208 research outputs found

    Towards Reuse and Recycling of Lithium-ion Batteries: Tele-robotics for Disassembly of Electric Vehicle Batteries

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    Disassembly of electric vehicle batteries is a critical stage in recovery, recycling and re-use of high-value battery materials, but is complicated by limited standardisation, design complexity, compounded by uncertainty and safety issues from varying end-of-life condition. Telerobotics presents an avenue for semi-autonomous robotic disassembly that addresses these challenges. However, it is suggested that quality and realism of the user's haptic interactions with the environment is important for precise, contact-rich and safety-critical tasks. To investigate this proposition, we demonstrate the disassembly of a Nissan Leaf 2011 module stack as a basis for a comparative study between a traditional asymmetric haptic-'cobot' master-slave framework and identical master and slave cobots based on task completion time and success rate metrics. We demonstrate across a range of disassembly tasks a time reduction of 22%-57% is achieved using identical cobots, yet this improvement arises chiefly from an expanded workspace and 1:1 positional mapping, and suffers a 10-30% reduction in first attempt success rate. For unbolting and grasping, the realism of force feedback was comparatively less important than directional information encoded in the interaction, however, 1:1 force mapping strengthened environmental tactile cues for vacuum pick-and-place and contact cutting tasks.Comment: 21 pages, 12 figures, Submitted to Frontiers in Robotics and AI; Human-Robot Interactio

    Multi-robot cooperative platform : a task-oriented teleoperation paradigm

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    This thesis proposes the study and development of a teleoperation system based on multi-robot cooperation under the task oriented teleoperation paradigm: Multi-Robot Cooperative Paradigm, MRCP. In standard teleoperation, the operator uses the master devices to control the remote slave robot arms. These arms reproduce the desired movements and perform the task. With the developed work, the operator can virtually manipulate an object. MRCP automatically generates the arms orders to perform the task. The operator does not have to solve situations arising from possible restrictions that the slave arms may have. The research carried out is therefore aimed at improving the accuracy teleoperation tasks in complex environments, particularly in the field of robot assisted minimally invasive surgery. This field requires patient safety and the workspace entails many restrictions to teleoperation. MRCP can be defined as a platform composed of several robots that cooperate automatically to perform a teleoperated task, creating a robotic system with increased capacity (workspace volume, accessibility, dexterity ...). The cooperation is based on transferring the task between robots when necessary to enable a smooth task execution. The MRCP control evaluates the suitability of each robot to continue with the ongoing task and the optimal time to execute a task transfer between the current selected robot and the best candidate to continue with the task. From the operator¿s point of view, MRCP provides an interface that enables the teleoperation though the task-oriented paradigm: operator orders are translated into task actions instead of robot orders. This thesis is structured as follows: The first part is dedicated to review the current solutions in the teleoperation of complex tasks and compare them with those proposed in this research. The second part of the thesis presents and reviews in depth the different evaluation criteria to determine the suitability of each robot to continue with the execution of a task, considering the configuration of the robots and emphasizing the criterion of dexterity and manipulability. The study reviews the different required control algorithms to enable the task oriented telemanipulation. This proposed teleoperation paradigm is transparent to the operator. Then, the Thesis presents and analyses several experimental results using MRCP in the field of minimally invasive surgery. These experiments study the effectiveness of MRCP in various tasks requiring the cooperation of two hands. A type task is used: a suture using minimally invasive surgery technique. The analysis is done in terms of execution time, economy of movement, quality and patient safety (potential damage produced by undesired interaction between the tools and the vital tissues of the patient). The final part of the thesis proposes the implementation of different virtual aids and restrictions (guided teleoperation based on haptic visual and audio feedback, protection of restricted workspace regions, etc.) using the task oriented teleoperation paradigm. A framework is defined for implementing and applying a basic set of virtual aids and constraints within the framework of a virtual simulator for laparoscopic abdominal surgery. The set of experiments have allowed to validate the developed work. The study revealed the influence of virtual aids in the learning process of laparoscopic techniques. It has also demonstrated the improvement of learning curves, which paves the way for its implementation as a methodology for training new surgeons.Aquesta tesi doctoral proposa l'estudi i desenvolupament d'un sistema de teleoperació basat en la cooperació multi-robot sota el paradigma de la teleoperació orientada a tasca: Multi-Robot Cooperative Paradigm, MRCP. En la teleoperació clàssica, l'operador utilitza els telecomandaments perquè els braços robots reprodueixin els seus moviments i es realitzi la tasca desitjada. Amb el treball realitzat, l'operador pot manipular virtualment un objecte i és mitjançant el MRCP que s'adjudica a cada braç les ordres necessàries per realitzar la tasca, sense que l'operador hagi de resoldre les situacions derivades de possibles restriccions que puguin tenir els braços executors. La recerca desenvolupada està doncs orientada a millorar la teleoperació en tasques de precisió en entorns complexos i, en particular, en el camp de la cirurgia mínimament invasiva assistida per robots. Aquest camp imposa condicions de seguretat del pacient i l'espai de treball comporta moltes restriccions a la teleoperació. MRCP es pot definir com a una plataforma formada per diversos robots que cooperen de forma automàtica per dur a terme una tasca teleoperada, generant un sistema robòtic amb capacitats augmentades (volums de treball, accessibilitat, destresa,...). La cooperació es basa en transferir la tasca entre robots a partir de determinar quin és aquell que és més adequat per continuar amb la seva execució i el moment òptim per realitzar la transferència de la tasca entre el robot actiu i el millor candidat a continuar-la. Des del punt de vista de l'operari, MRCP ofereix una interfície de teleoperació que permet la realització de la teleoperació mitjançant el paradigma d'ordres orientades a la tasca: les ordres es tradueixen en accions sobre la tasca en comptes d'estar dirigides als robots. Aquesta tesi està estructurada de la següent manera: Primerament es fa una revisió de l'estat actual de les diverses solucions desenvolupades actualment en el camp de la teleoperació de tasques complexes, comparant-les amb les proposades en aquest treball de recerca. En el segon bloc de la tesi es presenten i s'analitzen a fons els diversos criteris per determinar la capacitat de cada robot per continuar l'execució d'una tasca, segons la configuració del conjunt de robots i fent especial èmfasi en el criteri de destresa i manipulabilitat. Seguint aquest estudi, es presenten els diferents processos de control emprats per tal d'assolir la telemanipulació orientada a tasca de forma transparent a l'operari. Seguidament es presenten diversos resultats experimentals aplicant MRCP al camp de la cirurgia mínimament invasiva. En aquests experiments s'estudia l'eficàcia de MRCP en diverses tasques que requereixen de la cooperació de dues mans. S'ha escollit una tasca tipus: sutura amb tècnica de cirurgia mínimament invasiva. L'anàlisi es fa en termes de temps d'execució, economia de moviment, qualitat i seguretat del pacient (potencials danys causats per la interacció no desitjada entre les eines i els teixits vitals del pacient). Finalment s'ha estudiat l'ús de diferents ajudes i restriccions virtuals (guiat de la teleoperació via retorn hàptic, visual o auditiu, protecció de regions de l'espai de treball, etc) dins el paradigma de teleoperació orientada a tasca. S'ha definint un marc d'aplicació base i implementant un conjunt de restriccions virtuals dins el marc d'un simulador de cirurgia laparoscòpia abdominal. El conjunt d'experiments realitzats han permès validar el treball realitzat. Aquest estudi ha permès determinar la influencia de les ajudes virtuals en el procés d'aprenentatge de les tècniques laparoscòpiques. S'ha evidenciat una millora en les corbes d'aprenentatge i obre el camí a la seva implantació com a metodologia d'entrenament de nous cirurgians.Postprint (published version

