In this chapter, an improved relay auto-tuning method, considering the higher-order harmonics, is proposed for different classes of the second-order unstable systems. © 2018, Springer Nature Singapore Pte Ltd.

Manickam Chidambaram

AUTO-TUNING METHODS

Autotuning

Different class

Higher order harmonics

Second orders

Unstable system

Control engineering

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Auto-Tuning of Unstable SOPTD Systems

Advances in Industrial Control

A method is presented to identify the steady-state gain matrix of a multivariable (SSGM) unstable system under closed-loop control. Effects of disturbances and measurement noise on the identification of SSGM were also studied. Davison's method (Davison, 1976) was modified to design single-stage multivariable PI controllers using only the steady-state gain matrix of the system. Since the overshoots in the responses are larger, a two-stage P-PI control system is proposed. Based on the SSGM, a simple proportional controller matrix was designed by the modified Davison's method (1976) to stabilize the system. Based on the gain matrix of the stabilized system, diagonal PI controllers were designed. The performance of the two-stage control system was evaluated and compared with that of single-stage multivariable controllers. Simulation results on two examples show the effectiveness of the proposed methods for both servo and regulatory problems. © 2015, Taylor & Francis Group, LLC.

Chemical Engineering Communications

Steady-State Gain Identification and Control of Multivariable Unstable Systems

The asymmetrical relay feedback method is modified to get improved parameters estimates of a first order plus time delay transfer function model. The method uses a single relay test. Analytical solution is provided for the model parameters. The method overcomes the problem of getting a negative time constant by the conventional symmetrical relay testing for modeling higher order system. Simulation results are given for stable and unstable transfer function models. The proposed method gives model parameters close to the actual values and gives closed loop ISE values similar to that of the actual system. The method is also compared with that of Huang et al. (AIChE J., 42 (1996) 2687) and Shen et al. (AIChE J., 42 (1996) 1174). © 2002 Elsevier Science Ireland Ltd. All rights reserved.

Computers and Chemical Engineering

Modified relay feedback method for improved system identification

PID Control in the Third Millennium

AIChE Journal

An experimental investigation of stability and multiplicity of steady states in a biological reactor

Auto-tuning of unstable SOPTD systems

Journal	Data powered by TypesetAdvances in Industrial Control
Publisher	Data powered by TypesetSpringer International Publishing
ISSN	14309491
Open Access	No