基於預測干擾觀測器之控制方法於時間延遲系統

Abstract

本論文主要目的是將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波干擾，也能處理週期性干擾。同時也運用這項優點分別處理單輸入單輸出不穩定具非極小相位的延遲系統以及雙輸入雙輸出穩定的延遲系統。本論文所提的二種架構都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，也針對這二種架構，分析內部穩定度和強健穩定度。在模擬部份,利用不同例子比較針對三種不同干擾的抑制能力以及討論當系統有不定量存在時的強健度。

The purpose of this thesis is to use the design of the predictive disturbance observer for a class of delayed systems. 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. This advantage is applied to SISO (single-input-single-output) unstable non-minimum phase delayed systems and TITO (two-input-two-output) stable delayed systems. Both proposed schemes have two degree of freedom in designing controllers for setpoint tracking and disturbance rejection respectively. Internal stability and robustness of the proposed closed-loop system are analyzed. Performances are compared via several examples in the case of nominal model and perturbed model, subjected to step, ramp and periodic disturbances.