A Study on Hysteresis Modeling and Identification for Piezo-Driven Precision Positioning

[[abstract]]摘要 產品愈來愈精密微小，其構裝、組裝、生產設備要求更為精準，但傳統機械定位方式因庫侖摩擦力等不良因素存在，不易達到更精準定位。壓電晶體因其位移解析度高，剛性強，近年已成為微奈米高精密定位控制上一個很重要基本的驅動元件。 唯壓電晶體存在遲滯、飽和、潛變等非線性現象，在開迴路控制上會產生顯著之誤差，在閉迴路控制中亦會顯著影響系統響應頻寬及穩定性，故有必要對壓電晶體的特性做精確而簡易之建模，從而藉此可對壓電晶體進行反非線性補償，而獲得更佳之控制效能。 本研究主要即針對壓電晶體之非線性特性提出一個有別於傳統各種複雜遲滯模型而簡易之等效電路模型，此模型僅為電阻電容之串並接電路，其中僅電阻為非線性元件。此外本研究並針對此模型提出其參數鑑別方法，依此模型及其鑑別之參數可精準模擬壓電晶體之非線性行為從而加以控制補償。[[abstract]]Abstract Micro-nano precision posititoning has been required in the varions automated machinery. For such high precision positioning, piezo-actuator is most commonly used due to its merits of high resolution, and high stiffness. However, piezo is not an ideal actuator. It exhibits some nonlinearities such as hysteresis, saturation, and creep. These nonlinearities will cause significant inaccuracy and/or stability problem in an open/closed loop control system. An accurate and simple model for modeling these nonlinearities is then required for better control. In this paper, such a model with simple RC equivalent circuit was propesed. Meanwhile, an algorithm for the parameter identification of the model was illustrated as well. With this proposed model and the identified parameters, the nonlinearities of the piezo actuator can be accurately simulated and compensated