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American Control Conference (ACC)

作者： D. J. Antunes W. P. M. H. Heemels J. P. Hespanha C. J. Silvestre Hybrid and Networked Systems Group Department of Mechanical Engineering Eindhovan University of Technology Netherlands Department of Electrical and Computer Engineering University of California Santa Barbara CA USA Institute for Systems and Robotics Instituto Superior Técnico Lisboa Portugal Faculty of Science and Technology University of Macau Taipa Macao China

ISBN: (纸本)9781457710957

We consider a networked control system where a plant is connected to a remote controller via a shared network that allows only one user to transmit at a given time. At each transmission time, the controller decides between sampling one of the plant's sensors or transmitting control data to the plant. We tackle the problem of simultaneously designing a policy for scheduling decisions and a policy for control inputs so as to optimize a quadratic objective. Using the framework of dynamic programming, we propose a rollout strategy by which the scheduling and control decisions are determined at each transmission time as the ones that lead to optimal performance over a given horizon assuming that from then on controller and sensors transmit in a periodic order and the control law is a standard optimal law for periodic systems. We show that this rollout strategy results in a protocol where scheduling decisions are based on the state estimate and error covariance matrix of a Kalman estimator, and must be determined on-line. We contrast the solution to this problem with the solution to the seemingly similar sensor scheduling problem where optimal scheduling decisions can be determined off-line. We highlight how the protocol obtained from the rollout algorithm can be implemented in a distributed way in broadcast networks. Moreover, it follows by construction of rollout algorithms that our proposed scheduling method can outperform any periodic scheduling of transmissions.

关键词： Sensors Protocols Scheduling Optimal scheduling Covariance matrix Processor scheduling Networked control systems

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Coral reef mosaicking using Teardrop and Fast Image Labeling

Coral reef mosaicking using Teardrop and Fast Image Labeling

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OCEANS - Europe

作者： Francis James Corpuz Prospero Naval Eusebio Capili Jaylord Jauod Roel John Judilla Maricor Soriano Vision and Image Processing Group Instrumentation Physics Laboratory National Institute of Physics Computer Vision and Machine Intelligence Group Department of Computer Science College of Engineering University of Philippines Quezon Philippines Computer Vision and Machine Intelligence Group Department of Computer Science College of Engineering University of Philippines Quezon Philippines Mapua Robotics Center Special Projects Laboratory Institutional Laboratory Mgmt Office Mapua Institute of Technology Manila Philippines Vision and Image Processing Group Instrumentation Physics Laboratory National Institute of Physics University of Philippines Quezon Philippines

In this paper, we present an inexpensive system for diverless video capture and fast image stitching of image frames for rapid reef assessment of shallow coral reefs. Our system has two main components: 1) Teardrop, a boat-towable, winged hull apparatus designed to house a commercial digital camera, and 2) a mosaicking algorithm to stitch the coral reef video into mosaics for further appreciation and analysis. The captured reef video is then separated into image frames which are to be stitched sequentially using Fast Image Labeling. The overlap between image frames is estimated using Single-Step DFT, an efficient sub-pixel estimation algorithm. The estimated overlap is used to compute for the area to be added to the mosaic space. The overlapping section between succeeding image-pairs are stitched along a seam determined by a minimal-cost path using dynamic programming. The visibility of the seam boundaries is further minimized by utilizing blending on multi-resolution splines. Experimental results on automated reef mosaics creation from actual coral reef video taken using Teardrop shows the performance of the system described. The main contribution of this work is the demonstration of a rapid reef visualization system using a diverless system and commercially available, non-research-grade imaging equipment.

关键词： Image segmentation Sea measurements Cameras Labeling Discrete Fourier transforms Sea floor

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Modeling and Identification of Serial Two-Link Manipulator Considering Joint Nonlinearities for Industrial Robots Control

Modeling and Identification of Serial Two-Link Manipulator C...

