Design of Trajectories With Physical Constraints for Very Lightweight Single Link Flexible Arms

Abstract

This communication deals with feedforward control of light, flexible robotic arms. In particular we develop a new, objective method to design a family of trajectories that can be used as modified inputs which cancel the tip vibrations during the robot manoeuvres. This method takes into account the constraints encountered in real actuators (motors), such as a maximum motor torque, and those due to the mechanical limits of the link, such as the maximum deflection before reaching the elastic limit of the link. Parameters of the internal control of the actuators are also derived from the design process, gaining the fastest performance without saturating the motor. Lastly, we show some experimental results which clearly demonstrate the benefits of the new trajectories by comparing them to a linear one.