A novel closed-form solution for the inverse kinematics of redundant manipulators through workspace analysis

© 2017 Elsevier Ltd This work addresses the inverse kinematic problem for redundant serial manipulators. Its importance relies on its effect in the programming and control of redundant robots. Besides, no general closed-form techniques have been developed so far. In this paper, redundant manipulators are reduced to non-redundant ones by selecting a set of joints, denoted redundant joints, and parametrizing its joint variables. This selection is made through a workspace analysis which also provides an upper bound for the number of different closed-form solutions for a given pose. Once these joints have been identified several closed-form methods developed for non-redundant manipulators can be applied for obtaining the analytical solutions. Finally, particular instances for the parametrized joints variables are determined depending on the task to be executed. Different criteria and optimization functions can be defined for that purpose.Peer ReviewedPostprint (author's final draft

Bilateral haptic guided Robot teleoperation via packet switched networks using wave variables with impedance adaptation

This paper presents the use of haptic devices in teleoperation systems with motion restrictions during robot teleoperation in order to provide the operator with increased awareness and better feeling of immersion, hence, improving his ability to perform complex tasks. The use of wave variables in the proposed system renders passive the communication channel, and moreover the new packet switched protocols like Internet Protocol version 6 (IPv6) with high Quality of Service (QoS), provides differentiated services for control signals.Peer Reviewe

Análisis cinemático de robots manipuladores redundantes: Aplicación a los robots Kuka LWR 4+ y ABB Yumi

En este trabajo se presenta un análisis cinemático aplicado a dos manipuladores serie redundantes: el Kuka LWR 4+ y el ABB Yumi. En particular, se deriva la cinemática directa para ambos manipuladores y se resuelve el problema de la cinemática inversa. Para el Kuka LWR 4+ dicha solución se obtiene en forma analítica, mientras que para el ABB Yumi se sigue un enfoque analítico y numérico. Además, se calculan simbólicamente tanto las singularidades del Kuka LWR 4+ como las direcciones singulares asociadas a éstas. Este estudio contribuye al conocimiento cinemático de dos manipuladores redundantes de gran actualidad e interés para la comunidad robótica, y proporciona información útil para el diseño de diferentes algoritmos y leyes de control.Postprint (author's final draft

Exploiting the robot kinematic redundancy for emotion conveyance to humans as a lower priority task

Current approaches do not allow robots to execute a task and simultaneously convey emotions to users using their body motions. This paper explores the capabilities of the Jacobian null space of a humanoid robot to convey emotions. A task priority formulation has been implemented in a Pepper robot which allows the specification of a primary task (waving gesture, transportation of an object, etc.) and exploits the kinematic redundancy of the robot to convey emotions to humans as a lower priority task. The emotions, defined by Mehrabian as points in the pleasure–arousal–dominance space, generate intermediate motion features (jerkiness, activity and gaze) that carry the emotional information. A map from this features to the joints of the robot is presented. A user study has been conducted in which emotional motions have been shown to 30 participants. The results show that happiness and sadness are very well conveyed to the user, calm is moderately well conveyed, and fear is not well conveyed. An analysis on the dependencies between the motion features and the emotions perceived by the participants shows that activity correlates positively with arousal, jerkiness is not perceived by the user, and gaze conveys dominance when activity is low. The results indicate a strong influence of the most energetic motions of the emotional task and point out new directions for further research. Overall, the results show that the null space approach can be regarded as a promising mean to convey emotions as a lower priority task.Postprint (author's final draft

Haptic guidance with force feedback to assist teleoperation systems via high speed networks

The employment of haptic devices in teleoperation systems and the use of motion restrictions during robot teleoperation provide the operator with increased awareness and can considerably improve the feeling of immersion and moreover his ability to perform complex tasks. In the last decade Internet has become one of the major sources of information. It already connects millions of computers and more than a billion people. Its spectacular growth have lead to the creation of new high speed networks with new capabilities. In the work described in this paper those networks that use recent-creation packet switched protocols like Internet Protocol version 6 (IPv6) with high Quality of Service (QoS) will serve as the communication channel for the teleoperation system.Peer Reviewe

Teleoperating a mobile manipulator and a free-flying camera from a single haptic device

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper presents a novel teleoperation system that allows the simultaneous and continuous command of a ground mobile manipulator and a free flying camera, implemented using an UAV, from which the operator can monitor the task execution in real-time. The proposed decoupled position and orientation workspace mapping allows the teleoperation from a single haptic device with bounded workspace of a complex robot with unbounded workspace. When the operator is reaching the position and orientation boundaries of the haptic workspace, linear and angular velocity components are respectively added to the inputs of the mobile manipulator and the flying camera. A user study on a virtual environment has been conducted to evaluate the performance and the workload on the user before and after proper training. Analysis on the data shows that the system complexity is not an obstacle for an efficient performance. This is a first step towards the implementation of a teleoperation system with a real mobile manipulator and a low-cost quadrotor as the free-flying camera.Accepted versio

Passive bilateral teleoperation framework for assisted robotic tasks

This paper addresses the problem of stable bilateral teleoperation, through a time-delayed communication channel, for a n-DOF system without position drift. The classical wave variables-based scheme encodes velocity and force whilst the proposed scheme encodes position and integral of force. The resulting passive communication scheme is used in an extended teleoperation framework, in which the human operator can define geometrical motion restrictions in order to increase his awareness and his feeling of immersion, hence improving his ability to perform complex tasks. The framework also provides the operator with video feedback and 3D rendering of the remote scene.Peer Reviewe

Modelo cinemático de la interfase háptica PHANTnOM Premium 1.5/6DOF

En el presente reporte se deriva de la cinemática directa e inversa, así como el Jacobiano de la interfase háptica PHANTOM Premium 1.5/6DO

Description of a robotics-oriented relational positioning methodology

This paper presents a relational positioning methodology for flexibly and intuitively specifying offline programmed robot tasks, as well as for assisting the execution of teleoperated tasks demanding precise movements. In relational positioning, the movements of an object can be restricted totally or partially by specifying its allowed positions in terms of a set of geometric constraints. These allowed positions are found by means of a 3D sequential geometric constraint solver called PMF – Positioning Mobile with respect to Fixed. PMF exploits the fact that in a set of geometric constraints, the rotational component can often be separated from the translational one and solved independently

Planificación de Movimientos y Control de Fuerza en Entornos Multi-Robot

[ES] En este artículo se presentan las características y posibilidades más destacadas de los sistemas multi-robot en los que diferentes robots actúan de manera coordinada en un espacio de trabajo compartido. A tal efecto, se pasa revista a los principales enfoques existentes y a los algoritmos utilizados para la planificación y control de estos sistemas. El artículo se completa con una breve exposición de algunos trabajos realizados en los últimos tiempos en el Institut d’Organització i Control de Sistemes Industrials (IOC) dentro de este ámbito.Este trabajo ha sido parcialmente financiado por los proyectos CICYT DPI2002-03540 y CICYT DPI2001-2202.Costa Castelló, R.; Basañez Villaluenga, L. (2010). Planificación de Movimientos y Control de Fuerza en Entornos Multi-Robot. Revista Iberoamericana de Automática e Informática industrial. 1(3):29-42. http://hdl.handle.net/10251/146616OJS29421