An on-line PID control scheme for unknown nonlinear dynamic systems using evolution strategy

The paper presents an on-line PID control scheme with varying gains for unknown nonlinear dynamic systems. For the on-line control, it is necessary to have an on-line identifier of the system, so that an identifier is constructed in the form of an autoregressive moving average (ARMA) model. In order to tune the parameters of the identifier and the gains of the PID controller efficiently, we propose a modified evolution strategy. Experimental studies show that the proposed on-line control scheme has robust control performance under unknown disturbance and noise