5,276 research outputs found
a computer assisted robotic platform for vascular procedures exploiting 3d us based tracking
AbstractBackground: Cardiovascular diseases are the first cause of death globally: an estimated 17.5 million people died in 2012. By combining the benefits of magnetic navigation and ultrasound (US) imaging, the authors proposed a robotic platform (i.e. the MicroVAST platform) for intravascular medical procedures.Methods: A 3D imaging US-based tracking algorithm is implemented for the navigation of a magnetic-dragged soft-tethered device. Tests were performed to evaluate the algorithm in terms of tracking error and precision of locomotion.Results: The 3D imaging US-based algorithm tracked the endovascular device with an error of 6.4 ± 2.8 pixels and a mean displacement between the endovascular device and the preoperative path of 13.6 ± 4.5 mm (computational time of 12.2 ± 1.5 ms and 30.7 ± 6.1 matched features).Conclusions: The MicroVAST platform includes innovative solutions for navigation allowing for an assisted magnetic locomotion of medical devices in the cardiovascular district by combining a 3D ima..
An Annotated Corpus for Machine Reading of Instructions in Wet Lab Protocols
We describe an effort to annotate a corpus of natural language instructions
consisting of 622 wet lab protocols to facilitate automatic or semi-automatic
conversion of protocols into a machine-readable format and benefit biological
research. Experimental results demonstrate the utility of our corpus for
developing machine learning approaches to shallow semantic parsing of
instructional texts. We make our annotated Wet Lab Protocol Corpus available to
the research community
A flexible sensor technology for the distributed measurement of interaction pressure
We present a sensor technology for the measure of the physical human-robot interaction pressure developed in the last years at Scuola Superiore Sant'Anna. The system is composed of flexible matrices of opto-electronic sensors covered by a soft silicone cover. This sensory system is completely modular and scalable, allowing one to cover areas of any sizes and shapes, and to measure different pressure ranges. In this work we present the main application areas for this technology. A first generation of the system was used to monitor human-robot interaction in upper- (NEUROExos; Scuola Superiore Sant'Anna) and lower-limb (LOPES; University of Twente) exoskeletons for rehabilitation. A second generation, with increased resolution and wireless connection, was used to develop a pressure-sensitive foot insole and an improved human-robot interaction measurement systems. The experimental characterization of the latter system along with its validation on three healthy subjects is presented here for the first time. A perspective on future uses and development of the technology is finally drafted
Intelligent robust control of redundant smart robotic arm Pt I: Soft computing KB optimizer - deep machine learning IT
Redundant robotic arm models as a control object discussed. Background of computational intelligence IT based on soft computing optimizer of knowledge base in smart robotic manipulators introduced. Soft computing optimizer is the toolkit of deep machine learning SW platform with optimal fuzzy neural network structure. The methods for development and design technology of intelligent control systems based on the soft computing optimizer presented in this Part 1 allow one to implement the principle of design an optimal intelligent control systems with a maximum reliability and controllability level of a complex control object under conditions of uncertainty in the source data, and in the presence of stochastic noises of various physical and statistical characters. The knowledge bases formed with the application of a soft computing optimizer produce robust control laws for the schedule of time dependent coefficient gains of conventional PID controllers for a wide range of external perturbations and are maximally insensitive to random variations of the structure of control object. The robustness of control laws is achieved by application a vector fitness function for genetic algorithm, whose one component describes the physical principle of minimum production of generalized entropy both in the control object and the control system, and the other components describe conventional control objective functionals such as minimum control error, etc. The application of soft computing technologies (Part I) for the development a robust intelligent control system that solving the problem of precision positioning redundant (3DOF and 7 DOF) manipulators considered. Application of quantum soft computing in robust intelligent control of smart manipulators in Part II described
A Variable Stiffness Robotic Probe for Soft Tissue Palpation
During abdominal palpation diagnosis, a medical practitioner would change the stiffness of their fingers in order to improve the detection of hard nodules or abnormalities in soft tissue to maximize the haptic information gain via tendons. Our recent experiments using a controllable stiffness robotic probe representing a human finger also confirmed that such stiffness control in the finger can enhance the accuracy of detecting hard nodules in soft tissue. However, the limited range of stiffness achieved by the antagonistic springs variable stiffness joint subject to size constraints made it unsuitable for a wide range of physical examination scenarios spanning from breast to abdominal examination. In this letter, we present a new robotic probe based on a variable lever mechanism able to achieve stiffness ranging from 0.64 to 1.06 N·m/rad that extends the maximum stiffness by around 16 times and the stiffness range by 33 times. This letter presents the mechanical model of the novel probe, the finite element simulation as well as experimental characterization of the stiffness response for lever actuation.This work was supported by The United Kingdom Engineering and Physical Sciences Research Council under MOTION Grant EP/N03211X/2
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A Lower Limb Prosthesis with Active Alignment for Reduced Limb Loading
Over the past decade, the growing field of robotics has created new possibilities in lower limb prostheses. The focus of these new prostheses has been replicating the dynamics of the lost limb in order to restore gait of individuals with lower limb amputations to healthy norms. This places demanding loads on the residual limb. Compensation by the rest of body is high, causes overloading of intact joints and can lead to deterioration of mobility and overall health. Abnormalities remain present in the person’s gait, stemming from the loading of soft tissue and the altered anatomy of the affected limb. In this dissertation, an experimental prosthesis is developed with systematic, simulation based techniques. Kinematics and kinetics of the prosthesis design are altered in order to actively realign the limb in relation to the center of pressure during stance, allowing positive power to be generated by the prosthesis while actively reducing the magnitude of the sagittal moment transferred to the residual limb. Initial findings show that during walking with the experimental device compared to a daily use prosthesis, peak pressures on the residual limb are lowered by over 10% while maintaining walking speed
Compliant aerial manipulation.
