應用模糊PID之PLC控制液壓伺服系統

A PLC-Based Fuzzy PID Controlled Hydraulic Servo System

陳俊銘(Chun-Ming Chen)

指導教授 ： 顏炳郎

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2005年)

摘要

液壓系統存在著高度非線性特性，系統的參數會隨著時間及操作環境而改變，傳統的PID控制對於線性系統而言，雖然可以使整個控制系統達到要求動態響應，加上其結構簡單、穩定性好，因而是目前工業界最為廣泛使用的一種控制模式，但是對於高度非線性的液壓系統而言，卻無法滿足控制精度的需求。因此，本文提出一非線性的控制模式以控制液壓伺服閥，進行液壓伺服精密定位之控制。 本文主要結合PID與模糊控制理論，以模糊PID的觀念與想法，配合專家的調整經驗，動態的調整PID參數以達到最佳的控制結果。雖然目前有許多文獻提出各種控制策略，應用於液壓缸的伺服定位及壓力控制上，例如模糊控制、自調適適應控制、自調式PID控制、及強健控制等，但在控制器的實現方面，均以電腦或是PC-Base控制器加上伺服軸卡的控制架構為主，本文是以工業界最熟悉之可程式邏輯控制器PLC為基本架構，來實現所提出的模糊PID控制策略，融合業界長期累積的調整經驗法則，使本文所發展之控制器架構，更具產業的實用性，並可提昇國內生產產業機械的公司，在伺服控制領域的核心技術。

關鍵字

液壓伺服 ； PLC控制器 ； 模糊PID ； 模糊控制 ； 精密定位

並列摘要

High nonlinearity and time variation are very common in hydraulic servo systems. The system parameters are varying from time to time and due to different operation conditions. Demands for wide range of operation conditions, such as different positioning range, make a linearization model, linearized around a single operation point, inaccurate to describe the system dynamic behavior. Therefore, a traditional PID controller, which used to work well in a linear system, will not be able to work satisfactorily for the highly nonlinear system with time varying system parameters. In order to counter the problem, we proposed a nonlinear controller of an architecture of fuzzy PID, to dynamically tune the PID gains so that an optimal performance outcome can be obtained. In the past, there are plenty of advanced control strategies have been proposed in literatures to solve the hydraulic servo system, such as fuzzy controller, self-tuning adaptive controller, self-tuning PID controller and robust controller etc. However, most of them were using the PC-based framework. At the time being, PLC is the most popular controller used for manufacturing machines. In this paper, a framework of using PLC as the controller unit, combining the fuzzy PID control strategy, will provide a very high potential solution in practice for the industry of hydraulic servo system applications. This technology will also help domestic companies to build up their own core technology in servo control aspects.

並列關鍵字

Hydraulic servo system ； PLC ； PID control ； Fuzzy PID control ； Fuzzy control ； Precise Positioning System

參考文獻

[11] 劉源良，模型參考自適應類神經網路之電液伺服控制，博士論文，中原大學機械工程學系，中華民國九十二年。

[26] 董義雄，直流無刷馬達之適應性模糊滑動模式位置控制，碩士論文，中原大學電機工程學系，中華民國九十二年。

[4] 陳秉昌，低速高精度液壓系統伺服位置控制之研究，碩士論文，國立成功大學機械工程學系，中華民國九十二年。

[6] A. Isidori, ”Nonlinear Control Systems”, Springer Verlag, Third Edition, 1996.

[8] RUI LIU B.Engr., Nonlinear Control Of Electro-Hydraulic Servosystems：Theory And Experiment, Tsinghua University,1994.