Discussion on "Torque Ripple Minimization of PMSM Based on Robust ILC via Adaptive Sliding Mode Control"

This discussion note extends the robust iterative learning control (RILC) design for a class of nonlinear systems with unknown dynamic and control gain uncertainty by discussing and amending the preliminary design. To minimize the tracking error of the steady state from the initial time instant, adaptive robust controller design is first presented based on the integral sliding mode (ISM) surface. Then, an appropriate update law in the iteration domain for the designed controller is organized by a composite energy function (CEF). The convergence of the ISM is obtained. Finally, the RILC design based on the ISM is applied to a simulation of a one-link robotic manipulator. The simulation results validate the performance of the control design.