The aerial manipulation is a research field which proposes the integration of robotic manipulators in aerial platforms, typically multirotors – widely known as “drones” – or autonomous helicopters. The development of this technology is motivated by the convenience to reduce the time, cost and risk associated to the execution of certain operations or tasks in high altitude areas or difficult access workspaces. Some illustrative application examples are the detection and insulation of leaks in pipe structures in chemical plants, repairing the corrosion in the blades of wind turbines, the maintenance of power lines, or the installation and retrieval of sensor devices in polluted areas. Although nowadays it is possible to find a wide variety of commercial multirotor platforms with payloads from a few gramps up to several kilograms, and flight times around thirty minutes, the development of an aerial manipulator is still a technological challenge due to the strong requirements relative to the design of the manipulator in terms of very low weight, low inertia, dexterity, mechanical robustness and control.
The main contribution of this thesis is the design, development and experimental validation of several prototypes of lightweight (<2 kg) and compliant manipulators to be integrated in multirotor platforms, including human-size dual arm systems, compliant joint arms equipped with human-like finger modules for grasping, and long reach aerial manipulators. Since it is expected that the aerial manipulator is capable to execute inspection and maintenance tasks in a similar way a human operator would do, this thesis proposes a bioinspired design approach, trying to replicate the human arm in terms of size, kinematics, mass distribution, and compliance. This last feature is actually one of the key concepts developed and exploited in this work. Introducing a flexible element such as springs or elastomers between the servos and the links extends the capabilities of the manipulator, allowing the estimation and control of the torque/force, the detection of impacts and overloads, or the localization of obstacles by contact. It also improves safety and efficiency of the manipulator, especially during the operation on flight or in grabbing situations, where the impacts and contact forces may damage the manipulator or destabilize the aerial platform. Unlike most industrial manipulators, where force-torque control is possible at control rates above 1 kHz, the servo actuators typically employed in the development of aerial manipulators present important technological limitations: no torque feedback nor control, only position (and in some models, speed) references, low update rates (<100 Hz), and communication delays. However, these devices are still the best solution due to their high torque to weight ratio, low cost, compact design, and easy assembly and integration. In order to cope with these limitations, the compliant joint arms presented here estimate and control the wrenches from the deflection of the spring-lever transmission mechanism introduced in the joints, measured at joint level with encoders or potentiometers, or in the Cartesian space employing vision sensors. Note that in the developed prototypes, the maximum joint deflection is around 25 degrees, which corresponds to a deviation in the position of the end effector around 20 cm for a human-size arm. The capabilities and functionalities of the manipulators have been evaluated in fixed base test-bench firstly, and then in outdoor flight tests, integrating the arms in different commercial hexarotor platforms. Frequency characterization, position/force/impedance control, bimanual grasping, arm teleoperation, payload mass estimation, or contact-based obstacle localization are some of the experiments presented in this thesis that validate the developed prototypes.La manipulaciĂłn aĂ©rea es un campo de investigaciĂłn que propone la integraciĂłn de manipuladores robĂłticos in plataformas aĂ©reas, tĂpicamente multirotores – comĂşnmente conocidos como “drones” – o helicĂłpteros autĂłnomos. El desarrollo de esta tecnologĂa está motivada por la conveniencia de reducir el tiempo, coste y riesgo asociado a la ejecuciĂłn de ciertas operaciones o tareas en áreas de gran altura o espacios de trabajo de difĂcil acceso. Algunos ejemplos ilustrativos de aplicaciones son la detecciĂłn y aislamiento de fugas en estructura de tuberĂas en plantas quĂmicas, la reparaciĂłn de la corrosiĂłn en las palas de aerogeneradores, el mantenimiento de lĂneas elĂ©ctricas, o la instalaciĂłn y recuperaciĂłn de sensores en zonas contaminadas. Aunque hoy en dĂa es posible encontrar una amplia variedad de plataformas multirotor comerciales con cargas de pago desde unos pocos gramos hasta varios kilogramos, y tiempo de vuelo entorno a treinta minutos, el desarrollo de los manipuladores aĂ©reos es todavĂa un desafĂo tecnolĂłgico debido a los exigentes requisitos relativos al diseño del manipulador en tĂ©rminos de muy bajo peso, baja inercia, destreza, robustez mecánica y control.
