Optimal selection of process controller for a cascade control system using analytical hierarchy process

Abstract

Selection of Process controller is a onerous task in process industries. This paper narrowly tailors on usage of Analytical Hierarchy Process (AHP), to select the appropriate controller for a Real time cascade control system. The work starts with the identification of imperative enablers for selecting the controller with the help of experts from the process industries such as CPCL, CIPLA, PRICOL and NITC IPA lab. The AHP hierarchy tree was developed for selecting optimal controllers. Finally, questionnaire was issued to those experts for fixing the levels 2282 S. Muthukumaran et al. of scale ranging from 1-9 scale for performing the pair-wise comparison. The result of AHP has been successfully verified with the real time system software namely process analyzer. Process Analyser in control system is used to simulate the performance characteristics of Cascade control system that numerically justifies the result obtained through AHP. The empirical advantage of AHP is, it's a pure hierarchical approach for making a pair wise comparison between the criteria, sub criteria and alternatives for selecting a optimal controller in the Integrated Level-flow cascade control system.