A dead-zone based filter for systems with unknown parameters

In this paper, we focus on parameter estimation in systems with output noise. By adding a dead-zone to the linear adaptive estimator, it is shown that statistically the bounded output noise can be filtered out and that the true unknown parameters are estimated exactly. This time-domain noise filter, which applies to systems with unknown parameters, is denoted as filtered deadzone estimator and it is later extended to situation where the output noise is white noise. The difference between model disturbance and output noise is discussed and the extension to situation where both of them exist is proposed.