Comparative study between Fractional Order $PI^{\lambda}D^{\mu}$ and Integer Order PID Controller: A case study of coupled conical tank system with actuator faults

Abstract

This article presents a fractional-order PID (FOPID) controller scheme for a coupled conical tank level control (CCTLC) system. The coupled conical tank level control systems are having strong dynamic and nonlinearity characteristics; further, these systems come across frequent faulty conditions. Hence, for the smooth and trouble-free operation of the coupled conical tank level control system, an effective control mechanism could be adopted. The objective of this work is to design an efficient fractional-order PID control scheme to ensure a robust performance with respect to actuator fault in regulatory and servo performance. The mathematical model of a coupled conical tank level control system is developed to validate the effectiveness of the proposed control scheme. Furthermore, FOPID parameters optimized by minimizing the ISE index and integer-order PID (IOPID) controller parameters are found using zigler nichols (ZN) controller tuning method. Simulation studies are carried out in nonlinear coupled conical tank level control system under abrupt and incipient nature of actuator faults using fractional-order PID (FOPID) controller. The results demonstrate the usefulness of the proposed strategy and confirm the performance improvement for the coupled conical tank level control system subject to actuator fault. To highlight the advantages of the proposed scheme a comparative study with conventional IOPID and FOPID control schemes is made.