Identification of two-input two-output process using state-space analysis

An analytical expression for the exact identification of two-input two-output (TITO) process using hysteresis relay is presented in this study. The identified transfer matrix consists of four independent first-order plus delay time (FOPDT) models and the time constants, delays and the gains of the FOPDT models are obtained from the limit cycle measurements. In this study, analytical expressions are derived using state-space analysis to identify the exact transfer matrix of the TITO process (TITO system). Problem of chattering and measurement noise is attenuated using relay with hysteresis. The simulation examples and real-time experiment show the effectiveness of the proposed method.