Development of an Autonomous Robot for Gas Storage Spheres Inspection

Inspection for corrosion of gas storage spheres at the welding seam lines must be done periodically. Until now this inspection is being done manually and has a high cost associated to it and a high risk of inspection personel injuries. The Brazilian Petroleum Company, Petrobras, is seeking cost reduction and personel safety by the use of autonomous robot technology. This paper presents the development of a robot capable of autonomously follow a welding line and transporting corrosion measurement sensors. The robot uses a pair of sensors each composed of a laser source and a video camera that allows the estimation of the center of the welding line. The mechanical robot uses four magnetic wheels to adhere to the sphere's surface and was constructed in a way that always three wheels are in contact with the sphere's metallic surface which guarantees enough magnetic atraction to hold the robot in the sphere's surface all the time. Additionally, an independently actuated table for attaching the corrosion inspection sensors was included for small position corrections. Tests were conducted at the laboratory and in a real sphere showing the validity of the proposed approach and implementation.

On the use of a low-cost thermal sensor to improve kinect people detection in a mobile robot

[EN]Detecting people is a key capability for robots that operate in populated environments. In this paper, we have adopted a hierarchical approach that combines classifiers created using supervised learning in order to identify whether a person is in the view-scope of the robot or not. Our approach makes use of vision, depth and thermal sensors mounted on top of a mobile platform.

Retraining of interjoint arm coordination after stroke using robot-assisted time-independent functional training

We have developed a haptic-based approach for retraining of interjoint coordination following stroke called time-independent functional training (TIFT) and implemented this mode in the ARMin III robotic exoskeleton. The ARMin III robot was developed by Drs. Robert Riener and Tobias Nef at the Swiss Federal Institute of Technology Zurich (Eidgenossische Technische Hochschule Zurich, or ETH Zurich), in Zurich, Switzerland. In the TIFT mode, the robot maintains arm movements within the proper kinematic trajectory via haptic walls at each joint. These arm movements focus training of interjoint coordination with highly intuitive real-time feedback of performance; arm movements advance within the trajectory only if their movement coordination is correct. In initial testing, 37 nondisabled subjects received a single session of learning of a complex pattern. Subjects were randomized to TIFT or visual demonstration or moved along with the robot as it moved though the pattern (time-dependent [TD] training). We examined visual demonstration to separate the effects of action observation on motor learning from the effects of the two haptic guidance methods. During these training trials, TIFT subjects reduced error and interaction forces between the robot and arm, while TD subject performance did not change. All groups showed significant learning of the trajectory during unassisted recall trials, but we observed no difference in learning between groups, possibly because this learning task is dominated by vision. Further testing in stroke populations is warranted.

A vision-based strategy for autonomous aerial refueling tasks

Autonomous aerial refueling is a key enabling technology for both manned and unmanned aircraft where extended flight duration or range are required. The results presented within this paper offer one potential vision-based sensing solution, together with a unique test environment. A hierarchical visual tracking algorithm based on direct methods is proposed and developed for the purposes of tracking a drogue during the capture stage of autonomous aerial refueling, and of estimating its 3D position. Intended to be applied in real time to a video stream from a single monocular camera mounted on the receiver aircraft, the algorithm is shown to be highly robust, and capable of tracking large, rapid drogue motions within the frame of reference. The proposed strategy has been tested using a complex robotic testbed and with actual flight hardware consisting of a full size probe and drogue. Results show that the vision tracking algorithm can detect and track the drogue at real-time frame rates of more than thirty frames per second, obtaining a robust position estimation even with strong motions and multiple occlusions of the drogue.

A vision based aerial rbot solution for the IARC 2014 by the Technical University of Madrid

The IARC competitions aim at making the state of the art in UAV progress. The 2014 challenge deals mainly with GPS/Laser denied navigation, Robot-Robot interaction and Obstacle avoidance in the setting of a ground robot herding problem. We present in this paper a drone which will take part in this competition. The platform and hardware it is composed of and the software we designed are introduced. This software has three main components: the visual information acquisition, the mapping algorithm and the Aritificial Intelligence mission planner. A statement of the safety measures integrated in the drone and of our efforts to ensure field testing in conditions as close as possible to the challenge?s is also included.