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IEEE/RSJ International Conference on Intelligent robotics and Systems

作者： Eui-Jin Kim Kenta Seki Makoto Iwasaki Sang-Hun Lee Department of Computer Science and Engineering Nagoya Institute of Technology Gokiso Showa Nagoya Japan and Robotics Research Department Engine & Machinery Research Institute Hyundai Heavy Industries Co. Ltd.. 102-18. Mabuk-dong. Giheung-gu Yong Department of Computer Science and Engineering Nagoya Institute of Technology Gokiso Showa Nagoya Japan Medical System Research Department. Corporate Technology Institute. Hyundai Heavy Industries Co.. Ltd..

ISBN: (纸本)9781467317375

This paper presents modeling and identification of a serial two-link manipulator considering joint nonlinearities for industrial robot control. In order to achieve the desired performance using model-based control approaches, it is important to obtain relevant models of both kinematics and dynamics including the nonlinear effects. The main nonlinear components which result in trajectory tracking errors of typical multi-axis industrial robot, are joint nonlinearities in each axis and dynamic coupling effects between different axes. A parametric modeling approach is presented to reproduce behaviors of a serial two-link manipulator with joint nonlinearities. Nonlinear stiffness, angular transmission errors, and friction in these two links are directly identified as joint nonlinearities. As a case study, this approach is applied for the serial two-link arm of a typical multi-axis industrial robot, which has low frequency vibration modes and significantly affect to the trajectory performance. Effectiveness of the modeling is verified by comparative studies with numerical simulations and experiments. Finally, a simple 2-degrees-of-freedom controller on the basis of the identified dynamic model has been applied to improve the performance of trajectory tracking and residual vibration suppression.

关键词： Identification Considering residual industrial robots nonlinearity Modeling trajectory tracking Serial Publications Joints Joints vibration suppression Axis MULTIAXIAL

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Overcoming Occlusions in Eye-in-Hand Visual Search

Overcoming Occlusions in Eye-in-Hand Visual Search

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American Control Conference

作者： Sina Radmard David Meger Elizabeth A. Croft James J. Little Collaborative Advanced Robotics and Intelligent Systems Laboratory Mechanical Engineering Department University of British Columbia V6T1Z4 Canada Laboratory for Computational Intelligence Department of Computer Science University of British Columbia V6T1Z4 Canada

ISBN: (纸本)9781457710957

In this paper we propose a method for handling persistent visual occlusions that disrupt visual tracking for eye-in-hand systems. This approach provides an efficient strategy for the robot to "look behind" the occlusion while respecting the robot's physical constraints. Specifically, we propose a decoupled search strategy combining a naive pan tilt search with a sensor placement approach, to reduce the strategy's computational cost. We proceed by mapping limited environmental data into the robot configuration space and then planning within a constrained region. We use a particle filter to continuously estimate the target location, while our configuration-based cost function plans a goal location for the camera frame, taking into account robot singularity, self-collision and joint limit constraints. To validate our algorithm, we implemented it on an eye-in-hand robot system. Experimental results for various situations support the feasibility of our approach for quickly recovering fully occluded moving targets. Finally we discuss the implications of this approach to mobile robot platforms.

关键词： Joints Cameras Robot vision systems Target tracking Planning

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Function Substitution: Towards Constraint Solving in Software Testing

Function Substitution: Towards Constraint Solving in Softwar...

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International Conference on Quality Software

作者： Xin Feng Simon Marr Tony O'Callaghan Zhi Quan Zhou Jacques Carette Division of Science and Technology BNU-HKBU United International College Zhuhai China Marine Robotics Research Centre University of Limerick Limerick Ireland Interaction Design Centre University of Limerick Limerick Ireland School of Computer Science and Software Engineering University of Wollongong Wollongong Australia Department of Computing and Software McMaster University Hamilton Canada

Constraint solving is a fundamental tenet of most test case generation strategies. However, conventional constraint solving methods were not designed in consideration of that aspect of test case generation. It has led to a situation where test case generation techniques can miss test cases when constraints contain function invocations. This is due to the fact that, when solving constraints to generate test cases, function invocations are not effectively handled and, as a result, solutions to some constraints are not found even though they do exist. This problem occurs in both specification-based and code-based testing. To address the problem, this paper presents a function substitution method that transforms test case constraints that contain certain types of functions into equivalent constraints that do not contain those functions. The transformation preserves the solution space and avoids missed test cases. As a result, the completeness of test case generation can be improved.

