Abstract: An improved iterative learning control algorithm for tracking slow varying and repetitive trajectory is proposed. The mathematical analyses for stability and convergence of the algorithm are also given. In addition, the experiment applying the presented algorithm on a complex trace tracking is processed. The theoretical analyses and experiment results show that the restricts on repetitive requirement for trajectory and initial condition as well as system dynamics are capable of being loosened at a certain accuracy requirement, and the system stability is still acquisitive. High accuracy is also achievable in machining.

Key words: Iterative learning control, Non-circular machining, Repetitiveness