Model following adaptive control for a robot with flexible joints

In this paper we introduce a method based on model following adaptive control for non-linear flexible joint robots with time-varying parameters. A dynamic model of a manipulator with flexible joint is derived to establish the control law. Under the assumption of weak joint elasticity, a singular perturbation argument is used to show that recent adaptive control results for flexible-joint robots. In this strategy a plant should follow a suitable model reference. Despite of imprecise parameters of the manipulator and presence of joints flexibility, the tracking error will converge to zero and the robot stability is guaranteed. A 5 bar linkage robot with three revolute flexible joints is considered as a case study. Simulation results show the effectiveness of the proposed method.