Applet을 실행할 수 없는 경우에는 Java Run-time Environment(JRE)을 설치하십시오. http://java.com/download/
보안설정으로 차단된 응용프로그램과 같은 문제가 발생할 경우에는 Java 제어판의 보안 레벨 설정 을 참조하시기 바랍니다.
예외사항 사이트 에 https://www.cheric.org를 추가한 후 브라우저를 모두 닫고 다시 시작하면 Applet을 사용하실 수 있습니다.
PROCESS CONTROL APPLET SERIES IX
OVERVIEW OF PID CONTROLLER
The Importance of Process Control
In recent years the performance requirements for process plants have become increasingly difficult to satisfy. Stronger competition,tougher environmental and safety regualtions, and rapidly changing economic conditions have been key factors in the tightening of plant product quality specifications. A furher competition is that modern processes have become more difficult to operate because of the trend toward larger, more highly integrated plants with smaller surge capacities between the various processing units. Such plants give the operators little opportunity to prevent upsets from propagating from one unit to other interconnected units. In view of the increased emphasis placed on safe, efficient plant operation, it is only natural that the subject of process control has become increasingly important in recent years. In fact, without process control it would not be possible to operate most modern processes safely and profitably, while satisfying plant quality standards. [Seborg et. al., Process Dynamics and Control]
Objectives of This Applet
This applet is designed to illustrate the followings :
- - Elements of a process control system
- - Open-loop response of a process
- - Manual and automatic control
- - The basic function of PID controller
- - The options of PID controller
- - The effects of controller parameters on closed-loop Response
This applet consists of 5 parts. The horizontal thin panels on top and bottom are the title panel and status panel, respectively. The title panel is permanent one and the status panel is changing depending on the situation to give the explanation to users. In the Middle, there are three panels. The leftmost panel shows the process and instrumentation. The middle panel shows the response of each variable and controls the run of this applet. The rightmost panel shows the PID controller and its option. In this help, only these three panels will be described.
Process Panel
If the dots in the process inlet/outlet lines is pressed, the instrumentation will show. By clicking the instrumentation it will be hidden. Only for the inlet stream, if the display is clicked, the adjustment panel will be shown and the reading will be increased or decreased by clicking the triangle. If the green dot in the middle is pressed an arbitrary number can be type in the top of the Controller Panel.
Graph Panel
In the lower left corner, the thumbtack figure with freeze label will freeze or release the current plot. If it is freezed, next plots will be drawn on top of previous plots. In the middle, there are 4 preset-run options and a 'run with present condition' option. After selecting one option, by pressing 'RUN/PAUSE' button, the simulation will be proceeded. At the bottom, two listboxes will decide the speed of simulation and the difficulties of the process nature.
Controller Panel
The setpoint (SP) and manipulated variable (MV) can directly be changed by dragging the indicators in the controller faceplate. The AUTO/MAN mode can be toggled by clicking the area. By clicking the pull tab on the side of the faceplate, the parameter plate will be toggled to be shown. The controller parameters (controller gain, inverse of integral time, and derivative time) can be increased or decreased by a predefined amount by pressing triangles. If the green dot in the middle is pressed an arbitrary number can be type in the top of the Controller Panel. By pressing relevant portion the options can be toggled.
Multi-Loop Distillation Column Control (Java Applet will help you interactively.)
Will be given by the instructor
