Velocity field control of a class of electrically-driven manipulators |
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Authors: | Javier Moreno-Valenzuela Ricardo Campa Víctor Santibáñez |
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Affiliation: | 1. Department of Systems and Control , Instituto Politécnico Nacional–CITEDI , Ave. del Parque 1310, Mesa de Otay, Tijuana , 22510, Mexico;2. Instituto Tecnológico de La Laguna , Blvd. Revolución y Cuauhtémoc, Torreón , 27000, Mexico |
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Abstract: | This article addresses the control of robotic manipulators under the assumption that the desired motion in the operational space is encoded through a velocity field. In other words, a vectorial function assigns a velocity vector to each point in the robot workspace. Thus, the control objective is to design a control input such that the actual operational space velocity of the robot end-effector asymptotically tracks the desired velocity from the velocity field. This control formulation is known in the literature as velocity field control. A new velocity field controller together with a rigorous stability analysis is introduced in this article. The controller is developed for a class of electrically-driven manipulators. In this class of manipulators, the passivity property from the servo-amplifier voltage input to the joint velocity is not satisfied. However, global exponential stability of the state space origin of the closed-loop system is proven. Furthermore, the closed-loop system is proven to be and output strictly passive map from an auxiliary input to a filtered error signal. To confirm the theoretical conclusions, a detailed experimental study in a two degrees-of-freedom direct-drive manipulator is provided. Particularly, experiments consist of comparing the performance of a simple PI controller and a high-gain PI controller with respect to the new control scheme. |
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Keywords: | velocity field control robot manipulator Lyapunov function stability real-time experiments |
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