关键词： Educational institutions Input variables Marketing and sales Software Frequency modulation Software testing

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Robots for Humanity: User-Centered Design for Assistive Mobile Manipulation

Robots for Humanity: User-Centered Design for Assistive Mobi...

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IEEE/RSJ International Conference on Intelligent robotics and Systems

作者： Tiffany L. Chen Matei Ciocarlie Steve Cousins Phillip Grice Kelsey Hawkins Kaijen Hsiao Charles C. Kemp Chih-Hung King Daniel A. Lazewatsky Adam Leeper Hai Nguyen Andreas Paepcke Caroline Pantofaru William D. Smart Leila Takayama Healthcare Robotics Lab Georgia Institute of Technology Atlanta GA USA. Willow Garage Inc. Menlo Park CA USA. Media and Machines Laboratory Department of Computer Science and Engineering Washington University in St. Louis St. Louis MO USA.

ISBN: (纸本)9781467317375

The Robots for Humanity project aims to enable people with severe motor impairments to interact with their own bodies and their environment through the use of an assistive mobile manipulator, thereby improving their quality of life. Assistive mobile manipulators (AMMs) are mobile robots that physically manipulate the world in order to provide assistance to people with disabilities. They present an exciting frontier for assistive technology, as they can operate away from the user, have a large dexterous workspace (due to their mobility), and not directly encumber their users. The cornerstone of this project is an ongoing, interactive design process with a quadriplegic user, Henry Evans, and his wife and primary caregiver, Jane Evans. Henry has been enabled, through the use of a PR2 robot, to scratch his own face, shave, fetch a towel from his kitchen, and hand out Halloween candy to trick-or-treating children at a local mall.

关键词： AMM PR2 primary

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Erratum to “A New Solution for Camera Calibration and Real-Time Image Distortion Correction in Medical Endoscopy–Initial Technical Evaluation” [Mar 12 634-644]

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IEEE Transactions on Biomedical engineering 2012年第7期59卷 2095-2095页

作者： Rui Melo João P. Barreto Gabriel Falcão Institute for Systems and Robotics and Department of Electrical and Computer Engineering Faculty of Science and Technology Coimbra Portugal Instituto de Telecomunicações Faculty of Science and Technology Coimbra Portugal

In the above-titled paper (ibid., vol. 59, no. 3, pp. 634-644, Mar. 2012), the affiliation of G. Falcao should have read as follows: G. Falcao is with the Instituto de Telecomunicacoes and department of Electrical and computer engineering, Faculty of science and Technology, University of Coimbra, 3030-290 Coimbra, Portugal (e-mail: gff@***).

关键词： Cameras Calibration Biomedical imaging Endoscopes Graphics processing unt Lenses

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A mechanism to recover voice from logged VoIP sessions based on RTP

A mechanism to recover voice from logged VoIP sessions based...

