Acidic control of a chemical plant implementing non linear controllers

Abstract

This research work concentrates on developing a non linear control technique using PID control, Fuzzy Logic controller and SMC (Sliding Mode Controller) for acidic control of a chemical plant. This control involves (Variable Structure Control) VSC control. The acidic control process includes a prototype model. This model has two inlets to the sample liquid. The two inlets supply acid and alkaline liquids into a Continuous Stirred Tank Reactor [CSTR]. Both the inflows are controlled in proper proportions, which help to maintain the desired pH of the system. The pH neutralization process is a non linear process; hence VSC serves as a better solution. One type of VSC is the Sliding Mode Control which is applied to this system. Apart from this VSC, both PID control and fuzzy control are incorporated on the same process and the results are furnished. SMC suffers a problem called chattering, but provides reliable results when compared to PID and Fuzzy Logic Controller. This research is done using LabVIEW Software, Hence all the control methods are implemented using the same. Laboratory Virtual Instrumentation Workbench is abbreviated as LabVIEW. The programming done with this software is applied to the prototype system and the results of the controllers are compared and it is found that SMC controller is better suited than PID and fuzzy controllers.