Frequency Domain Specifications Based Robust Decentralized PI/PID Control Algorithm for Benchmark Variable-Area Coupled Tank Systems

Abstract

A decentralized PI/PID controller based on the frequency domain analysis for two input two output (TITO) coupled tank systems is exploited in this paper. The fundamentals of the gain margin and phase margin are used to design the proposed PI/PID controller. The basic objective is to keep the tank at the predetermined level. To satisfy the design specifications, the control algorithm is implemented for decoupled subsystems by employing a decoupler. First-order plus dead time (FOPDT) models are obtained for the decoupled subsystems using the model-reduction technique. In addition, the control law is realized by considering the frequency domain analysis. Further, the robustness of the controller is verified by considering multiplicative input and output uncertainties. The proposed method is briefly contrasted with existing techniques. It is envisaged that the proposed control algorithm exhibits better servo and regulatory responses compared to the existing techniques.

Design of a decentralized control law for variable area coupled tank systems using H∞ complimentary sensitivity function

“…The tank levels that need to be regulated are denoted by l 1 and l 2 , respectively. The transfer function of the QTS as reported in [4] is given by…”

“…Figure 9 illustrates the schematics of a CCTS, where l 1 and l 2 need to be regulated. Article [4] describes the transfer function of CCTS as Thus, the proposed decentralized PID controller from Equation ( 29) is [ 18.9 + 2.9 s + 3.5s 0 0 1 2 .7…”

“…The tank heights l 1 and l 2 need to be regulated as shown in Figure 9. The process transfer function of CSTS as presented in [4] is (Figure 13)…”

“…trollers has been proposed in [3,4]. While centralized controllers can attain the desired operating criteria, they compromise stability and involve complex tuning procedures.…”

Advanced tree‐seed optimization based fractional‐order PID controller design for simplified decoupled industrial tank systems

“…A robust decentralized controller design for controlling the level of a CTS is discussed in Refs. 12,13. The controllers are realized with frequency domain specifications and by employing non‐linear constraint optimization.…”