http://hdl.handle.net/2117/7009 2013-05-20T14:01:58Z http://hdl.handle.net/2117/18505 Title: Valoración del daño corporal en personas afectadas de secuelas neurológicas Authors: Peña Pitarch, Esteve; Ticó Falguera, Neus Abstract: Objetivo: Mostrar un nuevo sistema para simular la recuperación inicial de las funciones de la extremidad superior los primeros días después del ictus y simular la recuperación funcional de los pacientes bajo los programas de rehabilitación. Pacientes y metodología: Seleccionamos 29 pacientes en los primeros cuatro días después de padecer un ictus, valorados a los tres y siete días y uno, tres y seis meses, recogiendo tipo de ictus, clasificación (escala de Oxford), déficit neurológico (escala de NIHSS), medidas de discapacidad, valoración de la función motora de la extremidad superior (escala de Fugl-Meyer), tono muscular y balance muscular de la extremidad superior. Resultados: Los pacientes que presentaron un tono muscular disminuido tuvieron más dificultad en mejorar el control motor de las articulaciones de la extremidad superior. Los pacientes TACI presentaron mayor déficit neurológico, mientras que los tipos de ictus POCI y LACI tenían una función motora mejor con mayor independencia para el desarrollo de sus actividades de la vida diaria. Conclusión: La simulación virtual del brazo y la mano en pacientes afectados por un ictus proporciona a los médicos y fisioterapeutas una nueva herramienta que permite simular la evolución de los déficits en algunos pacientes. 2013-03-22T16:16:33Z http://hdl.handle.net/2117/18133 Title: Coordination of multi-agent systems via energy–shaping: networking improves robustness Authors: Nuño Ortega, Emmanuel; Ortega, Romeo; Jayawardhana, Bayu; Basañez Villaluenga, Luis Abstract: In this paper the problem of robust coordination of multi–agent systems via energy–shaping is studied. The agents are nonidentical, Euler–Lagrange systems with uncertain parameters. The control objective is to drive all agents states to the same constant equilibrium— which is achieved shaping their potential energy function. It is assumed that, if the parameters are known, this task can be accomplished with a decentralized strategy. In the face of parameter uncertainty, the assigned equilibrium is shifted away from its desired value. It is shown that adding information exchange between the agents to this decentralized control policy improves the performance. More precisely, it is proven that if the communication graph is undirected and connected, the equilibrium of the networked controller is always closer (in a suitable metric) to the desired one. If the the potential energy functions are quadratic, the result holds for all interconnection gains, else, it is true for sufficiently large gains. The decentralized controller is the well–known energy–shaping proportional plus derivative controller, extensively used in applications. An additional advantage of networking is that the control objective is achieved injecting lower gains into the loop. 2013-03-07T13:26:31Z http://hdl.handle.net/2117/18122 Title: A proportional plus damping injection controller for teleoperators with joint fexibility and time–delays Authors: Nuño Ortega, Emmanuel; Sarras, Ioannis; Basañez Villaluenga, Luis; Kinnaert, Michel Abstract: The problem of controlling a rigid bilateral teleoperator with time-delays has been effectively addressed since the late 80’s. However, the control of flexible joint manipulators in a bilateral teleoperation scenario is still an open problem. In the present paper we report two versions of a proportional plus damping injection controller that are capable of globally stabilizing a nonlinear bilateral teleoperator with joint flexibility and variable time-delays. The first version controls a teleoperator composed by a rigid local manipulator and a flexible joint remote manipulator and the second version deals with local and remote manipulators with joint flexibility. For both schemes, it is proved that the joint and motor velocities and the local and remote position error are bounded. Moreover, if the human operator and remote environment forces are zero then velocities asymptotically converge to zero and position tracking is established. Simulations are presented to show the performance of the proposed controllers. 2013-03-07T12:05:43Z http://hdl.handle.net/2117/18117 Title: An adaptive controller for bilateral teleoperators: transatlantic experiments using the internet Authors: Nuño Ortega, Emmanuel; Basañez Villaluenga, Luis; de Alba Padilla, Carlos; López Franco, Carlos Abstract: A bilateral teleoperator is composed of a local and a remote manipulators interconnected through a communication channel. A human operator interacts with the local manipulator to remotely execute a given task via the remote manipulator and the interaction of the remote manipulator with the remote environment is reflected back to the human operator. Thus, the control objective is to establish local and remote position synchronization. This paper employs adaptive control techniques, that can achieve the desired control objective, to an experimental setup composed of two nonlinear manipulators. In these novel experimental results the local and remote manipulators are located in Guadalajara, Mexico, and in Barcelona, Spain, respectively. The manipulators are two Sensable's PHANToM Omni® devices and are interconnected through the Internet. It is shown, experimentally, that the adaptive controllers provide asymptotic stability of the local and remote position error even in the presence of variable timedelays. 