Design, Development and Applications of PC-based Process Control Trainer for Automation

摘要

Initially, Process Control was typically done in the analog domain using continuous-time signals with analog systems. However, as the complexity of the control function increased, it became very costly, and, at times, unfeasible to use only analog elements. The rapid evolution of digital computers caused a major shift to digital technologies, and led to the control action being done in the digital domain using discrete-time signals with digital systems. The main motive behind designing and developing the PC-Based Process Control Trainer (PCT) for automation is to have a system which is versatile, easy to use, interactive, intelligent, and quickly developed. Physical variables like temperature, fluid flow and levels at various points in the system are monitored and control action is provided to various heaters, stirrers, valves and pumps. One utilizes LABTECH's LT/CONTROL software package which reads the inputs from the standard data acquisition and control add-on cards. It performs various calculations as per the requirement and the results are used in the control strategy. It provides real-time data logging, data storage and real-time display control panel for the user interface with multiple display screens to view the system. The PCT is built, tested and found to work satisfactorily. About twenty experiments are set up and performed on it. These check various devices in the system, help in studying various types of control actions and automate the trainer for particular processes. The PCT has varied applications for automation. On the educational front, it can be used as a basic control laboratory. New experimental setups can be configured to study open loop and closed loop control systems for temperature, flow and level control. Automation of different processes with a choice of control actions can be done. From the industrial point of view, it provides an insight to industrial control; prototypes of process control systems can be built and used as a stepping stone to change the present manual or semi-automatic control to complete automation.