Desarrollo de tecnologías de telemanipulación con alto grado de escalado orientadas a la interacción hombre-robot en entornos nucleares

Esta tesis se centra en desarrollo de tecnologías para la interacción hombre-robot en entornos nucleares de fusión. La problemática principal del sector de fusión nuclear radica en las condiciones ambientales tan extremas que hay en el interior del reactor, y la necesidad de que los equipos cumplan requisitos muy restrictivos para poder aguantar esos niveles de radiación, magnetismo, ultravacío, temperatura... Como no es viable la ejecución de tareas directamente por parte de humanos, habrá que utilizar dispositivos de manipulación remota para llevar a cabo los procesos de operación y mantenimiento. En las instalaciones de ITER es obligatorio tener un entorno controlado de extrema seguridad, que necesita de estándares validados. La definición y uso de protocolos es indispensable para regir su buen funcionamiento. Si nos centramos en la telemanipulación con algo grado de escalado, surge la necesidad de definir protocolos para sistemas abiertos que permitan la interacción entre equipos y dispositivos de diversa índole. En este contexto se plantea la definición del Protocolo de Teleoperación que permita la interconexión entre dispositivos maestros y esclavos de distinta tipología, pudiéndose comunicar bilateralmente entre sí y utilizar distintos algoritmos de control según la tarea a desempeñar. Este protocolo y su interconectividad se han puesto a prueba en la Plataforma Abierta de Teleoperación (P.A.T.) que se ha desarrollado e integrado en la ETSII UPM como una herramienta que permita probar, validar y realizar experimentos de telerrobótica. Actualmente, este Protocolo de Teleoperación se ha propuesto a través de AENOR al grupo ISO de Telerobotics como una solución válida al problema existente y se encuentra bajo revisión. Con el diseño de dicho protocolo se ha conseguido enlazar maestro y esclavo, sin embargo con los niveles de radiación tan altos que hay en ITER la electrónica del controlador no puede entrar dentro del tokamak. Por ello se propone que a través de una mínima electrónica convenientemente protegida se puedan multiplexar las señales de control que van a través del cableado umbilical desde el controlador hasta la base del robot. En este ejercicio teórico se demuestra la utilidad y viabilidad de utilizar este tipo de solución para reducir el volumen y peso del cableado umbilical en cifras aproximadas de un 90%, para ello hay que desarrollar una electrónica específica y con certificación RadHard para soportar los enormes niveles de radiación de ITER. Para este manipulador de tipo genérico y con ayuda de la Plataforma Abierta de Teleoperación, se ha desarrollado un algoritmo que mediante un sensor de fuerza/par y una IMU colocados en la muñeca del robot, y convenientemente protegidos ante la radiación, permiten calcular las fuerzas e inercias que produce la carga, esto es necesario para poder transmitirle al operador unas fuerzas escaladas, y que pueda sentir la carga que manipula, y no otras fuerzas que puedan influir en el esclavo remoto, como ocurre con otras técnicas de estimación de fuerzas. Como el blindaje de los sensores no debe ser grande ni pesado, habrá que destinar este tipo de tecnología a las tareas de mantenimiento de las paradas programadas de ITER, que es cuando los niveles de radiación están en sus valores mínimos. Por otro lado para que el operador sienta lo más fielmente posible la fuerza de carga se ha desarrollado una electrónica que mediante el control en corriente de los motores permita realizar un control en fuerza a partir de la caracterización de los motores del maestro. Además para aumentar la percepción del operador se han realizado unos experimentos que demuestran que al aplicar estímulos multimodales (visuales, auditivos y hápticos) aumenta su inmersión y el rendimiento en la consecución de la tarea puesto que influyen directamente en su capacidad de respuesta. Finalmente, y en referencia a la realimentación visual del operador, en ITER se trabaja con cámaras situadas en localizaciones estratégicas, si bien el humano cuando manipula objetos hace uso de su visión binocular cambiando constantemente el punto de vista adecuándose a las necesidades visuales de cada momento durante el desarrollo de la tarea. Por ello, se ha realizado una reconstrucción tridimensional del espacio de la tarea a partir de una cámara-sensor RGB-D, lo cual nos permite obtener un punto de vista binocular virtual móvil a partir de una cámara situada en un punto fijo que se puede proyectar en un dispositivo de visualización 3D para que el operador pueda variar el punto de vista estereoscópico según sus