Convocatoria del Programa Redes del Instituto de Ciencias de la Educacion (ICE). Convocatoria de ayudas a la creacion de Grupos de Innovacion Tecnologico-Educativa (GITE).
Actualmente, la utilización de herramientas de simulación como ROS/Gazebo es una práctica habitual para la simulación y desarrollo de algoritmos de control para sistemas robóticos terrestres típicos. Sin embargo, en la actualidad aún no está comúnmente aceptado en la comunidad espacial. Numerosos estudios en el campo de la robótica espacial utilizan herramientas construidas ad-hoc, pero que no están estandarizadas, que no son de código abierto y que, además, no han sido verificadas, lo que complica el desarrollo y la simulación de sistemas robóticos versátiles y algoritmos para el control de sistemas robóticos espaciales. Este artículo propone una solución de código abierto para la simulación de robots espaciales en órbita denominada OnOrbitROS. Este trabajo presenta una descripción de la arquitectura, los diferentes módulos software y las posibilidades de simulación de OnOrbitROS. Se describen las características clave de la herramienta desarrollada, con especial atención a la personalización de las simulaciones y a las posibilidades de ampliación de la herramienta. Con el fin de mostrar estas capacidades, se describen los resultados obtenidos al aplicar OnOrbitROS para la simulación del robot ETS-VII.
En los ultimos anos las plataformas de hardware libre han adquirido gran relevancia en el desarrollo de prototipos y en la educacion en tecnologia. Una plataforma de hardware libre es basicamente un diseno de sistema un electronico microprocesador que sus autores difunden libremente y puede ser utilizado sin tener que pagar licencias. Ente la multitud de plataformas disponibles, destaca Arduino. Se caracteriza por su bajo precio, y que el software necesario para hacer funcionar la plataforma es libre y gratuito. Todo ello hace que estos dispositivos sean facilmente accesibles por estudiantes. Este trabajo describe la aplicacion de hardware libre a experimentos de laboratorio en asignaturas de ingenieria de la UA, especialmente del master en Automatica y Robotica, en las que se controlan sistemas industriales o roboticos. Esto contrasta con los experimentos clasicos en los que se emplean sistemas caros y dificilmente accesibles por el alumno. Ademas, los experimentos deben ser atractivos y de aplicaciones reales, para atraer el interes del alumno, con el objetivo principal de que aprenda mas y mejor en el laboratorio.
Visual servoing is a well-known approach to guide robots using visual information [...]
The control problem for the multivariable and nonlinear dynamics of robotic manipulators and autonomous vehicles is solved with the use of a flatness-based control approach which is implemented in successive loops. The state-space model of these robotic systems is separated into two subsystems, which are connected between them in cascading loops. Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearised flat systems. The state variables of the second subsystem become virtual control inputs for the first subsystem. In turn, exogenous control inputs are applied to the first subsystem. The whole control method is implemented in two successive loops and its global stability properties are also proven through Lyapunov stability analysis. The validity of the control method is confirmed in two case studies: (a) control of a 3-DOF industrial rigid-link robotic manipulator and (b) control of a 3-DOF autonomous underwater vessel. The novel control method can simplify significantly the solution of the nonlinear control problem for robotic manipulators and vehicles. Unlike global linearisation-based control schemes, the proposed flatness-based method in successive loops does not need any changes in state variables of complicated state-space model transformations.
Abstract This paper proposes a direct visual servoing system for spacecraft guidance in formation flying scenarios. The proposed image-based visual servoing system uses image information for planning and executing formation acquisition, reconfiguration, and maintenance maneuvers. The system assumes that LEDs are located at specific points on the satellites, enabling the visual servoing controller to rely on continuous tracking of these features in the camera’s image plane. Analytical developments demonstrate that the proposed optimal visual control system is stable and optimal, and it acts on both the orbital and attitude dynamics of the spacecraft, considering circular and elliptical reference orbits. The distributed image-based controller defines a cost function that minimizes control efforts, and the paper proses an optimal framework for developing controllers that address the issue. A ROS-based simulation tool was used to test the proposed visual servoing controller in a realistic small-sat formation flying scenario. Results indicate that the proposed distributed control strategy is viable and robust against environmental perturbations and disturbances in sensing and actuation.
The utilization of zooming cameras during a non-cooperative rendezvous in space is investigated in this paper. An image-based controller, utilizing visual servoing techniques usually applied to ground-based robotic systems, is designed for the particular problem of far-to-close approach of a spacecraft to a non-cooperative object. The controller directly utilizes the visual features from image frames of the noncooperative target for computing both attitude and orbital maneuvers concurrently. The additional feature derived from the utilization of the zooming camera gives a greater versatility to the maneuvers if compared with the classic fixed optics approaches. The stability of the proposed controller is proven analytically in the invariant space, and its viability is explored through the application to a realistic space debris removal scenario.
Las aplicaciones de este tipo de sistemas son muy amplias, asi, encontramos trabajos en la actualidad en los que se describe algunas de ellas como en [5] que usa la alta resolucion de un dispositivo optico, por ejemplo, un microscopio, para realizar el microposicionamiento de las partes implicadas realizando una servo-visualizacion. Corke, Roberts y Winstanley [2], describen una aplicacion para la industria minera. De nuevo, en [10] encontramos una aplicacion de visual servoing aplicada a la robotica, en este caso se trata de aplicar a tareas de navegacion de un robot el conocimiento proporcionado de la realimentacion visual.
Abstract In this article, a nonlinear optimal control approach is proposed for the dynamic model of 3-DOF four-cable driven parallel robots (CDPR). To solve the associated nonlinear optimal control problem, the dynamic model of the 3-DOF cable-driven parallel robot undergoes approximate linearization around a temporary operating point that is recomputed at each time-step of the control method. The linearization relies on Taylor series expansion and on the associated Jacobian matrices. For the linearized state-space model of the 3-DOF cable-driven parallel robot a stabilizing optimal (H-infinity) feedback controller is designed. To compute the controller’s feedback gains an algebraic Riccati equation is repetitively solved at each iteration of the control algorithm. The stability properties of the control method are proven through Lyapunov analysis. The proposed nonlinear optimal control approach achieves fast and accurate tracking of reference setpoints under moderate variations of the control inputs and a minimum dispersion of energy.