    The Shape of Damping: Optimizing Damping Coefficients to Improve Transparency on Bilateral Telemanipulation

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    This thesis presents a novel optimization-based passivity control algorithm for hapticenabled bilateral teleoperation systems involving multiple degrees of freedom. In particular, in the context of energy-bounding control, the contribution focuses on the implementation of a passivity layer for an existing time-domain scheme, ensuring optimal transparency of the interaction along subsets of the environment space which are preponderant for the given task, while preserving the energy bounds required for passivity. The involved optimization problem is convex and amenable to real-time implementation. The effectiveness of the proposed design is validated via an experiment performed on a virtual teleoperated environment. The interplay between transparency and stability is a critical aspect in haptic-enabled bilateral teleoperation control. While it is important to present the user with the true impedance of the environment, destabilizing factors such as time delays, stiff environments, and a relaxed grasp on the master device may compromise the stability and safety of the system. Passivity has been exploited as one of the the main tools for providing sufficient conditions for stable teleoperation in several controller design approaches, such as the scattering algorithm, timedomain passivity control, energy bounding algorithm, and passive set position modulation. In this work it is presented an innovative energy-based approach, which builds upon existing time-domain passivity controllers, improving and extending their effectiveness and functionality. The set of damping coefficients are prioritized in each degree of freedom, the resulting transparency presents a realistic force feedback in comparison to the other directions. Thus, the prioritization takes effect using a quadratic programming algorithm to find the optimal values for the damping. Finally, the energy tanks approach on passivity control is a solution used to ensure stability in a system for robotics bilateral manipulation. The bilateral telemanipulation must maintain the principle of passivity in all moments to preserve the system\u2019s stability. This work presents a brief introduction to haptic devices as a master component on the telemanipulation chain; the end effector in the slave side is a representation of an interactive object within an environment having a force sensor as feedback signal. The whole interface is designed into a cross-platform framework named ROS, where the user interacts with the system. Experimental results are presented