preferencias. La correcta integración de estas tecnologías para la interacción hombre-robot en la P.A.T. ha permitido validar mediante pruebas y experimentos para verificar su utilidad en la aplicación práctica de la telemanipulación con alto grado de escalado en entornos nucleares de fusión. Abstract This thesis focuses on developing technologies for human-robot interaction in nuclear fusion environments. The main problem of nuclear fusion sector resides in such extreme environmental conditions existing in the hot-cell, leading to very restrictive requirements for equipment in order to deal with these high levels of radiation, magnetism, ultravacuum, temperature... Since it is not feasible to carry out tasks directly by humans, we must use remote handling devices for accomplishing operation and maintenance processes. In ITER facilities it is mandatory to have a controlled environment of extreme safety and security with validated standards. The definition and use of protocols is essential to govern its operation. Focusing on Remote Handling with some degree of escalation, protocols must be defined for open systems to allow interaction among different kind of equipment and several multifunctional devices. In this context, a Teleoperation Protocol definition enables interconnection between master and slave devices from different typologies, being able to communicate bilaterally one each other and using different control algorithms depending on the task to perform. This protocol and its interconnectivity have been tested in the Teleoperation Open Platform (T.O.P.) that has been developed and integrated in the ETSII UPM as a tool to test, validate and conduct experiments in Telerobotics. Currently, this protocol has been proposed for Teleoperation through AENOR to the ISO Telerobotics group as a valid solution to the existing problem, and it is under review. Master and slave connection has been achieved with this protocol design, however with such high radiation levels in ITER, the controller electronics cannot enter inside the tokamak. Therefore it is proposed a multiplexed electronic board, that through suitable and RadHard protection processes, to transmit control signals through an umbilical cable from the controller to the robot base. In this theoretical exercise the utility and feasibility of using this type of solution reduce the volume and weight of the umbilical wiring approximate 90% less, although it is necessary to develop specific electronic hardware and validate in RadHard qualifications in order to handle huge levels of ITER radiation. Using generic manipulators does not allow to implement regular sensors for force feedback in ITER conditions. In this line of research, an algorithm to calculate the forces and inertia produced by the load has been developed using a force/torque sensor and IMU, both conveniently protected against radiation and placed on the robot wrist. Scaled forces should be transmitted to the operator, feeling load forces but not other undesirable forces in slave system as those resulting from other force estimation techniques. Since shielding of the sensors should not be large and heavy, it will be necessary to allocate this type of technology for programmed maintenance periods of ITER, when radiation levels are at their lowest levels. Moreover, the operator perception needs to feel load forces as accurate as possible, so some current control electronics were developed to perform a force control of master joint motors going through a correct motor characterization. In addition to increase the perception of the operator, some experiments were conducted to demonstrate applying multimodal stimuli (visual, auditory and haptic) increases immersion and performance in achieving the task since it is directly correlated with response time. Finally, referring to the visual feedback to the operator in ITER, it is usual to work with 2D cameras in strategic locations, while humans use binocular vision in direct object manipulation, constantly changing the point of view adapting it to the visual needs for performing manipulation during task procedures. In this line a three-dimensional reconstruction of non-structured scenarios has been developed using RGB-D sensor instead of cameras in the remote environment. Thus a mobile virtual binocular point of view could be generated from a camera at a fixed point, projecting stereoscopic images in 3D display device according to operator preferences. The successful integration of these technologies for human-robot interaction in the T.O.P., and validating them through tests and experiments, verify its usefulness in practical application of high scaling remote handling at nuclear fusion environments.

