled by parallel dual-on/off valves to achieve active control. When the pneumatic isolation system is achieving steady-state and the allowable error is smaller than the demand, air source is shut by parallel dual-on/off valves. The continuous high change is prevented by using a single on/off valve after steady-state.