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63rd Annual Meeting of the Institute of Navigation 2007

作者： Miller, Mikel Nguyen, Thao Yang, Chun Blasch, Erik Air Force Research Lab. MNG Air Force Research Lab. SNRN Sigtem Technology Inc. Air Force Research Lab. SNAA Department of Electrical and Computer Engineering Miami University of Ohio Advanced Guidance Division Munitions Directorate Air Force Research Laboratory Eglin AFB FL Department of EE AFIT Miami University of Ohio ION RTN IEEE AIAA Assessment and Integration Branch Sensors Directorate Air Force Research Laboratory WPAFB OH AFIT SPIE Wright-Patterson AFB OH Reference Systems Branch Sensors Directorate Air Force Research Laboratory WPAFB OH

ISBN: (纸本)1604232862

Three integration schemes, namely, coherent, noncoherent, and semi-coherent integration, and their variants are described in this paper for signal detection and tracking in such applications as pulsed Doppler radar and GPS receiver. We adopt a unified approach to present such integration schemes as best approximations to the likelihood ratio test (LRT) when the signal models are partially known to different extents. Formulas for the conditional probability density functions (pdfs) of the sufficient statistic under alternative hypotheses as well as the probability of detection (Pd) and probability of false alarm (Pfa) are given. Integration improvement factors and integration losses are then formulated. Connections of the semi-coherent integration scheme to the cyclic autocorrelation function, the discrete-time Wigner-Ville transform, and the radar ambiguity function are also outlined. Although most of the results are available in the literature, they are scattered in different textbooks and research papers. By presenting them in a cohesive and concise manner, the paper can serve as (1) an introductory material with key references for those who would like to study the subject further, (2) a quick reference for those who would like to compare these integration schemes, and (3) an integrated approach under varying conditions. Simulation results are presented to compare these integration schemes in terms of detection performance (P d and Pfa) as a function of signal to noise ratio (SNR) and integration interval under two operating conditions. One is for a signal with constant Doppler frequency and the other is for a linear frequency modulation signal (i.e., a chirp signal). We show the curves of the input SNR required under different chirp rates so as to maintain the same detection performance, the resulting LRTs for the different approaches, as well as simulated comparisons between trade-offs of Pd versus SNR.

关键词： Signal receivers

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F&A compensating variable bang-bang control algorithm for pneumatic driving glass-wall cleaning robot

F&A compensating variable bang-bang control algorithm for pn...

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2007 IEEE/RSJ International Conference on Intelligent Robots and systems

作者： W. Wang H. X. Zhang W. P. Yu G. H. Zong J. W. Zhang Robotics Institute School of Mechanical Engineering and Automation Beijing Aeronautics and Astronautics University Beijing China Institute of Technical Aspects of Multimodal Systems Department of Computer Science University of Hamburg Hamburg Germany Cognitive Technology Laboratory Shenzhen Institute of Advanced Technology Shenzhen China

To overcome the overshoot and oscillation in the normal Bang-Bang controller applied in the pneumatic driving glass-wall cleaning robot, this paper presents a F&A compensating variable Bang-Bang control algorithm for the pneumatic position servo. Besides a new cylinder driving plan is designed, the control algorithm is also improved by adding a fiction force compensating item in the chamber force evaluation equation. To adjust the controlling parameters dynamically, certain increasing functions, such as step function, linear function and arc-tangent function, are used to define the piston's expectative acceleration along with the reduction of the piston's position error. To testify the feasibility of the control algorithms with the above three expectative acceleration setting functions respectively, a pneumatic glass-wall cleaning robot "Sky Cleaner 4" is used as a testing platform to implement a series of on-load position servo experiments. And the different results of them are compared.

