Relay feedback method under nonlinearity and static disturbance conditions

We proposed a new relay feedback method to manipulate output nonlinearities and static disturbances. It guarantees the symmetry of the relay output by setting the time length of the lower value of the relay to half that of the previous period. It also rejects the effects of static disturbances and output nonlinearity by changing the input reference value of the relay. We demonstrate with simple examples that the proposed method can be successfully applied to identify the Wiener-type nonlinear process with a static disturbance.