694 research outputs found

    An intelligent, free-flying robot

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    The ground based demonstration of the extensive extravehicular activity (EVA) Retriever, a voice-supervised, intelligent, free flying robot, is designed to evaluate the capability to retrieve objects (astronauts, equipment, and tools) which have accidentally separated from the Space Station. The major objective of the EVA Retriever Project is to design, develop, and evaluate an integrated robotic hardware and on-board software system which autonomously: (1) performs system activation and check-out; (2) searches for and acquires the target; (3) plans and executes a rendezvous while continuously tracking the target; (4) avoids stationary and moving obstacles; (5) reaches for and grapples the target; (6) returns to transfer the object; and (7) returns to base

    Kinematics and Robot Design II (KaRD2019) and III (KaRD2020)

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    This volume collects papers published in two Special Issues “Kinematics and Robot Design II, KaRD2019” (https://www.mdpi.com/journal/robotics/special_issues/KRD2019) and “Kinematics and Robot Design III, KaRD2020” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2020), which are the second and third issues of the KaRD Special Issue series hosted by the open access journal robotics.The KaRD series is an open environment where researchers present their works and discuss all topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. It aims at being an established reference for researchers in the field as other serial international conferences/publications are. Even though the KaRD series publishes one Special Issue per year, all the received papers are peer-reviewed as soon as they are submitted and, if accepted, they are immediately published in MDPI Robotics. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”.KaRD2019 together with KaRD2020 received 22 papers and, after the peer-review process, accepted only 17 papers. The accepted papers cover problems related to theoretical/computational kinematics, to biomedical engineering and to other design/applicative aspects

    Man-machine cooperation in advanced teleoperation

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    Teleoperation experiments at JPL have shown that advanced features in a telerobotic system are a necessary condition for good results, but that they are not sufficient to assure consistently good performance by the operators. Two or three operators are normally used during training and experiments to maintain the desired performance. An alternative to this multi-operator control station is a man-machine interface embedding computer programs that can perform some of the operator's functions. In this paper we present our first experiments with these concepts, in which we focused on the areas of real-time task monitoring and interactive path planning. In the first case, when performing a known task, the operator has an automatic aid for setting control parameters and camera views. In the second case, an interactive path planner will rank different path alternatives so that the operator will make the correct control decision. The monitoring function has been implemented with a neural network doing the real-time task segmentation. The interactive path planner was implemented for redundant manipulators to specify arm configurations across the desired path and satisfy geometric, task, and performance constraints

    Motion Planning for the On-orbit Grasping of a Non-cooperative Target Satellite with Collision Avoidance

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    A method for grasping a tumbling noncooperative target is presented, which is based on nonlinear optimization and collision avoidance. Motion constraints on the robot joints as well as on the end-effector forces are considered. Cost functions of interest address the robustness of the planned solutions during the tracking phase as well as actuation energy. The method is applied in simulation to different operational scenarios

    The development test flight of the flight telerobotic servicer

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    The Development Test Flight (DTF-1) is the first of two shuttle flights to test operations of the Flight Telerobotic Servicer (FTS) in space and to demonstrate its capabilities in performing tasks for Space Station Freedom. The DTF-1 system, which Martin Marietta Astronautics Group is designing and building for the Goddard Space Flight Center, will be flown in December, 1991, as an attached payload on the shuttle. The design of the DTF-1 system, the tests to be performed, and the data to be gathered are discussed

    Analysis of dual-gripper manipulators and finite element analysis of the flexible laminated hose for underground storage tank cleanup

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    The second generation long-reach manipulator - the dual-gripper Phase 3 Remote Tool Delivery (RTD) system has been developed to retrieve radioactive waste from underground storage tanks with internal structural members. The RTD is equipped with two grippers, one at each end of the system, to grasp the structural member. A vertical translation mechanism is also added to the system that enables the vertical motion inside the tank. This special feature provides greater dexterity and flexibility. Two operating open-chain configurations are considered and modeled. The first configuration is that gripper 1 grasps the structural member and gripper 2 is free to perform a designated task. The other configuration is that gripper 2 grasps the structural member and gripper 1 is free to move. The kinematics, dynamics and simulation of the system are emphasized. Finite Element Analysis (FEA) of the flexible laminated hose used to convey radioactive waste materials was investigated to learn about its structural behavior. The hose is considered relatively fixed at one end (the outlet) and subjected to different loading conditions at the inlet. Liquid (mixture of water and sludge) with high viscosity is sucked through the hose using a vacuum pressure. The software package employed for FEA is ANSYS 5.2. A total of 200 cases, with different X, Y and Z loading conditions at the inlet, for the hose under the consideration with or without vacuum pressure have been analyzed. Numerical results and the ANSYS graphic outputs provided for each case include the deformation, stress distribution and strain distribution throughout the hose

    A Mechatronic Perspective on Robotic Arms and End-Effectors

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    Adaptive Evolving Strategy for Dextrous Robotic Manipulation

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    A robot task can be represented as a set of trajectories conformed by a sequence of poses. In this way it is possible to teach a mobile robot to accomplish a manipulation task, and also to reproduce it. Nevertheless robot navigation may normally introduce inaccuracies in localization due to natural events as wheel-slides, causing a mismatch between the end-effector and the objects or tools the robot is supposed to interact with. We propose an algorithm for adapting manipulation trajectories for different locations. The adaptation is achieved by optimizing in position, orientation and energy consumption. The approach is built over the basis of Evolution Strategies, and only uses forward kinematics permitting to avoid all the inconveniences that inverse kinematics imply, as well as convergence problems in singular kinematic configurations. Manipulation paths generated with this algorithm can achieve optimal performance, sometimes even improving original path smoothness. Experimental results are presented to verify the algorithm.The research leading to these results has received funding from the RoboCity2030-II-CM project (S2009/DPI-1559), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU.Publicad
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