Three-degrees-of-freedom flexible robot position control robust to load changes

This paper proposes a new control method for a three-degree-of-freedom flexible robot. In the model, the mass is assumed to be concentrated at the end of the robotic arm. The main feature of the method is that it consists of two nested control loops: the inner one controls the angular positions of the motors and the external one the tip's position and cancels the vibration. The outer control loop, as will be shown, is robust to tip mass variations. Simulations are carried out, supposing different masses with succesfull results in trajectory tracking.