Guidance of robot arms using depth data from RGB-D camera

Image Based Visual Servoing (IBVS) is a robotic control scheme based on vision. This scheme uses only the visual information obtained from a camera to guide a robot from any robot pose to a desired one. However, IBVS requires the estimation of different parameters that cannot be obtained directly from the image. These parameters range from the intrinsic camera parameters (which can be obtained from a previous camera calibration), to the measured distance on the optical axis between the camera and visual features, it is the depth. This paper presents a comparative study of the performance of D-IBVS estimating the depth from three different ways using a low cost RGB-D sensor like Kinect. The visual servoing system has been developed over ROS (Robot Operating System), which is a meta-operating system for robots. The experiments prove that the computation of the depth value for each visual feature improves the system performance.

3D Visual Data-Driven Spatiotemporal Deformations for Non-Rigid Object Grasping Using Robot Hands

Sensing techniques are important for solving problems of uncertainty inherent to intelligent grasping tasks. The main goal here is to present a visual sensing system based on range imaging technology for robot manipulation of non-rigid objects. Our proposal provides a suitable visual perception system of complex grasping tasks to support a robot controller when other sensor systems, such as tactile and force, are not able to obtain useful data relevant to the grasping manipulation task. In particular, a new visual approach based on RGBD data was implemented to help a robot controller carry out intelligent manipulation tasks with flexible objects. The proposed method supervises the interaction between the grasped object and the robot hand in order to avoid poor contact between the fingertips and an object when there is neither force nor pressure data. This new approach is also used to measure changes to the shape of an object’s surfaces and so allows us to find deformations caused by inappropriate pressure being applied by the hand’s fingers. Test was carried out for grasping tasks involving several flexible household objects with a multi-fingered robot hand working in real time. Our approach generates pulses from the deformation detection method and sends an event message to the robot controller when surface deformation is detected. In comparison with other methods, the obtained results reveal that our visual pipeline does not use deformations models of objects and materials, as well as the approach works well both planar and 3D household objects in real time. In addition, our method does not depend on the pose of the robot hand because the location of the reference system is computed from a recognition process of a pattern located place at the robot forearm. The presented experiments demonstrate that the proposed method accomplishes a good monitoring of grasping task with several objects and different grasping configurations in indoor environments.

A modified particle filter for simultaneous robot localization and landmark tracking in an indoor environment

This paper presents the implementation of a modified particle filter for vision-based simultaneous localization and mapping of an autonomous robot in a structured indoor environment. Through this method, artificial landmarks such as multi-coloured cylinders can be tracked with a camera mounted on the robot, and the position of the robot can be estimated at the same time. Experimental results in simulation and in real environments show that this approach has advantages over the extended Kalman filter with ambiguous data association and various levels of odometric noise.

UQ RoboRoos: Achieving power and agility in a small size robot

The UQ RoboRoos have been developed to participate in the RoboCup robot soccer small size league over several years. RoboCup 2001 saw a focus on the mechanical design of the RoboRoos, with the introduction of an omni-directional drive system and a high power kicker. The change in mechanical design had implications for the rest of the system particularly navigation and multi-robot planning. In addition, the overhead vision system was upgraded to improve reliability and robustness.