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2011 IEEE 5th International Conference on Internet Multimedia Systems Architecture and Application, IMSAA 2011

作者： Choudhury, Paromita Kumar, K. R. Prasanna Athithan, G. Nandi, Sukumar Center for Artificial Intelligence and Robotics Bangalore Karnataka - 560093 India Department of Computer Science and Engineering Indian Institute of Technology Guwahati - 781039 India

ISBN: (纸本)9781457713286

The convergence of voice and data on Internet Protocol (IP) networks has led to tremendous growth of Voice over IP (VoIP). While SIP/ H.323 are dominant signaling protocols, RTP is widely used for media transfer. Certain situations may require logging of RTP sessions along with the signaling information for call and voice analysis. Recovering voice from RTP packets requires explicit handling of RTP stack and decoding. In this paper, we propose a scheme that uses softphones with appropriate codec support for voice recovery from logged RTP packets. It is done using inherent provisions of RTP, specifically SSRC-multiplexing. The scheme also suggests the possibility of an active stream injection attack in RTP based VoIP. © 2011 IEEE.

关键词： Voice/data communication systems

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Accurate Evaluation of a Distance Function for Optimization-based Motion Planning

Accurate Evaluation of a Distance Function for Optimization-...

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IEEE/RSJ International Conference on Intelligent robotics and Systems

作者： Youngeun Lee Sébastien Lengagne Abderrahmane Kheddar Young J. Kim Department of Computer Science and Engineering at Ewha Womans University in Seoul Korea Karlsruhe Institute of Technology Institute for Anthropomatics Humanoids and Intelligence Systems Lab Adenauerring 2 76131 Karlsruhe Germany CNRS-AIST Joint Robotics Laboratory (JRL) UMI3218/CRT Tsukuba Japan and also with the CNRS-UM2 LIRMM Interactive Digital Human group Montpellier France.

ISBN: (纸本)9781467317375

We propose three novel methods to evaluate a distance function for robotic motion planning based on semi-infinite programming (SIP) framework;these methods include golden section search (GSS), conservative advancement (CA) and a hybrid of GSS and CA. The distance function can have a positive and a negative value, each of which corresponds to the Euclidean distance and penetration depth, respectively. In our approach, each robot's link is approximated and bounded by a capsule shape, and the distance between some selected link pairs is continuously evaluated along the joint's trajectory, provided by the SIP solver, and the global minimum distance is found. This distance is fed into the SIP solver, which subsequently suggests a new trajectory. This process is iterated until no negative distance is found anywhere in the links of the robot. We have implemented the three distance evaluation methods, and experimentally validated that the proposed methods effectively and accurately find the global minimum distances to generate a self-collision-free motion for the HRP-2 humanoid robot. Moreover, we demonstrate that the hybrid method outperforms other two methods in terms of computational speed and reliability.

关键词： Motion Planning GSS SIP motion planning distance function Aerospace ground services PRNP gene STATE IMPLEMENTATION PLANS TSACC gene Global Minimum Robot Euclidean distance

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TPS-SURF-SAC matching approach of feature point applied to deformation measurement of nonrigid tissues from MR images

TPS-SURF-SAC matching approach of feature point applied to d...

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2011 IEEE International Conference on robotics and Biomimetics, ROBIO 2011

作者： Zhang, Xubing Hirai, Shinichi Department of Robotics Faculty of Science and Engineering Ritsumeikan University Kusatsu Shiga 525-8577 Japan School of Computer Science Wuhan Textile University Wuhan 430073 China

ISBN: (纸本)9781457721373

Due to the nonlinear deformation of the nonrigid and nonuniform biological tissues, it is difficult whereas important to correctly match a number of feature points distributed somewhat uniform in the tissues from MR images for deformation measurement. In this paper, the authors present TPS-SURF-SAC matching method and mismatching elimination method based on TPS clustering. Firstly the matching region is identified by a TPS for every query point. Then the SURF descriptors and the proposed Spatial Association Correspondence (SAC) method are combined to match the feature points. Finally, using clustering the coordinate differences between the matching points obtained using TPS-SURF-SAC method and the matching points matched by TPS model, most of wrong match points are eliminated. After every iterative processing of matching and mismatching elimination, the updated TPS model becomes more accurate and more correctly matched points can be identified than that of the previous iteration. The experimental results showed that the proposed method outperformed the single SURF and SIFT methods. © 2011 IEEE.

关键词： Tissue

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