Robust PD-Type Iterative Learning Fault-Tolerant Control for Discrete Systems with Polytopic Uncertainties and Actuator Faults

For a class of discrete systems with polytopic uncertainties and actuator faults, a robust PD-type iterative learning fault-tolerant control scheme is investigated in this article. By providing a two-dimensional analysis of the learning process, the fault system of a repetitive nature is equivalently converted into an uncertain linear repetitive process. Additionally, employing repetitive process stability theory, new sufficient conditions with less conservatism for the robust stability of the designed fault-tolerant controller are derived in terms of linear matrix inequality constraints. The controller gain matrices are exactly given as well. Finally, simulation results of an industrial SCARA robot demonstrate the efficiency and feasibility of the proposed strategy in comparison to the developed robust P-type iterative learning fault-tolerant control strategy.