基於預測干擾觀測器之控制方法於雙輸入雙輸出(TITO)不穩定時間延遲系統

Abstract

本論文主要目的是利用不穩定雙輸入雙輸出系統解耦控制方法，將雙輸入雙輸出程序轉移函數矩陣簡化為SISO系統，增加內迴路使系統穩定，並利用預測干擾觀測器應用於時間延遲系統。由於時間延遲廣泛地存在各種控制系統中，針對時間延遲有很多種補償方式，但是大多數的時間延遲補償方法並不能有效的抑制干擾，特別是週期性干擾。針對這項缺點，本論文基於預測控制的概念，利用干擾的特性，消除時間延遲的影響，改善傳統干擾觀測器不能立即補償干擾的缺點。因此本文所提的架構，不僅能抑制步階和斜坡干擾，也能處理週期性干擾。同時也運用本論文提出的不穩定系統解耦控制方法，處理雙輸入雙輸出不穩定的延遲系統，簡化控制器設計的複雜度。建議的架構中有二個自由度的控制器設計，所以能夠分別設計針對追蹤設定點以及抑制干擾的控制器。除此之外，也針對此架構，分析強健穩定性。在模擬部份,利用輸出時間延遲不穩定系統與輸入輸出時間延遲不穩定系統，針對三種不同干擾的抑制能力及強健穩定性加以討論。在實驗的部份，以倒單擺為實驗機台，彰顯PDOB架構抑制步階與弦波干擾的能力。

The purpose of this thesis is to use the decoupling control method for a class of TITO (two-input-two-output) unstable delayed systems. By the way of decoupling procedure, the TITO system is simplified to a SISO system. The unstable system can be stabilized by using the inner loop structure. Since time delay exists in many industrial processes, there are many time delay compensation methods. However most of the compensation methods can not attenuate disturbance effectively, especially for periodic disturbances. In this thesis, the concept of predictive control is utilized based on the characteristic of deterministic disturbances to eliminate time delay effect, hence the proposed design achieves better disturbance rejection which not only applies to step and ramp disturbances but also to periodic disturbances as well. Furthermore, the decoupling control method is used to solve the dead-time problem with the TITO unstable system, and the method simplifies complexity of the controller design. Both proposed schemes have two degree of freedom in designing controllers for set-point tracking and disturbance rejection respectively. Robustness of the proposed closed-loop system is analyzed. Performances are compared via two examples in the case of output delay and input/output delay, subjected to step, ramp and periodic disturbances. Finally, the inverted pendulum as an experimental platform manifests the ability of disturbances rejection for the predictive disturbance observer (PDOB) architecture.