Adaptive multi-loop fractional order PID controller tuning using Bat colony optimization for Quadruple Tank process

Abstract

Quadruple Tank process is a multi-input-multi-output process. Mathematical modeling of the MIMO process is computed. State space model is computed from the mathematical model and is converted into transfer function matrices. Fourth order transfer function is approximated into first order plus dead time. Relative Gain Array (RGA) is computed for pairing the input and output. Steady state gain matrix is used for determining illness of MIMO system. Singular value decomposition technique is used to determine condition number to avoid sensitivity problem which arises due to small change of process output. In proposed method, multiloop centralized fractional order PID controller is designed for minimum phase Quadruple Tank process. Simulation studies show the likelihood of the proposed method for the computational analysis of the nonlinear minimum phase interacting process. The experimental results indicate that the developed control schemes work well under servo, regulatory and servo-regulatory conditions.