关键词： Bang-bang control Cleaning Robots Servomechanisms Testing Algorithm design and analysis Force control Equations Acceleration Error correction

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TRACKING CONTROL IN THE PRESENCE OF NONLINEAR DYNAMIC FRICTIONAL EFFECTS: ROBOT EXTENSION

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Asian Journal of Control 2008年第3期1卷

作者： M. Feemster D.M. Dawson A. Behal W. Dixon Matthew Feemster received the B.S degree in Electrical Engineering from Clemson University Clemson South Carolina in December 1994. Upon graduation he remained at Clemson University and received the M.S. degree in Electrical Engineering in 1997. During this time he also served as a research/teaching assistant. His research work focused on the design and implementation of various nonlinear control algorithms with emphasis on the induction motor and mechanical systems with friction present. He is currently working toward his Ph.D. degree in Electrical Engineering at Clemson University. Darren M. Dawson was born in 1962 in Macon Georgia. He received an Associate Degree in Mathematics from Macon Junior College in 1982 and a B.S. Degree in Electrical Engineering from the Georgia Institute of Technology in 1984. He then worked for Westinghouse as a control engineer from 1985 to 1987. In 1987 he returned to the Georgia Institute of Technology where he received the Ph.D. Degree in Electrical Engineering in March 1990. During this time he also served as a research/teaching assistant. In July 1990 he joined the Electrical and Computer Engineering Department and the Center for Advanced Manufacturing (CAM) at Clemson University where he currently holds the position of Professor. Under the CAM director's supervision he currently leads the Robotics and Manufacturing Automation Laboratory which is jointly operated by the Electrical and Mechanical Engineering departments. His main research interests are in the fields of nonlinear based robust adaptive and learning control with application to electro-mechanical systems including robot manipulators motor drives magnetic bearings flexible cables flexible beams and high-speed transport systems. Aman Behal was born in India in 1973. He received his Masters Degree in Electrical Engineering from Indian Institute of Technology Bombay in 1996. He is currently working towards a Ph.D in Controls and Robotics at Clemson University. His research focuses on the control of no

In this paper, we extend the observer/control strategies previously published in [25] to an n -link, serially connected, direct drive, rigid link, revolute robot operating in the presence of nonlinear friction effects modeled by the Lu-Gre model. In addition, we also present a new adaptive control technique for compensating for the nonlinear parameterizable Stribeck effects. Specifically, an adaptive observer/controller scheme is developed which contains a feedforward approximation of the Stribeck effects. This feedforward approximation is used in a composite controller/observer strategy which forces the average square integral of the position tracking error to an arbitrarily small value. Experimental results are included to illustrate the performance of the proposed controllers.

关键词： Friction compensation nonlinear control

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Runtime reconfiguration of a modular mobile robot with serial and parallel mechanisms

Runtime reconfiguration of a modular mobile robot with seria...

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2007 IEEE/RSJ International Conference on Intelligent Robots and systems

作者： H. X. Zhang S.Y. Chen W. Wang J. W. Zhang G. H. Zong Institute of Technical Aspects of Multimodal Systems Department of Computer Science University of Hamburg Hamburg Germany Dept of Informatics University of Hamburg Germany College of Information Engineering Zhejiang University of Technology Hangzhou China Robotic Institute School of Mechanical Engineering and Automation Beijing Aeronautics and Astronautics University Beijing China Cognitive Technology Laboratory Shenzhen Institute of Advanced Technology Shenzhen China

This paper presents a novel field robot JL-I based on a reconfigurable concept for urban search and rescue applications. The robot consists of three identical modules; each module is an entire robotic system that can perform distributed activities. It features three-degrees-of-freedom (DOF) active joints actuated by serial and parallel mechanisms for changing shape and flexible docking mechanism. The docking mechanism enables adjacent modules to connect or disconnect flexibly and automatically. DOF analysis, working space analysis and the kinematics of the 3D active joint between connected modules are studied thoroughly. In the end a series of successful tests confirm the principles and the robot's capabilities.

