文档介绍：Revisiting the Ziegler–Nichols step response method for PID .?Astr€om, T. H€agglund*Department of Automatic Control, Lund Institute of Technology, . Box 118, SE-221 00 Lund, SwedenAbstractThe Ziegler–Nichols step response method is based on the idea of tuning controllers based on simple features of the step re-sponse. In this paper this idea is investigated from the point of view of robust loop shaping. The results are: insight into theproperties of PI and PID control and simple tuning rules that give robust performance for processes with essentially monotone stepresponses.?2004 Elsevier Ltd. All rights :PID control; Design; Tuning; Optimization; Process control1. IntroductionIn spite of all the advances in control over the past 50years the PID controller is still the mon con-troller, see [1]. Even if more sophisticated control lawsare used it mon practice to have an hierarchicalstructure with PID control at the lowest level, see [2–5].A survey of more than 11,000 controllers in the re?ning,chemicals, and pulp and paper industries showed that97% of regulatory controllers had the PID structure, see[5]. Embedded systems are also a growing area of PIDcontrol, see [6]. Because of the widespread use of PIDcontrol it is highly desirable to have e?cient manual andautomatic methods of tuning the controllers. A goodinsight into PID tuning is also useful in developing moreschemes for automatic tuning and loop all books on process control have achapter on tuning of PID controllers, see . [7–16]. Alarge number of papers have also appeared, see . [17–29].The Ziegler–Nichols rules for tuning PID controllerhave been very in?uential [30]. The rules do, however,have severe drawbacks, they use insu?cient processinformation and the design criterion gives closed loopsystems with poor robustness [1]. Ziegler and Nicholspresented two methods, a step response method and afrequency response method. In this paper we willinvestigate