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A floating-point FPGA-based self-tuning regulator

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2006年第2期53卷 693-704页

作者： Salcic, Z Cao, JY Nguang, SK Univ Auckland Dept Elect & Comp Engn Auckland 1020 New Zealand

Recursive-least-square (RLS) algorithm is widely used in many areas with real-time implementation using digital signal processors. In this paper, the authors present a pure hardware implementation of a self-tuning regulator (STR) that uses a real-time RLS algorithm as the parameter estimator. The STR contains a controller design circuit and a controller circuit. Due to RLS computation-precision and dynamic-range requirements, the hardware implementation uses a floating-point format. The floating-point processing elements presented in this paper use parameterized design, where the number of exponents and mantissa bits can be changed as the data range and the accuracy of a specific application require. The strategies for overcoming the covariance matrix asymmetrical problem during the hardware computation and the covariance matrix resetting is introduced when the system is poorly exciting are presented. The design was verified with real-time experiments using a new testbed. The experiment results are presented.

关键词： digital signal processor (DSP) estimation algorithm field-programmable gate array (FPGA) floating-point arithmetic floating-point format recursive least squares (RLS) self-tuning regulator (STR)

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Dynamic absolute distance measurement by frequency sweeping interferometry based Doppler beat frequency tracking model

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OPTICS COMMUNICATIONS 2019年 430卷 163-169页

作者： Jia, Xingyu Liu, Zhigang Deng, Zhongwen Deng, Wen Wang, Zhiyong Zhen, Zhilong Xi An Jiao Tong Univ Key Lab Modern Design & Rotor Bearing Syst Minist Educ Xian 710049 Shaanxi Peoples R China

We propose a frequency-sweeping interferometry (FSI) with single external cavity diode laser that can be used to measure the absolute distances of a dynamic target. Generally, the FSI-Doppler effect induced by target drift restricts the measurement accuracy severely, but the Doppler effect can also be used to measure the actual movement during optical frequency sweeps. Thus, a mathematical model of the Doppler effect in FSI is presented and a novel FSI method based on Doppler beat frequency tracking model is proposed to realize the absolute distance measurement of a dynamic target. The method was verified successfully by measuring vibrating targets of 50 similar to 5000 Hz at 38 mm in the laboratory.

关键词： Interferometry Absolute distance measurement Doppler effect estimation algorithm

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Computation and analysis of image motion: A synopsis of current problems and methods

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INTERNATIONAL JOURNAL OF COMPUTER VISION 1996年第1期19卷 29-55页

作者： Mitiche, A Bouthemy, P INST NATL RECH INFORMAT & AUTOMAT IRISA F-35042 RENNES FRANCE

The goal of this paper is to offer a structured synopsis of the problems in image motion computation and analysis, and of the methods proposed, exposing the underlying models and supporting assumptions. A sufficient number of pointers to the literature will be given, concentrating mostly on recent contributions. Emphasis will be on the detection, measurement and segmentation of image motion. Tracking, and deformable motion isssues will be also addressed. Finally, a number of related questions which could require more investigations will be presented.

关键词： Optical-flow fields Closed-form solutions Active shape models Visual-motion Moving-objects Vector-fields Smoothness constraints estimation algorithm Posed problems Feature points Closed-form solutions Active shape model Feature Points images

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STATE-SPACE BASED DUAL-RATE SELF-TUNING

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AUTOMATICA 1994年第12期30卷 1999-2007页

作者： AHMED, MS [a]Department of Electrical and Computer Engineering University of Michigan Dearborn MI 48128 U.S.A.

A state space based dual-rate self-tuning algorithm is proposed for the case where the output sampling rate is slower than the input update rate, A state space innovation model suitable for dual-rate self-tuning control is derived. The parameters of the innovation model together with the states are estimated by a recursive prediction error estimator. The control strategy has been based on a pole restriction principle. Simulation studies are presented to establish the practical usefulness of the algorithm.