关键词： Runtime Mobile robots Orbital robotics Robotics and automation Space technology Intelligent robots Kinematics Testing Prototypes Accidents

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Distributed amplifiers with non-uniform filtering structures

Distributed amplifiers with non-uniform filtering structures

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2006 IEEE Radio Frequency Integrated Circuits Symposium

作者： Yunliang, Zhu Hui, Wu Laboratory for Advanced Integrated Circuits and Systems Department of Electrical and Computer Engineering University of Rochester Rochester NY

ISBN: (纸本)0780395727

This paper presents a new design concept to better control both passband and stop-band characteristics of distributed amplifiers (DAs) by using non-uniform filtering structures instead of conventional constant-k sections. Two circuit prototypes with Butterworth and Chebyshev filtering were designed using network synthesis method, and implemented in a 0.18μm digital CMOS technology. The Butterworth prototype achieved 11.7dB gain, 9GHz bandwidth, and -5dB/GHz roll-off. The Chebyshev one achieved 10dB gain, 8.5GHz bandwidth and -8dB/GHz roll-off.

关键词： Amplifiers (electronic)

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IEEE standards

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IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE 2006年第5期9卷 8-8页

作者： Hochberg, Rich Center for Engineering Systems Advanced Research Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge TN USA

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Nanocomputing with probabilistic logic

Nanocomputing with probabilistic logic

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2006 6th IEEE Conference on Nanotechnology, IEEE-NANO 2006

作者： Fortes, José A. B. Advanced Computing and Information Systems Laboratory Department of Electrical and Computer Engineering University of Florida Gainesville FL United States

ISBN: (纸本)1424400783

This presentation considers the impact on logic design and computing of the fundamental unreliability of nanoscale device technologies. In general, these technologies will provide implementations of logic gates and circuits where logic levels are "0" or "1" with some probability related to the error rates of gates and interconnect. In this context, reliable circuit design becomes a problem of maximizing the probability of the correct logic levels of the output of the function implemented by the circuit for the relevant inputs. This presentation reviews some recent results and proposes new ideas for the characterization and design of probabilistic logic. Since the early days of computing it has been well known that the design of reliable arbitrary logic circuits is only possible if individual gates have error rates below some threshold which varies with gate functionality. Using bifurcation analysis of probabilistic gate models, thresholds for different types of gates are derived and their implications for logic design are revisited. Similar techniques are used to analyze multi-gate circuits and the functions they implement. The resulting thresholds provide reliability bounds for the circuits. Also considered are several proposed models for either analyzing reliability or maximizing it. Reference is also made to circuits designed to implement probabilistic computations. © 2006 IEEE.

关键词： Nanoelectronics

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Behavior of bulk high-temperature superconductors of finite thickness subjected to crossed magnetic fields: Experiment and model

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Physical Review B 2007年第17期75卷 174515-174515页

作者： Ph. Vanderbemden Z. Hong T. A. Coombs S. Denis M. Ausloos J. Schwartz I. B. Rutel N. Hari Babu D. A. Cardwell A. M. Campbell SUPRATECS and Department of Electrical Engineering and Computer Science B28 Sart-Tilman B-4000 Liège Belgium Centre for Advanced Photonics and Electronics Engineering Department University of Cambridge 9 JJ Thomson Avenue Cambridge CB3 0FA United Kingdom SUPRATECS Communication Information Systems & Sensors (CISS) Department Royal Military Academy of Belgium 30 avenue de la Renaissance B-1000 Bruxelles Belgium SUPRATECS and Physics Institute B5 University of Liège Sart-Tilman B-4000 Liège Belgium National High Magnetic Field Laboratory Florida State University 1800 E. Paul Dirac Drive Tallahassee Florida 32310 USA IRC in Superconductivity University of Cambridge Madingley Road Cambridge CB3 OHE United Kingdom