La contribuciĂłn principal de esta tesis es el diseño, desarrollo y validaciĂłn experimental de varios prototipos de manipuladores de bajo peso (<2 kg) con capacidad de acomodaciĂłn (“compliant”) para su integraciĂłn en plataformas aĂ©reas multirotor, incluyendo sistemas bi-brazo de tamaño humano, brazos robĂłticos de articulaciones flexibles con dedos antropomĂłrficos para agarre, y manipuladores aĂ©reos de largo alcance. Puesto que se prevĂ© que el manipulador aĂ©reo sea capaz de ejecutar tareas de inspecciĂłn y mantenimiento de forma similar a como lo harĂa un operador humano, esta tesis propone un enfoque de diseño bio-inspirado, tratando de replicar el brazo humano en cuanto a tamaño, cinemática, distribuciĂłn de masas y flexibilidad. Esta caracterĂstica es de hecho uno de los conceptos clave desarrollados y utilizados en este trabajo. Al introducir un elemento elástico como los muelles o elastĂłmeros entre el los actuadores y los enlaces se aumenta las capacidades del manipulador, permitiendo la estimaciĂłn y control de las fuerzas y pares, la detecciĂłn de impactos y sobrecargas, o la localizaciĂłn de obstáculos por contacto. Además mejora la seguridad y eficiencia del manipulador, especialmente durante las operaciones en vuelo, donde los impactos y fuerzas de contacto pueden dañar el manipulador o desestabilizar la plataforma aĂ©rea. A diferencia de la mayorĂa de manipuladores industriales, donde el control de fuerzas y pares es posible a tasas por encima de 1 kHz, los servo motores tĂpicamente utilizados en el desarrollo de manipuladores aĂ©reos presentan importantes limitaciones tecnolĂłgicas: no hay realimentaciĂłn ni control de torque, sĂłlo admiten referencias de posiciĂłn (o bien de velocidad), y presentan retrasos de comunicaciĂłn. Sin embargo, estos dispositivos son todavĂa la mejor soluciĂłn debido al alto ratio de torque a peso, por su bajo peso, diseño compacto y facilidad de ensamblado e integraciĂłn. Para suplir estas limitaciones, los brazos robĂłticos flexibles presentados aquĂ permiten estimar y controlar las fuerzas a partir de la deflexiĂłn del mecanismo de muelle-palanca introducido en las articulaciones, medida a nivel articular mediante potenciĂłmetros o codificadores, o en espacio Cartesiano mediante sensores de visiĂłn. TĂłmese como referencia que en los prototipos desarrollados la máxima deflexiĂłn articular es de unos 25 grados, lo que corresponde a una desviaciĂłn de posiciĂłn en torno a 20 cm en el efector final para un brazo de tamaño humano. Las capacidades y funcionalidades de estos manipuladores se han evaluado en base fija primero, y luego en vuelos en exteriores, integrando los brazos en diferentes plataformas hexartor comerciales. CaracterizaciĂłn frecuencial, control de posiciĂłn/fuerza/impedancia, agarre bimanual, teleoperaciĂłn de brazos, estimaciĂłn de carga, o la localizaciĂłn de obstáculos mediante contacto son algunos de los experimentos presentados en esta tesis para validar los prototipos desarrollados por el auto
A Model-Driven Engineering Approach for ROS using Ontological Semantics
This paper presents a novel ontology-driven software engineering approach for
the development of industrial robotics control software. It introduces the
ReApp architecture that synthesizes model-driven engineering with semantic
technologies to facilitate the development and reuse of ROS-based components
and applications. In ReApp, we show how different ontological classification
systems for hardware, software, and capabilities help developers in discovering
suitable software components for their tasks and in applying them correctly.
The proposed model-driven tooling enables developers to work at higher
abstraction levels and fosters automatic code generation. It is underpinned by
ontologies to minimize discontinuities in the development workflow, with an
integrated development environment presenting a seamless interface to the user.
First results show the viability and synergy of the selected approach when
searching for or developing software with reuse in mind.Comment: Presented at DSLRob 2015 (arXiv:1601.00877), Stefan Zander, Georg
Heppner, Georg Neugschwandtner, Ramez Awad, Marc Essinger and Nadia Ahmed: A
Model-Driven Engineering Approach for ROS using Ontological Semantic
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