Passivity-based iterative learning control for 2DOF robot manipulators with antagonistic bi-articular muscles

This paper investigates iterative learning control based on passivity for two-degree-of-freedom (2DOF) robot manipulators with antagonistic bi-articular muscles. Firstly, a brief summary of dynamics of 2DOF robot manipulators with antagonistic bi-articular muscles is given. Next, an error dynamics of the bi-articular manipulator for iterative learning control that has an output strictly passivity property is constructed. Then, we propose an iterative learning control law for the bi-articular manipulator. The proposed torque input does not need the parameters for the accurate models. Convergence analysis of the closed-loop system is carried out based on passivity. Finally, simulation results are presented in order to confirm the effectiveness of the proposed control law.