A robust PD-type evolutionary learning control for nonlinear time-varying systems

A robust PD-type evolutionary learning control (PD-ELC) is proposed for the tracking problem of a class of nonlinear time-varying system. The proposed PD-ELC scheme is a combination of PD feedback control and feedforward control using the previous control input profiles in an iteration mode, so it is an on-line learning control. It can deal with the uncertainty of the initial state and initial output error during the iterations. The uniform boundary of the tracking error is established in the presence of the initialization error. The proposed control scheme has a simple and straightforward control structure that leads to its easy implementation. The effectiveness of the proposed PD-ELC is demonstrated through simulation studies.