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SIMO detection schemes for underwater optical wireless communication under turbulence

Photonics Research 2015年第3期3卷 48-53页

作者： Weihao Liu Zhengyuan Xu Liuqing Yang School of Information Science and Technology University of Science and Technology of ChinaHefeiChina State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyangChina Key Laboratory of Wireless-Optical Communications Chinese Academy of SciencesHefeiChina Department of Electrical and Computer Engineering Colorado State UniversityFort CollinsColorado 80521USA

In underwater optical wireless communication(UOWC),a channel is characterized by abundant scattering/absorption effects and optical *** previous studies on UOWC have been limited to scattering/absorption ***,experiments in the literature indicate that underwater optical turbulence(UOT)can cause severe degradation of UOWC *** this paper,we characterize an UOWC channel with both scattering/absorption and UOT taken into consideration,and a spatial diversity receiver scheme,say a singleinput–multiple-output(SIMO) scheme,based on a light-emitting-diode(LED) source and multiple detectors is proposed to mitigate deep *** Monte Carlo based statistical simulation method is introduced to evaluate the bit-error-rate performance of the *** is shown that spatial diversity can effectively reduce channel fading and remarkably extend communication range.

关键词： SIMO detection schemes for underwater optical wireless communication under turbulence than

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Tightly-coupled monocular visual-inertial fusion for autonomous flight of rotorcraft MAVs

Tightly-coupled monocular visual-inertial fusion for autonom...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Shaojie Shen Nathan Michael Vijay Kumar Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Hong Kong China Robotics Institute Carnegie Mellon University Pittsburgh PA USA GRASP Laboratory University of Pennsylvania Philadelphia PA USA

There have been increasing interests in the robotics community in building smaller and more agile autonomous micro aerial vehicles (MAVs). In particular, the monocular visual-inertial system (VINS) that consists of only a camera and an inertial measurement unit (IMU) forms a great minimum sensor suite due to its superior size, weight, and power (SWaP) characteristics. In this paper, we present a tightly-coupled nonlinear optimization-based monocular VINS estimator for autonomous rotorcraft MAVs. Our estimator allows the MAV to execute trajectories at 2 m/s with roll and pitch angles up to 30 degrees. We present extensive statistical analysis to verify the performance of our approach in different environments with varying flight speeds.

关键词： Cameras Optimization Robot sensing systems Vehicles Quaternions Measurement uncertainty Mathematical model

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Microscopic image segmentation using quantum inspired evolutionary algorithm

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Journal of Advanced Microscopy Research 2015年第3期10卷 164-173页

作者： Choudhury, Alokeparna Samanta, Sourav Dey, Nilanjan Ashour, Amira S. Balas-Timar, Dana Gospodinov, Mitko Gospodinova, Evgeniya Department of Computer Science and Engineering University Institute of Technology Burdwan West Bengal713104 India Department of Information Technology Techno India College of Technology Kolkata700156 India Department of Electronics and Electrical Communications Engineering Faculty of Engineering Tanta University 31527 Egypt Aurel Vlaicu University of Arad Arad310130 Romania Institute of Systems Engineering and Robotics Bulgarian Academy of Sciences Sofia1113 Bulgaria

Image segmentation has became an important research area for various medical imaging fields. The automated complex analytical process makes it a huge time consuming procedure. The intention to microscopic images segmentation is to extract the cellular, nuclear or tissue components. This is considered a challenging process due to the large variations of features of these components (size, shape, orientation or texture). In this paper, a novel approach to deal with rats' microscopic hippocampus images segmentation based on the hybrid evolutionary strategy (ES) is proposed. The proposed work used the quantum-inspired evolutionary algorithm (QIEA) to establish the optimal level for the multilevel thresholding. The QIEA depends on both quantum and evolutionary computing. An intensive works for automatic hippocampus segmentation is performed on a database of 179 images. The acquired results have demonstrated that the proposed algorithm provides superior segmentation with eight levels (L = 8), that offer the highest correlation between the original and the corresponding segmented image. © Copyright 2015 American Scientific Publishers All rights reserved.

关键词： Evolutionary algorithms

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Fiber optically sensorized multi-fingered robotic hand

Fiber optically sensorized multi-fingered robotic hand

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： L. Jiang K. Low J. Costa R. J. Black Yong-Lae Park Department of Mechanical Engineering Carnegie Mellon University Pittsburgh PA USA Intelligent Fiber Optic Systems (IFOS) Corp. Santa Clara CA USA Robotics Institute in the School of Computer Science and the Department of Mechanical Engineering Carnegie Mellon University Pittsburgh PA USA

We present the design, fabrication, and characterization of a fiber optically sensorized robotic hand for multi purpose manipulation tasks. The robotic hand has three fingers that enable both pinch and power grips. The main bone structure was made of a rigid plastic material and covered by soft skin. Both bone and skin contain embedded fiber optics for force and tactile sensing, respectively. Eight fiber optic strain sensors were used for rigid bone force sensing, and six fiber optic strain sensors were used for soft skin tactile sensing. For characterization, different loads were applied in two orthogonal axes at the fingertip and the sensor signals were measured from the bone structure. The skin was also characterized by applying a light load on different places for contact localization. The actuation of the hand was achieved by a tendon-driven under-actuated system. Gripping motions are implemented using an active tendon located on the volar side of each finger and connected to a motor. Opening motions of the hand were enabled by passive elastic tendons located on the dorsal side of each finger.