    Sharing and Trading in a Human-Robot System

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    Human-robot interaction for telemanipulation by small unmanned aerial systems

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    This dissertation investigated the human-robot interaction (HRI) for the Mission Specialist role in a telemanipulating unmanned aerial system (UAS). The emergence of commercial unmanned aerial vehicle (UAV) platforms transformed the civil and environmental engineering industries through applications such as surveying, remote infrastructure inspection, and construction monitoring, which normally use UAVs for visual inspection only. Recent developments, however, suggest that performing physical interactions in dynamic environments will be important tasks for future UAS, particularly in applications such as environmental sampling and infrastructure testing. In all domains, the availability of a Mission Specialist to monitor the interaction and intervene when necessary is essential for successful deployments. Additionally, manual operation is the default mode for safety reasons; therefore, understanding Mission Specialist HRI is important for all small telemanipulating UAS in civil engineering, regardless of system autonomy and application. A 5 subject exploratory study and a 36 subject experimental study were conducted to evaluate variations of a dedicated, mobile Mission Specialist interface for aerial telemanipulation from a small UAV. The Shared Roles Model was used to model the UAS human-robot team, and the Mission Specialist and Pilot roles were informed by the current state of practice for manipulating UAVs. Three interface camera view designs were tested using a within-subjects design, which included an egocentric view (perspective from the manipulator), exocentric view (perspective from the UAV), and mixed egocentric-exocentric view. The experimental trials required Mission Specialist participants to complete a series of tasks with physical, visual, and verbal requirements. Results from these studies found that subjects who preferred the exocentric condition performed tasks 50% faster when using their preferred interface; however, interface preferences did not affect performance for participants who preferred the mixed condition. This result led to a second finding that participants who preferred the exocentric condition were distracted by the egocentric view during the mixed condition, likely caused by cognitive tunneling, and the data suggest tradeoffs between performance improvements and attentional costs when adding information in the form of multiple views to the Mission Specialist interface. Additionally, based on this empirical evaluation of multiple camera views, the exocentric view was recommended for use in a dedicated Mission Specialist telemanipulation interface. Contributions of this thesis include: i) conducting the first focused HRI study of aerial telemanipulation, ii) development of an evaluative model for telemanipulation performance, iii) creation of new recommendations for aerial telemanipulation interfacing, and iv) contribution of code, hardware designs, and system architectures to the open-source UAV community. The evaluative model provides a detailed framework, a complement to the abstraction of the Shared Roles Model, that can be used to measure the effects of changes in the system, environment, operators, and interfacing factors on performance. The practical contributions of this work will expedite the use of manipulating UAV technologies by scientists, researchers, and stakeholders, particularly those in civil engineering, who will directly benefit from improved manipulating UAV performance

    Human factors issues in telerobotic decommissioning of legacy nuclear facilities

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    This thesis investigates the problems of enabling human workers to control remote robots, to achieve decommissioning of contaminated nuclear facilities, which are hazardous for human workers to enter. The mainstream robotics literature predominantly reports novel mechanisms and novel control algorithms. In contrast, this thesis proposes experimental methodologies for objectively evaluating the performance of both a robot and its remote human operator, when challenged with carrying out industrially relevant remote manipulation tasks. Initial experiments use a variety of metrics to evaluate the performance of human test-subjects. Results show that: conventional telemanipulation is extremely slow and difficult; metrics for usability of such technology can be conflicting and hard to interpret; aptitude for telemanipulation varies significantly between individuals; however such aptitude may be rendered predictable by using simple spatial awareness tests. Additional experiments suggest that autonomous robotics methods (e.g. vision-guided grasping) can significantly assist the operator. A novel approach to telemanipulation is proposed, in which an ``orbital camera`` enables the human operator to select arbitrary views of the scene, with the robot's motions transformed into the orbital view coordinate frame. This approach is useful for overcoming the severe depth perception problems of conventional fixed camera views. Finally, a novel computer vision algorithm is proposed for target tracking. Such an algorithm could be used to enable an unmanned aerial vehicle (UAV) to fixate on part of the workspace, e.g. a manipulated object, to provide the proposed orbital camera view

