二層觀念應用於離散順滑模態控制

Abstract

傳統的順滑模態控制通常需要知道不確定性干擾訊號的上限，以確保系統 的穩健性；然而在實際應用上卻往往無法得知其上限。在本論文中，首先 引入二層觀念的控制架構，再根據此架構進而提出新的離散順滑模態控制 器。在新的控制器作用之下，不僅可藉由干擾訊號的變化率來取代對干擾 訊號上限的估測，亦可憑藉參數 a 的調整來控制逼近順滑平面的速度。 除此之外，對於系統矩陣具有不確定性訊號的情形，本論文亦就其為非時 變與時變，分別提出不同的控制器來加以討論。另外，再分析 Wang 所提 的控制器並與之比較，以凸顯所提控制器的優越性。最後再針對系統穩定 性的問題，做更深入且完整的探討。 The conventional sliding-mode control technique requires knowledge of the upperbounds of disturbances to assure robustness; however, it is hard to obtain in practice. In this thesis, the two-layer concept is introduced and a new simple discrete-time sliding-mode controller is presented. Using the proposed method, we not only avoid measuring the upperbounds of disturbances but also can adjust desirable reaching rate to the hyperplane. In addition, the effect caused by disturbances on the system matrix is discussed with different methods according to the system matrix is time-invariant or time-varying. On the other hand, in order to show the advantages of the proposed control strategy, we analyze and compare with Wang's controller. Finally, we point out the bug of Wang's controller and improve it.