关键词： ADAPTIVE CONTROL SELF-TUNING CONTROL COMPUTER CONTROLLED SYSTEM STOCHASTIC SYSTEM estimation algorithm STATE FEEDBACK

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Epidemic Source Detection over Dynamic Networks

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ELECTRONICS 2020年第6期9卷 1018页

作者： Choi, Jaeyoung Gachon Univ Dept AI Software 1342 Seongnamdaero Seongnam Si 13120 Gyeongi Do South Korea

Epidemic source detection is one of the most crucial problems in statistical inference. For example, currently, the debate continues to reveal when and where the first spread of COVID-19 occured. For this problem, most of the works have assumed a static network topology, that is, the connections between nodes do not change over time. This is impractical because many nodes have some mobility in the network, or the connections can be changed. In this paper, we focus on the dynamic network, in the sense that the node connectivity varies over time. We first introduce a simple dynamic model, named k-flip dynamic such that k > 0 connections in the network may be changed with some probability at each time. Next, we design a proper estimation algorithm using some investigation for the contact information between infected nodes, named dynamic network source estimation (DNSE)(k) for the dynamic model. We perform various simulations for the algorithm compared to several existing source estimation methods. Our results show that the proposed algorithm outperforms and is efficient for finding the epidemic source compared to other methods. Further, we see that the detection probability for our proposed algorithm can be above 45% when we use budget to investigate the contact information from the infected nodes under some practical setting ofk.

关键词： epidemic source detection dynamic network diffusion model estimation algorithm

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Metrics of Algebraic Closures in Pattern Recognition Problems with Two Nonoverlapping Classes

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COMPUTATIONAL MATHEMATICS AND MATHEMATICAL PHYSICS 2008年第5期48卷 866-876页

作者： D'yakonov, A. G. Moscow MV Lomonosov State Univ Fac Computat Math & Cybernet Moscow 119992 Russia

It is shown that, in the pattern recognition problem with two nonoverlapping classes, the matrices of estimates of the object closeness are described by a metric. The transition to the algebraic closure of the model of recognizing operators of finite degree corresponds to the application of a special transformation of this metric. It is proved that the minimal degree correct algorithm can be found as a polynomial of a special form. A simple criterion for testing classification implementations is obtained.

关键词： pattern recognition estimation algorithm matrices of estimates correct algorithm algebra over algorithms metric Gram's matrix minimal degree

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An extended instrument variable approach for nonparametric LPV model identification

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IFAC-PapersOnLine 2018年第26期51卷 81-86页

作者： Lima, Marcelo M.L. Romano, Rodrigo A. dos Santos, Paulo Lopes Pait, Felipe Escola de Engenharia do Instituto Mauá de Tecnologia Praça Mauá n.1 São Caetano do Sul09580-900 Brazil Faculdade de Engenharia da Universidade do Porto Portugal Rua do Dr Roberto Frias s/n 4200–465 Porto Portugal Escola Politécnica da Universidade de São Paulo Av Luciano Gualberto n.380 05508–010 São Paulo Brazil

Linear parameter varying models (LPV) have proven to be effective to describe non–linearities and time–varying behaviors. In this work, a new non-parametric estimation algorithm for state-space LPV models based on support vector machines is presented. This technique allows the functional dependence between the model coefficients and the scheduling signal to be “learned” from the input and output data. The proposed algorithm is formulated in the context of instrumental (IV) estimators, in order to obtain consistent estimates for general noise conditions. The method is based on a canonical state–space representation and admits a predictor form that has shown to be suitable for system identification, as it leads to a convenient regression form. In addition, this predictor has an inherent filtering feature. In the context of vector support machines, such filtering mechanism leads to two–dimensional data processing, which can be used to decrease the variance of estimates due to noisy data. The performance of the proposed approach is evaluated from simulated data subject to different noise scenarios. The technique was able to reduce the error due to the variance of the estimator in most of the analyzed scenarios. © 2018

关键词： Parameter estimation Data handling Identification (control systems) Learning algorithms Religious buildings Vector spaces estimation algorithm Filtering mechanism Functional dependence Linear parameter varying models Lpv model identifications Non parametric estimations Parametric identification Variance of estimates

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Piezo-actuated vibration disturbance mirror for investigating accelerometer-based tip-tilt reconstruction in large telescopes

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IFAC-PapersOnLine 2016年第21期49卷 361-366页

作者： Glück, Martin Pott, Jörg-Uwe Sawodny, Oliver University of Stuttgart Waldburgstr. 17/19 Stuttgart70563 Germany Königstuhl 17 Heidelberg69117 Germany

