- 學位論文
時變結構之適應性控制研究
Application of Adaptive Control on Time-Varying Structure System
摘要
由於大自然界中的強風與地震，往往會對土木結構物帶來安全性的威脅，為了增加其受震時的抗震能力，結構控制技術因此得以發展。結構控制從形式可分成被動控制、半主動控制、主動控制；其中半主動與主動控制可將該隔震或減震元件視為一種控制元件，經由一方主控端對於該元件輸入命令以及外部能源以調整控制元件的力量，並進而改善結構物的動力特性。由於其控制端之輸入命令來自於控制理論的運算，故控制理論的發展成為結構控制的主要核心。 然而，在控制理論中被廣泛使用的LQR理論在由於其需要結構之系統資訊作為運算控制力的基本條件，因此當結構物為一時變系統例如產生破壞或老化而造成勁度折減時，LQR所計算的控制力會無法對受控體產生有效的控制效果。故本文嘗試結合系統識別之技術，使時變性結構的資訊能被即時更新並重新設計適當的控制器以增加傳統控制器的可適性與控制能力。 本研究針對時變性結構設計了一個有別以往最佳化控制方法的可適性控制機制，目的是為了要提升最佳化控制在時變結構受外力擾動下的控制效益，首先在第二章介紹LQR控制法，並透過雙自由度的連棟結構物控制實驗證明該理論之可靠性。接著介紹第三章的系統識別理論：子空間識別法，利用該方法能有效地識別出系統矩陣，進而得到頻率與勁度資訊。最後將上述兩者進行結合並設計了兩種具適應性的最佳化控制方法，其方法分別為補償器控制法與回饋增益矩陣調整法，前者概念為利用系統回饋的勁度折減資訊將原本輸出給系統的控制力額外施加一個能夠補償受損系統的補償力，使折減系統能夠運作地像是未折減系統之反應。後者則針對不同折減程度之系統求其理想的回饋增益矩陣並透過識別出的結構資訊調整為理想的回饋增益矩陣進行控制。為了驗證該時變方法的應用性，我們使用Simulink對一個一樓勁度折減之三自由度結構進行模擬，並以半主動控制器之數值模型進行控制。透過模擬的結果可發現，透過子空間識別法回傳的系統資訊，勁度補償器之額外補償力與增益矩陣調整器之調整後的控制力均可對勁度折減系統之位移反應達到有效的控制效果。
並列摘要
For improving the resistance of the structure to against the earthquake, the development of structural control becomes an important issue in civil engineering. Structural control can be classified into three types: Passive control, Active control and Semi-active control. The definition of Active control and Semi-active control is using the device installed in the structure which could adjust the behavior by input order to change the dynamic characteristic of the structure. Therefore, applying an ideal control algorithm to compute the input order is the core of the structural control technique. LQR control is one of the significant control algorithms. The design of the LQR controller is depend on the system’s information. However the control effeteness will be poor when the system is time-varying. The purpose of this research is trying to improve the adaptive ability of the LQR controller by combining the system identification technique. And the controller could update the system information of the time-varying system to reform the original LQR controller’s effeteness. The research designed an adaptive controller which is different from the original LQR controller for time-varying system. First in Chapter 2 will introduce the LQR algorithm and to verify the control superiority by a 2 DOFs connected structure control experiment. Then in Chapter 3 we will mention about the system identification algorithm: Subspace Identification which could identify the system information including the natural frequencies and stiffness matrix precisely. In Chapter 4 we combined these two algorithms and design two methods to create the adaptive controller. One of the methods is System Compensator which is used to compensate the reduction of the system’s stiffness by increasing the control force and make the time-varying system behaves like a healthy system. Another method is Gain Switcher which will switch an optimal control gain corresponded to the level of stiffness reduction of the time-varying system. Finally, we used Simulink to simulate the time-varying systems responses under these two adaptive control methods with the mathematic model of MR damper to verify the effeteness. By updating the system’s information using subspace identification, the two adaptive controllers reduced the displacement responses ideally.
參考文獻
延伸閱讀
- 古紹武（2016）。連續時變系統之辨識與其控制性能評估〔碩士論文，中原大學〕。華藝線上圖書館。https://doi.org/10.6840/cycu201600817
- 鍾立來、陳正宗（2014）。參數變異法於結構動力學之應用。結構工程，29(1)，107-113。https://doi.org/10.6849/SE.201403_29(1).0006
- Chuang, Y. C. (2006). 適應性質群最佳化演算法應用於動態環境問題之研究 [master's thesis, Yuan Ze University]. Airiti Library. https://doi.org/10.6838/YZU.2006.00208
- 王永建（2009）。Adaptive Model-Following Control of the Hydraulic Servomechanism〔碩士論文，崑山科技大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0025-2408200916341100
- Chiang, M. L. (2010). Adaptive Control of Switched Systems with Unknown Parameters: Analysis and Design [doctoral dissertation, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2010.00859