Application of FRF estimator based on errors-in-variables model in multi-input multi-output vibration control system

The FRF estimator based on the errors-in-variables (EV) model of multi-input multi-output (MIMO) system is presented to reduce the bias error of FRF H1 estimator. The FRF H1 estimator is influenced by the noises in the inputs of the system and generates an under-estimation of the true FRF. The FRF estimator based on the EV model takes into account the errors in both the inputs and outputs of the system and would lead to more accurate FRF estimation. The FRF estimator based on the EV model is applied to the waveform replication on the 6-DOF (degree-of-freedom) hydraulic vibration table. The result shows that it is favorable to improve the control precision of the MIMO vibration control system.