Finding grasping configurations of a dexterous hand and an industrial robot

Given an industrial robot equipped with a dexterous hand and an object to be grasped with four grasping points determined on its faces, this paper deals with the problem of finding the joint configurations that allow to grasp that object. The proposed solution is based on an iterative optimization method that consecutively moves the joint that best contributes to reduce the distance of the fingertips to the desired locations. The method is particularized for a Stäubli RX90 robot and a dexterous hand MA-I with four fingers developed at the IOC’s Robotics Lab

Efficient and robust trajectory generation for robotic manipulators

© 2022 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 worksThis paper describes a procedure to generate valid robot trajectories for a given sequence of points defining a geometric path, which is a quite frequent output of many robot motion planners. The proposed approach takes into account physical constraints of the robot, as the maximum velocity and the maximum acceleration that each joint can reach, and has been implemented in C++ as a general tool that can be used with different robots.Peer ReviewedPostprint (author's final draft

A simple yet smart head module for mobile manipulators

© 2023 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 worksMobile manipulators working in semi-structured human environments need smart vision capabilities to perceive the world and interact with human operators. With this purpose in mind, this paper presents the development of a robotic head module composed of an OAK-D camera mounted on a pan-and-tilt WidowX XM430 structure. The OAK-D camera provides high-resolution images, including stereo vision and depth sensing, and advanced capabilities based on embedded artificial intelligence functions. These features combined with the high-range motion of the WidowX XM430, allow the head module to have advanced visual tracking capabilities. The implementation has been done using ROS (Robot Operating System), which allows the head module to be easily integrated to any mobile manipulator.Peer ReviewedPostprint (author's final draft

A framework for robotized teleoperated tasks

"Premio al mejor artículo presentado en ROBOT 2011" atorgat pel Grupo de Robótica, Visión y Control de la Universidad de Sevilla, la Universidad Pablo Olavide i el Centro Avanzado de Tecnologías Aeroespaciales.Teleoperation systems allow the extension of the human operator’s sensing and manipulative capability into a remote environment to perform tasks at a distance, but the time-delays in the communications affect the stability and transparency of such systems. This work presents a teleoperation framework in which some novel tools, such as nonlinear controllers, relational positioning techniques, haptic guiding and augmented reality, are used to increase the sensation of immersion of the human operator in the remote site. Experimental evidence supports the advantages of the proposed framework.Award-winningPostprint (published version

Resolución geométrica de la cinemática inversa de un robot sin muñeca esférica

Una de las aplicaciones más conocidas del álgebra geométrica en la ingenierìa consiste en proporcionar una formulación compacta de la cinemática de los robots manipuladores serie. Sin embargo, el uso de álgebra geométrica en el campo de la robótica está aún en sus inicios, y todavía hay varios problemas abiertos que pueden ser tratados con esta elegante y compacta formulación. En esta línea, el presente artículo introduce una estrategia basada en el álgebra geométrica conforme para resolver el problema de la cinemática inversa para un robot manipulador de 6 grados de libertad (GdL) sin muñeca esférica, para el cual es conocido que el problema de la cinemática inversa no tiene, en general, solución analítica. Para ello, la estrategia propuesta en este artículo se basará en la explotación de las propiedades algebraicas y geométricas del álgebra geométrica conforme como, por ejemplo, que toda isometría se puede representar de manera compacta como un rotor, y que los objetos geométricos no son más que multivectores.Peer ReviewedPostprint (author's final draft

Efficient Industrial Solution for Robotic Task Sequencing Problem With Mutual Collision Avoidance & Cycle Time Optimization

© 2022 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 worksIn the automotive industry, several robots are required to simultaneously carry out welding sequences on the same vehicle. Coordinating and assigning welding points between robots is a manual and difficult phase that needs to be optimized using automatic tools. The cycle time of the cell strongly depends on different robotic factors such as the task allocation among the robots, the configuration solutions and obstacle avoidance. Moreover, a key aspect, often neglected in the state of the art, is to define a strategy to solve the robotic task sequencing with an effective robot-robot collision avoidance integration. In this paper, we present an efficient iterative algorithm that generates a high-quality solution for Multi-Robotic Task Sequencing Problem. This latter manages not only the mentioned robotic factors but also aspects related to accessibility constraints and mutual collision avoidance. In addition, a home-developed planner ( RoboTSPlanner ) handling 6 axis has been validated in a real case scenario. In order to ensure the completeness of the proposed methodology, we perform an optimization in the task, configuration and coordination space in a synergistic way. Comparing to the existing approaches, both simulation and real experiments reveal positive results in terms of cycle time and show the ability of this method to be interfaced with both industrial simulation software and ROS-I tools.Peer ReviewedPostprint (published version