The optical performance of large telescopes depends not only on the correction of atmospheric turbulences but also on the suppression of structural vibrations. Nowadays, these disturbances are compensated by Adaptive Optics (AO) systems. Especially for the vibration suppression new control concepts are developed. A well-known method is a state feedback controller. However, for observations with natural faint guide stars the integration time of the wavefront sensor is increased and therefore the bandwidth of the control loop is not sufficient for a fully vibration compensation. Hence, we want to avoid this problem by using an Accelerometer-based Disturbance Feedforward control (DFF), which is independent of the integration time. The vibrations are measured at the relevant telescope mirrors and the tip-tilt modes are reconstructed for the actuator control signals. For investigating the DFF a laboratory setup is built. The setup consists of a classical AO system and additional designed tip-tilt mirrors for simulating and compensating the vibrations. Several accelerometer are mounted at the disturbance mirror. Based on the measured accelerations two position estimators are investigated in order to use them in real telescope applications. © 2016

关键词： Adaptive optics Accelerometers Actuators Atmospheric turbulence Feedforward control Mirrors Signal reconstruction State feedback Structural dynamics Telescopes Vibration measurement Adaptive optics systems estimation algorithm State feedback controller Structural vibrations Telescope applications Vibration compensation Vibration disturbances Vibration suppression

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Proportional-type non-linear excitation controller with power angle reference estimator for single-machine infinite-bus power system

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IET GENERATION TRANSMISSION & DISTRIBUTION 2019年第18期13卷 4029-4036页

作者： Kim, Seok-Kyoon Hanbat Natl Univ Dept Creat Convergence Engn Daejeon 34158 South Korea

This study suggests a non-linear control algorithm for the exciter controlling a single-machine infinite-bus system, considering the non-linear dynamics with parameter and sudden input power variations. This study provides three contributions: (i) an estimation algorithm is designed to estimate the power angle operating point for the terminal voltage to be regulated to its desired value, incorporating the disturbance observer (DOB);(ii) a DOB-based proportional-type non-linear stabilising algorithm is systematically derived using the estimated power angle operating point;and (iii) it is rigorously shown that the proposed proportional-type non-linear controller always removes the steady-state errors without integral actions for error variables. The simulation results confirm the effectiveness of the proposed technique under several transmission line fault scenarios.

关键词： power system stability power system control power transmission faults stability observers nonlinear control systems control system synthesis sudden input power variations estimation algorithm DOB-based proportional-type nonlinear stabilising algorithm estimated power angle operating point proportional-type nonlinear controller proportional-type nonlinear excitation controller power angle reference estimator infinite-bus power system nonlinear control algorithm single-machine infinite-bus system nonlinear dynamics

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Improved Accuracy of Chlorophyll-a Concentration Estimates from MODIS Imagery Using a Two-Band Ratio algorithm and Geostatistics: As Applied to the Monitoring of Eutrophication Processes over Tien Yen Bay (Northern Vietnam)

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REMOTE SENSING 2014年第1期6卷 421-442页

作者： Nguyen Thi Thu Ha Koike, Katsuaki Mai Trong Nhuan Vietnam Natl Univ VNU Univ Sci Fac Geol Hanoi 10000 Vietnam Kyoto Univ Grad Sch Engn Dept Urban Management Kyoto 6158540 Japan

Sea eutrophication is a natural process of water enrichment caused by increased nutrient loading that severely affects coastal ecosystems by decreasing water quality. The degree of eutrophication can be assessed by chlorophyll-a concentration. This study aims to develop a remote sensing method suitable for estimating chlorophyll-a concentrations in tropical coastal waters with abundant phytoplankton using Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra imagery and to improve the spatial resolution of MODIS/Terra-based estimation from 1 km to 100 m by geostatistics. A model based on the ratio of green and blue band reflectance (rGBr) is proposed considering the bio-optical property of chlorophyll-a. Tien Yen Bay in northern Vietnam, a typical phytoplankton-rich coastal area, was selected as a case study site. The superiority of rGBr over two existing representative models, based on the blue-green band ratio and the red-near infrared band ratio, was demonstrated by a high correlation of the estimated chlorophyll-a concentrations at 40 sites with values measured in situ. Ordinary kriging was then shown to be highly capable of predicting the concentration for regions of the image covered by clouds and, thus, without sea surface data. Resultant space-time maps of concentrations over a year clarified that Tien Yen Bay is characterized by natural eutrophic waters, because the average of chlorophyll-a concentrations exceeded 10 mg/m(3) in the summer. The temporal changes of chlorophyll-a concentrations were consistent with average monthly air temperatures and precipitation. Consequently, a combination of rGBr and ordinary kriging can effectively monitor water quality in tropical shallow waters.

关键词： bio-optical properties water quality estimation algorithm phytoplankton ordinary kriging

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