穩定、積分及不穩定程序之雙自由度PID控制器設計：直接由製程資料設計

Design of 2DoF PID Controllers Directly from Plant Data for Stable, Integrating, and Unstable Processes

傅恩平(En-Ping Fu)

指導教授 ： 鄭智成

國立臺北科技大學/工程學院/化學工程研究所/碩士(2013年)

摘要

PID控制器是化學程序工業中最為廣泛使用的控制器，因此文獻中有許多基於程序模式(model-based)之PID控制器設計方法的研究。而基於程序模式之PID控制器設計方法主要的缺點就是應用於高階程序動態時，由於不可避免的模式誤差導致控制器效能降低。因此，不需要憑藉程序模式，而直接以一組程序輸入與輸出資料來設計控制器的方法是具有高度應用價值的。
　　本研究提出一個直接由製程測試資料來進行雙自由度PID控制器設計的新方法，可應用於各類型程序，包括穩定、積分及不穩定程序。此方法的設計目標為找到一組PID控制器參數，使控制系統的動態行為儘可能的接近所指定的參考模式，該參考模式定義閉環路系統對於設定點追蹤或是干擾排除的動態應答，由於程序為未知，適當的參考模式乃透過簡單的一維最適化問題以及系統韌性的考量來決定。單一自由度PID控制器無法同時達到良好的設定點追蹤與干擾排除性能，因此本研究設計具有設定點權重之雙自由度PID控制器來改善設定點應答，比例與微分作用之設定點權重參數則是藉由使系統設定點應答儘可能跟隨所指定的參考軌跡而決定。模擬結果顯示，對於各類型程序，本研究所提出的PID控制器設計方法皆能達到優於其他基於程序模式設計方法之控制性能，具有廣泛的實用性。

關鍵字

程序控制 ； PID控制器 ； 積分程序 ； 不穩定程序 ； 雙自由度控制器

並列摘要

PID controllers are the most widely used controllers in the chemical process industries, and therefore various model-based PID design methods have been developed. A major drawback of the model-based methods is that their effectiveness would degrade for high-order process dynamics because of the inevitable modeling error. Consequently, it is an attractive alternative to design PID controllers directly based on a set of process input and output data without resorting to a process model.
　　This study proposes a novel method of two-degree-of-freedom (2DoF) PID controller design for stable, integrating, and unstable processes directly using the plant data available from plant test. The proposed method first derives the PID parameters so that the resulting control system behaves as closely as possible to the prescribed reference models. The references models can be defined to describe the desired closed-loop dynamics for either set-point tracking or disturbance rejection. A simple one-dimensional optimization problem is formulated to determine an appropriate reference model, with also the robustness consideration, for the controlled process. Satisfying good control performance for disturbance rejection and set-point tracking simultaneously is not possible by using a one-degree-of-freedom (1DoF) PID controller. Therefore, the 2DoF PID controller with set-point weighting is subsequently designed to improve the set-point response. The set-point weighting parameters for the proportional and derivative modes are obtained so that the set-point response follows a prescribed reference trajectory. Extensive simulation results show the superiority of the proposed method over existing (model-based) PID design methods for various types of process dynamics.

並列關鍵字

process control ； PID controller ； integrating process ； unstable process ； two-degree-of-freedom controller

參考文獻

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