Accuracy of relay identification depending on relay parameters

Abstract

Combination of relay feedback experiment and control synthesis is usually a part of autotuning principles. This contribution deals with the relay based identification of continuous time plants because the knowledge of the controlled system parameters is important for the quality of control. The feedback relay schemes can use different types of relays. This paper is focused on biased relay with hysteresis. The controlled system is identified as a first order transfer function because most of industrial plants can be sufficiently approximated by a first order linear stable system with time delay term. The main aim is to analyze the precision of controlled system parameters identification when the feedback relay parameters will vary. Matlab program environment is used for all simulations conducted in this paper. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.