Geometric solution for the inverse kinematics of robots without spherical wrist

[Resumen] Una de las aplicaciones más conocidas del álgebra geométrica en la ingenierìa consiste en proporcionar una formulación compacta de la cinemática de los robots manipuladores serie. Sin embargo, el uso de álgebra geométrica en el campo de la robótica está aún en sus inicios, y todavía hay varios problemas abiertos que pueden ser tratados con esta elegante y compacta formulación. En esta línea, el presente artículo introduce una estrategia basada en el álgebra geométrica conforme para resolver el problema de la cinemática inversa para un robot manipulador de 6 grados de libertad (GdL) sin muñeca esférica, para el cual es conocido que el problema de la cinemática inversa no tiene, en general, solución analítica. Para ello, la estrategia propuesta en este artículo se basará en la explotación de las propiedades algebraicas y geométricas del álgebra geométrica conforme como, por ejemplo, que toda isometría se puede representar de manera compacta como un rotor, y que los objetos geométricos no son más que multivectores.[Abstract] One of the most known applications of geometric algebra in engineering consists of providing a compact formulation of the kinematics of serial robotic manipulators. However, the use of geometric algebra in the field of robotics is still in its early stages, and there are still several open problems that can be addressed with this elegant and compact formulation. In this context, this work introduces a strategy based on conformal geometric algebra to solve the inverse kinematics problem for a 6 degree-of-freedom (DOF) robotic manipulator without a spherical wrist, for which it is known that the inverse kinematics problem generally does not have an analytical solution. To achieve this, the strategy proposed in this work will rely on exploiting the algebraic and geometric properties of conformal geometric algebra such as, for instance, the fact that every isometry can be represented compactly as a rotor, and that geometric objects are nothing more than multivectors.Ministerio Ciencia e Innovación; PID2020-114819GB-I00Ministerio de Universidades; 2022UPC-MZC-9400

Is switching to solar energy a feasible investment? A techno-economic analysis of domestic consumers in Spain

Grid-connected photovoltaic (PV) facilities are more attractive than ever due to the electricity price surges and the reduction of solar energy generation costs. This paper develops a solving procedure including a simulation model to analyze the techno-economic performance of PV-battery facilities, taking into account the latest Spanish regulatory framework. The procedure finds the best facilities for multiple objectives, maximum profitability and maximum self-sufficiency, in different locations, load profiles and economic scenarios. The results indicate that PV modules are profitable without subsidies, with installations between 1 and 6 kWp. Meanwhile, batteries are only convenient when seeking maximum independence from the grid, with capacities up to 9 kWh. The findings suggest that the economic feasibility of facilities is influenced by the location and compensation rate surplus electricity, while the facility is mainly determined by the load profile. A sensitivity analysis shows that a variation in grid tariffs and technology prices has a limited impact on the facility's size but modifies the system's profitability. Finally, an analysis of the latest unprecedented grid price surges indicates that self-consumption facilities help become a more resilient society against unexpected events. Therefore, policymakers should keep promoting the adoption of these technologies and keep the current advantageous regulations.Peer ReviewedPostprint (published version

Finding grasping configurations of a dexterous hand and an industrial robot

Given an industrial robot equipped with a dexterous hand and an object to be grasped with four grasping points determined on its faces, this paper deals with the problem of finding the joint configurations that allow to grasp that object. The proposed solution is based on an iterative optimization method that consecutively moves the joint that best contributes to reduce the distance of the fingertips to the desired locations. The method is particularized for a Stäubli RX90 robot and a dexterous hand MA-I with four fingers developed at the IOC’s Robotics Lab

Nonlinear control and geometric constraint enforcement for teleoperated task execution

This work presents a multimodal teleoperation framework that makes use of novel tools and techniques, such as: nonlinear teleoperators control, for ensuring position tracking in the presence of variable time-delays; relational positioning, for increasing operator performance on precise movement execution by visually and haptically displaying geometric constraints; and augmented reality, for visually combining real and virtual information in a compelling way. Experimental evidence is presented that validates the aptitude of the different components of the proposed framework