关键词： Robot sensing systems Tendons Bones Skin Optical fiber sensors

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Compensation for torque fluctuation caused by temperature change in fast and precise positioning of galvanometer scanners

Compensation for torque fluctuation caused by temperature ch...

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International Conference on Mechatronics (ICM)

作者： Daisuke Matsuka Satoshi Fukushima Makoto Iwasaki Robotics Research Department Hitachi Research Laboratory Hitachi Ltd. Hitachinaka Ibaraki JAPAN Designing Department Via Mechanics Ltd. Kanagawa JAPAN Dept. of Computer Science & Engineering Nagoya Institute of Technology Aichi JAPAN

This paper presents a compensation approach for torque fluctuation caused by temperature change of galvanometer scanners in laser-positioning servomechanisms. The galvanometer scanner is driven by a swaying motor which is used in laser drilling machines because of its precise positioning ability. However, since the motor temperature rises during the high speed motion, the reversible flux loss occurs. As a result, thermal demagnetization decreases a torque constant and the overshoot occurs at the settling waveform, resulting in deterioration of precision positioning performance. The proposed approach can estimate the temperature of a permanent magnet with a high degree of accuracy by detected current value using a pre-identified cooling coefficient. Specifically, the approach considers a rise in heat caused by eddy current loss. Then the approach compensates for torque fluctuation using the estimated temperature of the permanent magnet. The proposed approach has been verified by experiments using galvanometer scanners.

关键词： Coils Torque Eddy currents Heating Temperature measurement Stators Permanent magnets

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Easy-to-use, General, and Accurate Multi-Kinect Calibration and its Application to Gait Monitoring for Fall Prediction

Easy-to-use, General, and Accurate Multi-Kinect Calibration ...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： Aaron N. Staranowicz Christopher Ray Gian-Luca Mariottini the ASTRA Robotics Lab at the Department of Computer Science and Engineering University of Texas at Arlington 500 UTA Boulevard Arlington TX 76019 USA the Department of Kinesiology University of Texas at Arlington 500 West Nedderman Drive Arlington TX 76019 USA

ISBN: (纸本)9781424492695

Falls are the most-common causes of unintentional injury and death in older adults. Many clinics, hospitals, and health-care providers are urgently seeking accurate, low-cost, and easy-to-use technology to predict falls before they happen, e.g., by monitoring the human walking pattern (or "gait"). Despite the wide popularity of Microsoft's Kinect and the plethora of solutions for gait monitoring, no strategy has been proposed to date to allow non-expert users to calibrate the cameras, which is essential to accurately fuse the body motion observed by each camera in a single frame of reference. In this paper, we present a novel multi-Kinect calibration algorithm that has advanced features when compared to existing methods: 1) is easy to use, 2) it can be used in any generic Kinect arrangement, and 3) it provides accurate calibration. Extensive real-world experiments have been conducted to validate our algorithm and to compare its performance against other multi-Kinect calibration approaches, especially to show the improved estimate of gait parameters. Finally, a MATLAB Toolbox has been made publicly available for the entire research community.

关键词： Easy-to-use General Fall Prediction

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Learning by observation for surgical subtasks: Multilateral cutting of 3D viscoelastic and 2D Orthotropic Tissue Phantoms

Learning by observation for surgical subtasks: Multilateral ...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Adithyavairavan Murali Siddarth Sen Ben Kehoe Animesh Garg Seth McFarland Sachin Patil W. Douglas Boyd Susan Lim Pieter Abbeel Ken Goldberg Department of Electrical Engineering and Computer Science (EECS) Center for Automation and Learning for Medical Robotics (Cal-MR) University of California Berkeley Berkeley CA USA Mechanical Engineering Ohio University Department of Electrical Engineering and Computer Science Athens OH US Division of Cardiothoracic Surgery University of California Davis Medical Center Sacramento CA USA Centre for Breast Screening and Surgery Centre for Robotic Surgery Singapore IEOR and EECS

