頻率在遲滯現象的影響與其控制理論

Frequency effect on the hysteresis phenomenon and its control strategy

吳季儒(Chi-Ju Wu)

指導教授 ： 顏家鈺

國立臺灣大學/工學院/機械工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201600687

摘要

壓電制動器具備高位移解析度以及良好之動態響應性能，因此被廣泛應用於精密定位系統。然而，以壓電材料製成之驅動器在輸入電壓以及位移間含有遲滯所造成之非線性現象，造成控制上的困難，使其定位控制之精確度受到限制。
本論文將遲滯效應所造成的非線性現象與線性的機械系統做解耦，並針對遲滯造成的非線性消耗做補償，使遲滯對系統所造成的影響線性化，進而提升控制之精確度。依據文獻中提出的電荷控制架構，已知流經壓電制動器之電荷量與其伸長量呈線性關係，因此可藉串接於壓電制動器之電容量測電荷量進而得知遲滯所造成的電壓消耗，並以此建立遲滯補償器以利補償其非線性效應。本論文提出在不同操作頻率之下所產生不同的遲滯非線性現象之變動量，可由建構之靜態遲滯模型，以其變動量之倍數變化逼近，以簡易且快速之方式消除不同頻率下遲滯所產生之非線性影響。遲滯補償機制只用於遲滯現象線性化而不參與任何的位置控制，因此在設計上，位置控制器與遲滯補償兩者各自獨立。而位置控制器只需針對補償後剩餘之線性機械系統做控制設系，此法可大幅簡化控制演算之複雜度。壓電制動器之模型與分析、參數識別、Preisach模型之建構、將在本論文中介紹與討論。最後佐以不同控制頻率下之驗證結果。

關鍵字

壓電制動器 ； 遲滯補償 ； 遲滯模型

並列摘要

With high resolution and high dynamics response, piezo-actuator is widely used in precision position control system. However, there is nonlinear effect caused by hysteresis phenomenon between input voltage and displacement of the piezo-actuator which increase the difficulty for control, thus degrades the precision of control result. In this thesis, the nonlinearity caused by hysteresis phenomenon is decoupled with the linear mechanic system. And hysteresis compensation is implemented to linearize the hysteresis phenomenon for the sake of enhancing the control performance.Referring to the charge control structure proposed by L.S. Chen et al., it is shown that the relationship between charge flowing through the piezo-actuator and its elongation is linear. Therefore, by measuring the charge flowing through the piezo-actuator, the voltage consumption caused by the hysteresis can be obtained and the hysteresis compensator can be built to compensate the nonlinear effect. It is asserted that in this thesis that the differences of the hysteresis caused by different operating frequencies can be compensated by modifying the differences of the static hysteresis model. By this simple and fast method, the nonlinearity caused by the hysteresis phenomenon under different frequencies can be eliminated. The hysteresis compensation is only used for hysteresis linearization but not for position control. Therefore, the designs of tracking controller and hysteresis compensator are independent. While designing the tracking controller, the system can be regarded as a linear mechanic system after being compensated. By doing this, the complexity of control algorism can be reduced. For validity, a series of experiments under several frequencies are implemented in this thesis.

並列關鍵字

piezo-actuator ； hysteresis compensation ； hysteresis model

參考文獻

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