    Exploring Robot Teleoperation in Virtual Reality

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    This thesis presents research on VR-based robot teleoperation with a focus on remote environment visualisation in virtual reality, the effects of remote environment reconstruction scale in virtual reality on the human-operator's ability to control the robot and human-operator's visual attention patterns when teleoperating a robot from virtual reality. A VR-based robot teleoperation framework was developed, it is compatible with various robotic systems and cameras, allowing for teleoperation and supervised control with any ROS-compatible robot and visualisation of the environment through any ROS-compatible RGB and RGBD cameras. The framework includes mapping, segmentation, tactile exploration, and non-physically demanding VR interface navigation and controls through any Unity-compatible VR headset and controllers or haptic devices. Point clouds are a common way to visualise remote environments in 3D, but they often have distortions and occlusions, making it difficult to accurately represent objects' textures. This can lead to poor decision-making during teleoperation if objects are inaccurately represented in the VR reconstruction. A study using an end-effector-mounted RGBD camera with OctoMap mapping of the remote environment was conducted to explore the remote environment with fewer point cloud distortions and occlusions while using a relatively small bandwidth. Additionally, a tactile exploration study proposed a novel method for visually presenting information about objects' materials in the VR interface, to improve the operator's decision-making and address the challenges of point cloud visualisation. Two studies have been conducted to understand the effect of virtual world dynamic scaling on teleoperation flow. The first study investigated the use of rate mode control with constant and variable mapping of the operator's joystick position to the speed (rate) of the robot's end-effector, depending on the virtual world scale. The results showed that variable mapping allowed participants to teleoperate the robot more effectively but at the cost of increased perceived workload. The second study compared how operators used a virtual world scale in supervised control, comparing the virtual world scale of participants at the beginning and end of a 3-day experiment. The results showed that as operators got better at the task they as a group used a different virtual world scale, and participants' prior video gaming experience also affected the virtual world scale chosen by operators. Similarly, the human-operator's visual attention study has investigated how their visual attention changes as they become better at teleoperating a robot using the framework. The results revealed the most important objects in the VR reconstructed remote environment as indicated by operators' visual attention patterns as well as their visual priorities shifts as they got better at teleoperating the robot. The study also demonstrated that operators’ prior video gaming experience affects their ability to teleoperate the robot and their visual attention behaviours

    Intent-Recognition-Based Traded Control for Telerobotic Assembly over High-Latency Telemetry

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    As we deploy robotic manipulation systems into unstructured real-world environments, the tasks which those robots are expected to perform grow very quickly in complexity. These tasks require a greater number of possible actions, more variable environmental conditions, and larger varieties of objects and materials which need to be manipulated. This in turn leads to a greater number of ways in which elements of a task can fail. When the cost of task failure is high, such as in the case of surgery or on-orbit robotic interventions, effective and efficient task recovery is essential. Despite ever-advancing capabilities, however, the current and near future state-of-the-art in fully autonomous robotic manipulation is still insufficient for many tasks in these critical applications. Thus, successful application of robotic manipulation in many application domains still necessitates a human operator to directly teleoperate the robots over some communications infrastructure. However, any such infrastructure always incurs some unavoidable round-trip telemetry latency depending on the distances involved and the type of remote environment. While direct teleoperation is appropriate when a human operator is physically close to the robots being controlled, there are still many applications in which such proximity is infeasible. In applications which require a robot to be far from its human operator, this latency can approach the speed of the relevant task dynamics, and performing the task with direct telemanipulation can become increasingly difficult, if not impossible. For example, round-trip delays for ground-controlled on-orbit robotic manipulation can reach multiple seconds depending on the infrastructure used and the location of the remote robot. The goal of this thesis is to advance the state-of-the art in semi-autonomous telemanipulation under multi-second round-trip communications latency between a human operator and remote robot in order to enable more telerobotic applications. We propose a new intent-recognition-based traded control (IRTC) approach which automatically infers operator intent and executes task elements which the human operator would otherwise be unable to perform. What makes our approach more powerful than the current approaches is that we prioritize preserving the operator's direct manual interaction with the remote environment while only trading control over to an autonomous subsystem when the operator-local intent recognition system automatically determines what the operator is trying to accomplish. This enables operators to perform unstructured and a priori unplanned actions in order to quickly recover from critical task failures. Furthermore, this thesis also describes a methodology for introducing and improving semi-autonomous control in critical applications. Specifically, this thesis reports (1) the demonstration of a prototype system for IRTC-based grasp assistance in the context of transatlantic telemetry delays, (2) the development of a systems framework for IRTC in semi-autonomous telemanipulation, and (3) an evaluation of the usability and efficacy of that framework with an increasingly complex assembly task. The results from our human subjects experiments show that, when incorporated with sufficient lower-level capabilities, IRTC is a promising approach to extend the reach and capabilities of on-orbit telerobotics and future in-space operations
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