Abstract: An improved Dtype learning law with timevarying exponential gain and initial state learning was proposed and the certification of convergence for this learning law was given for the planar 2DOF manipulator which is an nonlinear system. Simulation results showed that the iterative learning control was very effective for the planar 2DOF manipulator system which owned property of repetitiveness. Dtype learning law with timevarying exponential gain and initial state learning was obtained which could eliminate the impact of the initial state migration on tracking performance and improve the convergence rates of the algorithm. What’s more， the robustness of iterative learning control was also improved.

Key words: 2DOF manipulator, iterative learning control(ILC), Dtype learning law, initial state learning, timevarying exponential gain