206 research outputs found

    An Overview of Advances of Pattern Recognition Systems in Computer Vision

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    26 pagesFirst of all, let's give a tentative answer to the following question: what is pattern recognition (PR)? Among all the possible existing answers, that which we consider being the best adapted to the situation and to the concern of this chapter is: "pattern recognition is the scientific discipline of machine learning (or artificial intelligence) that aims at classifying data (patterns) into a number of categories or classes". But what is a pattern? A pattern recognition system (PRS) is an automatic system that aims at classifying the input pattern into a specific class. It proceeds into two successive tasks: (1) the analysis (or description) that extracts the characteristics from the pattern being studied and (2) the classification (or recognition) that enables us to recognise an object (or a pattern) by using some characteristics derived from the first task

    Efficient and secure real-time mobile robots cooperation using visual servoing

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    This paper deals with the challenging problem of navigation in formation of mobiles robots fleet. For that purpose, a secure approach is used based on visual servoing to control velocities (linear and angular) of the multiple robots. To construct our system, we develop the interaction matrix which combines the moments in the image with robots velocities and we estimate the depth between each robot and the targeted object. This is done without any communication between the robots which eliminate the problem of the influence of each robot errors on the whole. For a successful visual servoing, we propose a powerful mechanism to execute safely the robots navigation, exploiting a robot accident reporting system using raspberry Pi3. In addition, in case of problem, a robot accident detection reporting system testbed is used to send an accident notification, in the form of a specifical message. Experimental results are presented using nonholonomic mobiles robots with on-board real time cameras, to show the effectiveness of the proposed method

    Image-Guided Robot-Assisted Techniques with Applications in Minimally Invasive Therapy and Cell Biology

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    There are several situations where tasks can be performed better robotically rather than manually. Among these are situations (a) where high accuracy and robustness are required, (b) where difficult or hazardous working conditions exist, and (c) where very large or very small motions or forces are involved. Recent advances in technology have resulted in smaller size robots with higher accuracy and reliability. As a result, robotics is fi nding more and more applications in Biomedical Engineering. Medical Robotics and Cell Micro-Manipulation are two of these applications involving interaction with delicate living organs at very di fferent scales.Availability of a wide range of imaging modalities from ultrasound and X-ray fluoroscopy to high magni cation optical microscopes, makes it possible to use imaging as a powerful means to guide and control robot manipulators. This thesis includes three parts focusing on three applications of Image-Guided Robotics in biomedical engineering, including: Vascular Catheterization: a robotic system was developed to insert a catheter through the vasculature and guide it to a desired point via visual servoing. The system provides shared control with the operator to perform a task semi-automatically or through master-slave control. The system provides control of a catheter tip with high accuracy while reducing X-ray exposure to the clinicians and providing a more ergonomic situation for the cardiologists. Cardiac Catheterization: a master-slave robotic system was developed to perform accurate control of a steerable catheter to touch and ablate faulty regions on the inner walls of a beating heart in order to treat arrhythmia. The system facilitates touching and making contact with a target point in a beating heart chamber through master-slave control with coordinated visual feedback. Live Neuron Micro-Manipulation: a microscope image-guided robotic system was developed to provide shared control over multiple micro-manipulators to touch cell membranes in order to perform patch clamp electrophysiology. Image-guided robot-assisted techniques with master-slave control were implemented for each case to provide shared control between a human operator and a robot. The results show increased accuracy and reduced operation time in all three cases

    2-D Ultrasound Probe Complete Guidance by Visual Servoing Using Image Moments

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    Model-Free 3D Shape Control of Deformable Objects Using Novel Features Based on Modal Analysis

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    Shape control of deformable objects is a challenging and important robotic problem. This paper proposes a model-free controller using novel 3D global deformation features based on modal analysis. Unlike most existing controllers using geometric features, our controller employs a physically-based deformation feature by decoupling 3D global deformation into low-frequency mode shapes. Although modal analysis is widely adopted in computer vision and simulation, it has not been used in robotic deformation control. We develop a new model-free framework for modal-based deformation control under robot manipulation. Physical interpretation of mode shapes enables us to formulate an analytical deformation Jacobian matrix mapping the robot manipulation onto changes of the modal features. In the Jacobian matrix, unknown geometry and physical properties of the object are treated as low-dimensional modal parameters which can be used to linearly parameterize the closed-loop system. Thus, an adaptive controller with proven stability can be designed to deform the object while online estimating the modal parameters. Simulations and experiments are conducted using linear, planar, and solid objects under different settings. The results not only confirm the superior performance of our controller but also demonstrate its advantages over the baseline method.Comment: Accepted by the IEEE Transactions on Robotics. The paper will appear in the IEEE Transactions on Robotics. IEEE copyrigh

    Aerial robotics in building inspection and maintenance

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    Buildings need periodic revision about their state, materials degrade with time and repairs or renewals have to be made driven by maintenance needs or safety requirements. That happens with any kind of buildings and constructions: housing, architecture masterpieces, old and ancient buildings and industrial buildings. Currently, nearly all of these tasks are carried out by human intervention. In order to carry out the inspection or maintenance, humans need to access to roofs, façades or other areas hard to reach and otherwise potentially hazardous location to perform the task. In some cases, it might not be feasible to access for inspection. For instance, in industry buildings operation must be often interrupted to allow for safe execution of such tasks; these shutdowns not only lead to substantial production loss, but the shutdown and start-up operation itself causes risks to human and environment. In touristic buildings, access has to be restricted with the consequent losses and inconveniences to visitors. The use of aerial robots can help to perform this kind of hazardous operations in an autonomous way, not only teleoperated. Robots are able to carry sensors to detect failures of many types and to locate them in a previously generated map, which the robot uses to navigate. Some of those sensors are cameras in different spectra (visual, near-infrared, UV), laser, LIDAR, ultrasounds and inertial sensory system. If the sensory part is crucial to inspect hazardous areas in buildings, the actuation is also important: the aerial robot can carry small robots (mainly crawler) to be deployed to perform more in-depth operation where the contact between the sensors and the material is basic (any kind of metallic part: pipes, roofs, panels…). The aerial robot has the ability to recover the deployed small crawler to be reused again. In this paper, authors will explain the research that they are conducting in this area and propose future research areas and applications with aerial, ground, submarine and other autonomous robots within the construction field.Peer ReviewedPostprint (author's final draft

    Theoretical improvements in the stability analysis of a new class of model-free visual servoing methods

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