Designing a Computer Vision System for Underwater Robotic Interventions

This thesis deals with the challenging problem of designing systems able to perceive objects in underwater environments. In the last few decades research activities in robotics have advanced the state of art regarding intervention capabilities of autonomous systems. State of art in fields such as localization and navigation, real time perception and cognition, safe action and manipulation capabilities, applied to ground environments (both indoor and outdoor) has now reached such a readiness level that it allows high level autonomous operations. On the opposite side, the underwater environment remains a very difficult one for autonomous robots. Water influences the mechanical and electrical design of systems, interferes with sensors by limiting their capabilities, heavily impacts on data transmissions, and generally requires systems with low power consumption in order to enable reasonable mission duration. Interest in underwater applications is driven by needs of exploring and intervening in environments in which human capabilities are very limited. Nowadays, most underwater field operations are carried out by manned or remotely operated vehicles, deployed for explorations and limited intervention missions. Manned vehicles, directly on-board controlled, expose human operators to risks related to the stay in field of the mission, within a hostile environment. Remotely Operated Vehicles (ROV) currently represent the most advanced technology for underwater intervention services available on the market. These vehicles can be remotely operated for long time but they need support from an oceanographic vessel with multiple teams of highly specialized pilots. Vehicles equipped with multiple state-of-art sensors and capable to autonomously plan missions have been deployed in the last ten years and exploited as observers for underwater fauna, seabed, ship wrecks, and so on. On the other hand, underwater operations like object recovery and equipment maintenance are still challenging tasks to be conducted without human supervision since they require object perception and localization with much higher accuracy and robustness, to a degree seldom available in Autonomous Underwater Vehicles (AUV). This thesis reports the study, from design to deployment and evaluation, of a general purpose and configurable platform dedicated to stereo-vision perception in underwater environments. Several aspects related to the peculiar environment characteristics have been taken into account during all stages of system design and evaluation: depth of operation and light conditions, together with water turbidity and external weather, heavily impact on perception capabilities. The vision platform proposed in this work is a modular system comprising off-the-shelf components for both the imaging sensors and the computational unit, linked by a high performance ethernet network bus. The adopted design philosophy aims at achieving high flexibility in terms of feasible perception applications, that should not be as limited as in case of a special-purpose and dedicated hardware. Flexibility is required by the variability of underwater environments, with water conditions ranging from clear to turbid, light backscattering varying with daylight and depth, strong color distortion, and other environmental factors. Furthermore, the proposed modular design ensures an easier maintenance and update of the system over time. Performance of the proposed system, in terms of perception capabilities, has been evaluated in several underwater contexts taking advantage of the opportunity offered by the MARIS national project. Design issues like energy power consumption, heat dissipation and network capabilities have been evaluated in different scenarios. Finally, real-world experiments, conducted in multiple and variable underwater contexts, including open sea waters, have led to the collection of several datasets that have been publicly released to the scientific community. The vision system has been integrated in a state of the art AUV equipped with a robotic arm and gripper, and has been exploited in the robot control loop to successfully perform underwater grasping operations.

CASIMIRO: a robot head for human-computer interaction

The physical appearance and behavior of a robot is an important asset in terms of Human-Computer Interaction. Multimodality is also fundamental, as we humans usually expect to interact in a natural way with voice, gestures, etc. People approach complex interaction devices with stances similar to those used in their interaction with other people. In this paper we describe a robot head, currently under development, that aims to be a multimodal (vision, voice, gestures,...) perceptual user interface.

A C80 DSP-based active vision system for real-time tracking

[EN]Active Vision Systems can be considered as dynamical systems which close the loop around artificial visual perception, controlling camera parameters, motion and also controlling processing to simplify, accelerate and do more robust visual perception. Research and Development in Active Vision Systems [Aloi87], [Bajc88] is a main area of interest in Computer Vision, mainly by its potential application in different scenarios where real-time performance is needed such as robot navigation, surveillance, visual inspection, among many others. Several systems have been developed during last years using robotic-heads for this purpose...

Fast and accurate hand pose detection for human-robot interaction

[EN]Enabling natural human-robot interaction using computer vision based applications requires fast and accurate hand detection. However, previous works in this field assume different constraints, like a limitation in the number of detected gestures, because hands are highly complex objects difficult to locate. This paper presents an approach which integrates temporal coherence cues and hand detection based on wrists using a cascade classifier. With this approach, we introduce three main contributions: (1) a transparent initialization mechanism without user participation for segmenting hands independently of their gesture, (2) a larger number of detected gestures as well as a faster training phase than previous cascade classifier based methods and (3) near real-time performance for hand pose detection in video streams.

Improving the Accuracy of 3-D Reconstruction in Robotic Vision Applications

Thesis (Ph.D.)--University of Washington, 2016-08