Automating repetitive surgical subtasks such as suturing, cutting and debridement can reduce surgeon fatigue and procedure times and facilitate supervised tele-surgery. Programming is difficult because human tissue is deformable and highly specular. Using the da Vinci Research Kit (DVRK) robotic surgical assistant, we explore a “Learning By Observation” (LBO) approach where we identify, segment, and parameterize motion sequences and sensor conditions to build a finite state machine (FSM) for each subtask. The robot then executes the FSM repeatedly to tune parameters and if necessary update the FSM structure. We evaluate the approach on two surgical subtasks: debridement of 3D Viscoelastic Tissue Phantoms (3d-DVTP), in which small target fragments are removed from a 3D viscoelastic tissue phantom; and Pattern Cutting of 2D Orthotropic Tissue Phantoms (2d-PCOTP), a step in the standard Fundamentals of Laparoscopic Surgery training suite, in which a specified circular area must be cut from a sheet of orthotropic tissue phantom. We describe the approach and physical experiments with repeatability of 96% for 50 trials of the 3d-DVTP subtask and 70% for 20 trials of the 2d-PCOTP subtask. A video is available at: http://***/Robot-Surgery-Video-Oct-2014.

关键词： Phantoms Three-dimensional displays Surgery Motion segmentation Grippers Robot sensing systems

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Design, fabrication and dynamic modeling of a new step-walker robot platform using Wi-Fi based controller

Design, fabrication and dynamic modeling of a new step-walke...

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IEEE International Symposium on Innovations in Intelligent Systems and Applications (INISTA)

作者： Salar Basiri Armin Kasemi Langroodi Pooyan Piredeir Aryo Jamshidpey Mechatronics and Robotics Group Marlik Institute of Innovation and Technology Rasht Iran Department of Mechanical Engineering K. N. Toosi University of Technology Tehran Iran Department of Mechanical Engineering University of Guilan Rasht Iran Department of Computer Science & IT Institute for Advanced Studies in Basic Sciences Zanjan Iran

In this article, a step-walker robot is introduced. In recent years too many explorer and moving robots are designed and manufactured. These kinds of robots need a mechanism for climbing stairs or steps to explore and discover all sections of a building. This introduced mechanism is an optimum mechanism in terms of energy consumption while climbing a step or stair with a specific altitude. The robot which is introduced in this article contains two axes. Each axis can change its Vertical position independently. This position changes upon the stair or step's height. When the robot meets a step or stair, it can climb by changing its wheel's axes alternatively. This robot's cinematic and 3D modeling that will be used for choosing the proper DC motors and other essentials for making robot, is done by MATLAB and CATIA software solution package.

关键词： Robot sensing systems Robot kinematics Legged locomotion Mathematical model Wheels

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Towards an immersive and natural gesture controlled interface for intervention underwater robots

Towards an immersive and natural gesture controlled interfac...

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OCEANS - Europe

作者： Juan C. García Bruno Patrão Javier Pérez João Seabra Paulo Menezes Jorge Dias Pedro J. Sanz Universitat Jaume I Castello de la Plana Comunitat Valenciana ES Institute of Systems and Robotics University of Coimbra Coimbra Portugal Department of Computer Science and Engineering Universitat Jaume I Spain Khalifa University of Science and Technology and Research Abu UAE Dhabi

During underwater intervention missions, one of the critical issues, from the human-machine interaction perspective, concerns the operator's stress, which should be able to control the intervention system, mainly due to the high complexity of information displayed through specifically designed Graphical User Interface, and the usually available master-slave control architecture. So, this paper introduces a new approach with the aim to minimize the aforementioned drawbacks and, in the meantime, increasing the user's immersive feeling. Preliminary results are discussed highlighting the pros and cons of this novel procedure.

关键词： Cameras Robot vision systems Graphical user interfaces Proposals

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Confidence Preserving Machine for Facial Action Unit Detection

Confidence Preserving Machine for Facial Action Unit Detecti...

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International Conference on computer Vision (ICCV)

作者： Jiabei Zeng Wen-Sheng Chu Fernando De la Torre Jeffrey F. Cohn Zhang Xiong School of Computer Science and Engineering Beihang University Beijing China Robotics Institute Carnegie Mellon University Pittsburgh PA USA Carnegie Mellon University Pittsburgh PA US Department of Psychology University of Pittsburgh Pittsburgh PA USA

ISBN: (纸本)9781467383929

Varied sources of error contribute to the challenge of facial action unit detection. Previous approaches address specific and known sources. However, many sources are unknown. To address the ubiquity of error, we propose a Confident Preserving Machine (CPM) that follows an easy-to-hard classification strategy. During training, CPM learns two confident classifiers. A confident positive classifier separates easily identified positive samples from all else, a confident negative classifier does same for negative samples. During testing, CPM then learns a person-specific classifier using "virtual labels" provided by confident classifiers. This step is achieved using a quasi-semi-supervised (QSS) approach. Hard samples are typically close to the decision boundary, and the QSS approach disambiguates them using spatio-temporal constraints. To evaluate CPM, we compared it with a baseline single-margin classifier and state-of-the-art semi-supervised learning, transfer learning, and boosting methods in three datasets of spontaneous facial behavior. With few exceptions, CPM outperformed baseline and state-of-the art methods.

关键词： Training Gold Support vector machines Magnetic heads Manifolds Testing Boosting

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