Crossed-magnetic-field effects on bulk high-temperature superconductors have been studied both experimentally and numerically. The sample geometry investigated involves finite-size effects along both (crossed-)magnetic-field directions. The experiments were carried out on bulk melt-processed Y-Ba-Cu-O single domains that had been premagnetized with the applied field parallel to their shortest direction (i.e., the c axis) and then subjected to several cycles of the application of a transverse magnetic field parallel to the sample ab plane. The magnetic properties were measured using orthogonal pickup coils, a Hall probe placed against the sample surface, and magneto-optical imaging. We show that all principal features of the experimental data can be reproduced qualitatively using a two-dimensional finite-element numerical model based on an E−J power law and in which the current density flows perpendicularly to the plane within which the two components of magnetic field are varied. The results of this study suggest that the suppression of the magnetic moment under the action of a transverse field can be predicted successfully by ignoring the existence of flux-free configurations or flux-cutting effects. These investigations show that the observed decay in magnetization results from the intricate modification of current distribution within the sample cross section. The current amplitude is altered significantly only if a field-dependent critical current density Jc(B) is assumed. Our model is shown to be quite appropriate to describe the cross-flow effects in bulk superconductors. It is also shown that this model does not predict any saturation of the magnetic induction, even after a large number (∼100) of transverse field cycles. These features are shown to be consistent with the experimental data.

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Implementing quantum genetic algorithms: A solution based on Grover's algorithm

Implementing quantum genetic algorithms: A solution based on...

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3rd Conference on Computing Frontiers 2006, CF '06

作者： Udrescu, Mihai Prodan, Lucian VlǍduţiu, Mircea Advanced Computing Systems and Architectures Laboratory Computer Engineering Department University Politehnica of Timişoara 2 V. Parvan Boulevard Timişoara 300223 Romania

ISBN: (纸本)1595933026

This paper presents a new methodology for running Genetic Algorithms on a Quantum computer. To the best of our knowledge and according to reference [6] there are no feasible solutions for the implementation of the Quantum Genetic Algorithms (QGAs). We present a new perspective on how to build the corresponding QGA architecture. It turns out that the genetic strategy is not particularly helpful in our quantum computation approach;therefore our solution consists of designing a special-purpose oracle that will work with a modified version of an already known algorithm (maximum finding [1]), in order to reduce the QGAs to a Grover search. Quantum computation offers incentives for this approach, due to the fact that the qubit representation of the chromosome can encode the entire population as a superposition of basis-state values. Copyright 2006 ACM.

关键词： Genetic algorithms

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Wake acoustic analysis and image decomposition via beamforming of microphone signal projections on wavelet subspaces

Wake acoustic analysis and image decomposition via beamformi...

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12th AIAA/CEAS Aeroacoustics Conference

作者： Wassaf, Hadi S. Yan, Zhang Ibe, Oliver C. John A. Volpe National Transportation Systems Center Cambridge MA 02142 Jet Propulsion Laboratory Pasadena CA 91109 University of Massachusetts Lowell Lowell MA 01854 Advanced Communication Navigation and Surveillance Division RTV-4A Interferometry and Advanced Optical Systems Section Department of Electrical and Computer Engineering

ISBN: (纸本)1563478099

This paper describes the integration of wavelet analysis and time-domain beamforming of microphone array output signals for analyzing the acoustic emissions from airplane generated wake vortices. This integrated process provides visual and quantitative simultaneous information about the wake signal composition and array resolution for a particular wavelet subspace during a time interval, T. In the results section, an example is given on how image processing algorithms might be used to automate the extraction of this information and select the wavelet subspaces from which to perform image reconstruction. This process begins with the projection of all the microphone signals on wavelet multi-resolution subspaces. The projections of these signals on the same wavelet subspace or scale are then beamformed to produce an image of the wake corresponding to that particular scale. Therefore for each time interval T, the process produces a number of images equal to that of the wavelet scales. This is equivalent to a more conventional Fourier-based idea of filtering the microphone signals with band-pass liters having non-uniform bandwidths then beamform in different sub-bands, but offers greater flexibility and enhanced computational speed. Results from both approaches will be shown, which ultimately illustrate the advantages of wavelet analysis over that of the Fourier-based analysis. Amongst the advantages are the speed of the decomposition and ease of the image reconstruction from selected subspaces aided by the perfect reconstruction and orthogonality properties of wavelet analysis.

关键词： Acoustic emissions

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