A Fourier series based iterative learning control for nonlinear uncertain systems

A Fourier series based learning controller for the tracking control of nonlinear uncertain systems is proposed. The Fourier series based learning controller consists of a PD part and a learning part. The learning part generates a feedforward term based on the Fourier series approximation of the PD output. By introducing a system input-output (I/O) mapping matrix, the coupling effects of the PD output harmonics in the Fourier space are considered in our algorithm instead of treating them individually. Trajectory tracking experiments conducted on a belt driven positioning table indicated that the proposed method was more effective than the same type of controller without the I/O matrix