2013-03-07T11:19:37Z http://hdl.handle.net/2117/18116 Title: Consensus in networks of nonidentical Euler-Lagrange systems with variable time-delays Authors: Nuño Ortega, Emmanuel; Sarras, Ioannis; Panteley, Elena; Basañez Villaluenga, Luis Abstract: The present work reports a sufficient condition for the consensus of a network of nonidentical Euler-Lagrange (EL) systems with variable time-delays in the communications. The EL-systems are controlled by simple Proportional plus damping (P+d) schemes and the interconnection network is modeled as an undirected weighted graph. Additionally, for the case without delays, the paper reports a new Strict Lyapunov Function (SLF)for the closed-loop system. Experimental evidence, using three 3-Degrees-of-Freedom manipulators interconnected through the Internet, support the theoretical results of this paper. 2013-03-07T10:40:21Z http://hdl.handle.net/2117/17851 Title: Búsqueda de caminos libres de colisiones para un sistema bimanual considerando la eliminación de obstáculos movibles Authors: Rodríguez Pacheco, Carlos; Montaño Sarria, Andrés Felipe; Suárez Feijóo, Raúl Abstract: Este art´ıculo aborda el problema de la planificación de movimientos de un sistema de dos manos para la sujeción un objeto con una mano utilizando la otra mano para quitar los posibles obstáculos que se encuentren en la trayectoria hacia la meta. Este enfoque se basa en Mapas de Carreteras Probabilístico (del inglés, Probabilistic Road Maps (PRM)), con la particularidad de que no se descartan las muestras en colisión con objetos movibles, sino que son clasificadas y etiquetadas de acuerdo con el obstáculo con que colisiona,y se permite la búsqueda de caminos considerando los obstáculos movibles que deben ser quitados del espacio de trabajo para obtener una ruta de acceso v´alida. El método ha sido implementado y se presentan diferentes pruebas utilizando un modelo virtual del sistema bimanual,teniendo en cuenta que uno de los robots es el que se encarga de sujetar el objeto deseado (meta) y el otro de quitar los obst´aculos encontrados. 2013-02-18T15:19:05Z http://hdl.handle.net/2117/17845 Title: Hybrid mapping for the assistance of teleoperated grasping tasks Authors: Colasanto, Luca; Suárez Feijóo, Raúl; Rosell Gratacòs, Jan Abstract: Teleoperating a robotic hand with the aid of a sensorized glove presents some particular problems. A certain problem is due to the kinematic differences between the human hand and the robotic hand, which do not allow a simple direct mapping of the sensor readings from the glove to the robotic hand. This problem is addressed with different types of mapping, but none of them is of general use. This paper proposes two new mappings within two existing mapping types, as well as a new hybrid mapping that combines the best features of these existing mapping types. This hybrid mapping allows intuitive free space movements (where the gesture is more important than the precise positions of the fingers) and grasp movements (where the precise positions of the fingers is more important than the gesture), despite kinematic differences between the human hand and the robotic hand. The approach has been implemented, and some illustrative examples are presented in this paper. 2013-02-18T14:58:29Z http://hdl.handle.net/2117/17837 Title: Determining force-closure grasps reachable by a given hand Authors: Gilart, Fidel; Suárez Feijóo, Raúl Abstract: The paper presents an approach to find contact points on an object surface that are reachable by a given hand and such that the resulting grasp satisfies the force-closure condition. This is a very common problem that still requires a practical solution. The proposed method is based on the computation of a set of independent contact regions on the object boundary such that a finger contact on each region produces a force-closure grasp, and then this set of regions is iteratively recomputed while looking for a set of contact points that are reachable by a given hand. The search is done guided by a cost function that indicates the proximity of the hand fingertips to a candidate set of grasping contact points. The approach has been implemented for the Schunk Anthropomorphic Hand and planar objects,and application examples are included to illustrate its performance. 2013-02-18T14:30:58Z http://hdl.handle.net/2117/17834 Title: Coordinación temporal de dos robots manipuladores Authors: Montaño Sarria, Andrés Felipe; Suárez Feijóo, Raúl Abstract: En este art´ıculo se presenta un m´etodo de coordinaci´on de movimientos en tiempo real que permite que dos robots industriales equipados con manos rob´oticas puedan ejecutar simult´aneamente tareas de manipulaci´on de objetos en una celda de trabajo compartida, evitando las posibles colisiones debidas a la planificaci´on desacoplada de los movimientos de cada robot. Para ilustrar el m´etodo propuesto se muestran experimentos en los que se asign´o a cada robot la tarea de retirar objetos de un mesa para llevarlos a una posici´on donde los puede recibir un operario. 