Enhanced relay feedback method

Abstract

An enhanced relay feedback identification method is proposed to identify three frequency data sets from one relay feedback test. The identified data sets are exact for time-invariant linear systems. The method also gives the exact frequency data set corresponding to the multiple of the relay frequency in the presence of a static disturbance. This means that, even though the initial state is not steady state or wrong reference values for relay on-off are specified, it provides an exact data set.