控制系統下干擾消除方法之研究

Studied on Disturbance Rejection Methods of Control Systems

陳益德(Yi-De Chen)

指導教授 ： 董必正

國立中央大學/工學院/機械工程學系/博士(2008年)

摘要

外力干擾發生在許多控制工程的應用場合中，本篇論文提出幾種主動式干擾消除的方法來降低控制系統中週期或非週期干擾所造成的影響。首先討論幾種常見的解決週期干擾的方法，並提出一個改良的凹口濾波器來消除線性系統中的週期干擾，使用此方法可快速的降低外力干擾的影響，而外力干擾的週期量測誤差範圍及降低干擾影響的效果可藉由調整凹口濾波器的參數來做設計。其次針對未知頻率的週期或非週期干擾，提出兩種具強健性的干擾消除方案，第一種方案是結合滑動控制與提出的新的干擾消除控制器，而第二種則是利用修改過的滑動控制器與時間延遲控制作結合，不同於以往常見的方法，兩種方案都不需要對干擾的頻率作估測，並可在不確定性的穩定系統及不穩定系統中降低週期或非週期干擾的影響，在第一種方案中所提出的干擾消除控制器亦可進一步地與Astrom’s Smith預測器及灰色預測方法作結合，於線性延遲系統中降低週期外力干擾的影響。

關鍵字

干擾消除 ； 內部模型原理 ； 適應性前餽消除 ； 滑動控制 ； 時間延遲控制 ； 灰色預測 ； 史密斯預測器

並列摘要

Disturbance problems can occur in many different engineering control applications. This dissertation presents some active disturbance rejection methods to reduce influences of periodic or non-periodic unknown disturbances in control systems. First, several common methods of periodic disturbances rejection are discussed. A modified notch filter is proposed to reject the periodic disturbance in the linear control system. The use of the notch controller can lead to a quick reduction of the influence of an excitation force. The tolerant error range of the corresponding frequency and the disturbance reduction effect can be designed by adjusting parameters of the modified notch filter. Next we propose two robust disturbance rejection schemes for dealing with disturbances of unknown frequencies. One of disturbance rejection schemes is a novel disturbance reduction controller with a sliding mode controller. Another scheme is a modified sliding mode controller with time delay control. Unlike many other approaches, both the schemes proposed here do not require the disturbance frequencies of the separate harmonics to be estimated and can reduce both periodic and non-periodic unknown disturbances with uncertainties in stable systems or in unstable systems. The proposed controller in one of the schemes can be extended to be combined with Astrom’s modified Smith predictor and a grey predictor for periodic disturbance reduction in linear delay systems.

並列關鍵字

disturbance rejection ； internal mode principle ； adaptive feedforward cancellation ； sliding mode control ； grey prediction ； time delay control ； smith predictor

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