2013-02-18T14:09:56Z http://hdl.handle.net/2117/17829 Title: Using path planning techniques to improve airway tree segmentation from CT images Authors: Cabras, Paolo; Rosell Gratacòs, Jan Abstract: Virtual Bronchoscopy (VB) permits the preplanning of operations concerning the airways and provides the necessary guidance to reach the pulmonary lesions. Fundamental for a good VB is the reconstruction of a 3D model of the airways from the CT images. Airway segmentation algorithms usually return the biggest detected volume connected to the trachea (the root tree), but many of them also reconstruct during the segmentation process, small parts not connected to the root tree. To overcome this problem this paper proposes a method, based on path planning techniques, that is able to connect the small isolated pieces of bronchi to the terminal points of the root airway tree, taking into account the growing direction of the branches and the gray values of the CT images. As a result, a more complete 3D model of the airways is obtained. 2013-02-18T13:09:52Z http://hdl.handle.net/2117/17794 Title: Instrumento quirúrgico de sutura para anastomosis automática del tubo digestivo Authors: Tornero García, José Antonio; Suárez Feijóo, Raúl; Cano Casas, Francesc; Montaño Sarria, Andrés Felipe; López Cano, Manuel Abstract: En la cirugía digestiva, una anastomosis del intestino consiste en la reconstrucción del tubo digestivo por unión de dos cabos tras la resección de una porción del mismo. Este procedimiento, de común aplicación en diversos tipos de intervención quirúrgica se realiza actualmente mediante la aplicación de grapas metálicas debido a la complejidad inherente de la realización de una sutura manual. La automatización del proceso de sutura mediante un dispositivo diseñado a tal efecto supondría una notable mejora en el procedimiento quirúrgico asociado y posteriormente en la calidad de vida del paciente, ya que las grapas metálicas empleadas actualmente presentan diversos inconvenientes. El diseño de este dispositivo presenta gran complejidad debido al rigor de los requisitos funcionales y a la complejidad del entorno de funcionamiento así como las características de los materiales que intervienen en el proceso.En el presente trabajo se describe el desarrollo de un prototipo de dispositivo para anastomosis automática mediante sutura, evaluando su funcionalidad a nivel de laboratorio, con objeto de probar su validez 2013-02-15T13:50:44Z http://hdl.handle.net/2117/17562 Title: Exoesqueleto para mano discapacitada con movimiento y sensibilidad, pero sin fuerza Authors: Peña Pitarch, Esteve; Ticó Falguera, Neus; López Martínez, Joan Antoni; Abenoza Guardiola, Montserrat; Romero Cullerés, Georgia Abstract: Personas con ciertas patologías tienen limitaciones en sus actividades de la vida diaria, tales como coger un vaso de agua o mover un objeto. Las ortesis ayudan a mejorar y/o restaurar la funcionalidad del sistema muscoesquelético en pacientes que tienen las limitaciones descritas. Este artículo presenta una de estas ortesis, un exoesqueleto para la mano discapacitada, con el fin de ayudar a mejorar sus actividades de la vida diaria. La novedad de este exoesqueleto patentado es que no necesita ningún tipo de energía externa para su activación. Un movimiento de la muñeca hace que se active, creando una cadena cinemática de movimientos que ayuda a agarrar el objeto. 2013-02-01T15:24:05Z http://hdl.handle.net/2117/17093 Title: Effect of human link length determination on posture reconstruction Authors: Gragg, J.; Yang, Jingzhou; Cloutier, A.; Peña Pitarch, Esteve 2012-12-11T09:03:49Z http://hdl.handle.net/2117/17092 Title: Nonlinear inverse optimization approach for determining the weights of objective function in standing reach tasks Authors: Zou, Q.; Zhang, Qinghong; Yang, Jingzhou; Cloutier, A.; Peña Pitarch, Esteve 2012-12-11T08:52:20Z http://hdl.handle.net/2117/16900 Title: On the synthesis of feasible and prehensile robotic grasps Authors: Rosales Gallegos, Carlos; Suárez Feijóo, Raúl; Gabiccini, Marco; Bicchi, Antonio Abstract: This work proposes a solution to the grasp synthesis problem, which consist of finding the best hand configuration to grasp a given object for a specific manipulation task while satisfying all the necessary constraints. This problem had been divided into sequential sub-problems, including contact region determination, hand inverse kinematics and force distribution, with the particular constraints of each step tackled independently. This may lead to unnecessary effort, such as when one of the problems has no solution given the output of the previous step as input. To overcome this issue, we present a kinestatic formulation of the grasp synthesis problem that introduces compliance both at the joints and the contacts. This provides a proper framework to synthesize a feasible and prehensile grasp by considering simultaneously the necessary grasping constraints, including contact reachability, object restraint, and force controllability. As a consequence, a solution of the proposed model results in a set of hand configurations that allows to execute the grasp using only a position controller. The approach is illustrated with experiments on a simple planar hand using two fingers and an anthropomorphic robotic hand using three fingers. 2012-11-13T07:43:53Z