Evaluation of three model reference adaptive control algorithms for robotic manipulators

This paper evaluates three model reference adaptive control (MRAC) schemes for completing a telerobotic task. The three proposed schemes are evaluated for accurate trajectory control of a general three-degree-of-freedom robotic manipulator, in the presence of large payload variations, and modeling inaccuracies. The three MRAC schemes evaluated are: (1) Computed-torque method, which uses the nonlinear dynamic model of the robot in the control formulation and Popov´s hyperstability criteria, (2) independent joint control method, which uses decoupled linear dynamic equations in the control formulation and based on Popov´s hyperstability criteria, and (3) independent joint control method based on sensitivity analysis. Computer simulations of a three-degree-of-freedom manipulator, with a large payload and fast maneuver are used to analyze the performance of the three schemes. The investigation shows the robustness of the computed-torque method when compared to the independent joint schemes.