Saturation relay vs. relay transient identification tests for a TDS model

Abstract

The paper brings a comparison of, two novel combinations of a relay identification test with a Time Delay System (TDS) model. Namely, the on/off plus saturation relay test and relay transient experiment are introduced. In the former case with more then two unknown model parameters, it is necessary to apply some technique for frequency response multiple-points identification; here, the Autotune Variation Plus (ATV+) procedure introducing an artificial delay is utilized. Limit cycles data are evaluated via an unordinary time-domain approach and using the Discrete Time Fourier Transform (DTFT), respectively. Both methodologies are verified and compared on a model of the circuit heating laboratory system with internal delays.