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Absolute M _split estimation as an alternative for robust M-estimation

Robert Duchnowski Patrycja Wyszkowska

Advances in Geodesy and Geoinformation | 2022 | vol. 71 | No 1 | e17 | DOI: 10.24425/gac.2022.141170

Keywords laser scanning robust estimation M-estimation absolute Msplit estimation

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Abstract

The problem of outlying observations is very well-known in the surveying data processing. Outliers might have several sources, different magnitudes, and shares within the whole observation set. It means that it is not possible to propose one universal method to deal with such observations. There are two general approaches in such a context: data cleaning or robust estimation. For example, the robust M-estimation has found many practical applications. However, there are other options, such as R-estimation or the absolute M _split estimation. The latter method was created to be less sensitive to outliers than the squared M _splitestimation (the basic variant of Msplit estimation). From the theoretical point of view, the absolute M _split estimation cannot be classified as a robust method; however, it was proved that it could be used in such a context under certain conditions. The paper presents the primary comparison between that method and a conventional robust M-estimation. The results show that the absolute M _split estimation predominates over the classical methods, especially when the percentage of outliers is high. Thus, that method might be used to process LiDAR data, including mismeasured points. Processing synthetic data from terrestrial laser scanning or airborne laser scanning confirms that the absolute M _{split /_{estimation can deal with outliers sufficiently.}}

Authors and Affiliations

Robert Duchnowski

1

e-mail:

ORCID:

Patrycja Wyszkowska

1

e-mail:

ORCID:

University of Warmia and Mazury, Olsztyn, Poland

Two variants of M _split estimation – similarities and differences

Patrycja Wyszkowska Robert Duchnowski

Advances in Geodesy and Geoinformation | 2022 | vol. 71 | No 1 | e22 | DOI: 10.24425/gac.2022.141175

Keywords accuracy influence function absolute Msplit estimation squared Msplit estimation

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Abstract

M _split estimation is a novel method developed to process observation sets that include two (or more) observation aggregations. The main objective of the method is to estimate the location parameters of each aggregation without any preliminary assumption concerning the division of the observation set into respective subsets. Up to now, two different variants of M _split estimation have been derived. The first and basic variant is the squared M _split estimation, which can be derived from the assumption about the normal distribution of observations. The second variant is the absolute M _splitestimation, which generally refers to the least absolute deviation method. The main objective of the paper is to compare both variants of M _split estimation by showing similarities and differences between the methods. The main dissimilarity stems from the different influence functions, making the absolute M _split estimation less sensitive to gross errors of moderate magnitude. The empirical analyses presented confirm that conclusion and show that the accuracy of the methods is similar, in general. The absolute M _split estimation is more accurate than the squared M _split estimation for less accurate observations. In contrast, the squared M _split estimation is more accurate when the number of observations in aggregations differs much. Concerning all advantages and disadvantages of M _split estimation variants, we recommend using the absolute M _split estimation in most geodetic applications.

Authors and Affiliations

Patrycja Wyszkowska

1

e-mail:

ORCID:

Robert Duchnowski

1

e-mail:

ORCID:

University of Warmia and Mazury, Olsztyn, Poland

Integrated analysis of costs and amount of greenhouse gases emissions during the building lifecycle

Krzysztof Zima

Archives of Civil Engineering | 2021 | vol. 67 | No 2 | 413-423 | DOI: 10.24425/ace.2021.137176

Keywords cost estimation carbon footprint construction

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Abstract

More than 6 billion square metres of new buildings are built each year. This is about 1.2 million buildings. If we translate these figures into carbon footprint (CF) generated during the construction, it will be approximately 3.7 billion tons of carbon dioxide. The contractors all over the world – also in Poland – decide to calculate the carbon footprint for various reasons, but mostly they are compelled to do so by the market. The analysis of costs and emissions of greenhouse gases for individual phases of the construction system allows implementing solutions and preventing a negative impact on the environment without increasing the construction costs. The share of each phase in the amount of produced carbon for construction and use of the building depends mainly on the used materials and applied design solutions. Hence, the materials and solutions with lesser carbon footprint should be used. It can be achieved by using natural materials or materials which do not need much energy to be produced. The author will attempt to outline this idea and present examples of integrated analysis of costs and amount of carbon footprint during the building lifecycle.

Authors and Affiliations

Krzysztof Zima

1

e-mail:

ORCID:

DSc., PhD., Eng., Prof. CUT, Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Krakow, Poland

Theoretical geodesy

Andrzej Borkowski Wiesław Kosek

Geodesy and Cartography | 2015 | vol. 64 | No 2 | DOI: 10.1515/geocart-2015-0015

Keywords M-estimation robust estimation reliability time series polar motion

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Abstract

The paper presents a summary of research activities concerning theoretical geodesy performed in Poland in the period of 2011–2014. It contains the results of research on new methods of the parameter estimation, a study on robustness properties of the M-estimation, control network and deformation analysis, and geodetic time series analysis. The main achievements in the geodetic parameter estimation involve a new model of the M-estimation with probabilistic models of geodetic observations, a new Shift-M split estimation, which allows to estimate a vector of parameter differences and the Shift- M split (+) that is a generalisation of Shift- M split estimation if the design matrix A of a functional model has not a full column rank. The new algorithms of the coordinates conversion between the Cartesian and geodetic coordinates, both on the rotational and triaxial ellipsoid can be mentioned as a highlights of the research of the last four years. New parameter estimation models developed have been adopted and successfully applied to the control network and deformation analysis. New algorithms based on the wavelet, Fourier and Hilbert transforms were applied to find time-frequency characteristics of geodetic and geophysical time series as well as time-frequency relations between them. Statistical properties of these time series are also presented using different statistical tests as well as 2 nd , 3 rd and 4 th moments about the mean. The new forecasts methods are presented which enable prediction of the considered time series in different frequency bands.

Authors and Affiliations

Andrzej Borkowski

Wiesław Kosek

The problem of solving systems of linear equations by means of neural networks

Józef Gil

Geodesy and Cartography | 2006 | vol. 55 | No 2 | 77-94

Keywords Linear equations robust estimation neural networks

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Abstract

The paper addresses the problem of solving overdetermined systems of linear equations by means of methods of robust estimations, which eliminate the effect of outliers on the estimation results. The process of estimating a vector of parameters was accomplished by means of circular in structure neural networks. Formulating the problem in the aspect of a method for estimating parameters requires formulating an energy function (objective function) whose form was modified by means of a determined weighting function. In the final part of the paper the effectiveness of the methods described was evaluated in terms of controlling and diagnosing a geodetic observation system. The article is merely an introduction to a broadly understood problem of geodetic uses of robust estimators.

Authors and Affiliations

Józef Gil

A robust method of quasigeoid modelling in Poland based on GPS/levelling data with support of gravity data

Edward Osada Jan Kryński Magdalena Owczarek

Geodesy and Cartography | 2005 | vol. 54 | No 3 | 99-117

Keywords quasigeoid GPS/levelling collocations robust estimation

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Abstract

An increased use of global navigation techniques for positioning, and in particular for height determination, led to a growing need for precise models of height reference surface, i.e. geoid or quasigeoid. Geoid or quasigeoid heights at a cm accuracy level, provided on growing number ofGPS/levelling sites, can not only be used for quality control of gravimetric geoid but they also can be integrated with gravity data for geoid/quasigeoid modelling. Such a model is of particular use for surveying practice. A method of quasigeoid modelling based on GPS/levelling data with support of geopotential model and gravity data was developed. The components of height anomaly are modelled with the deterministic part that consists of height anomaly based on EGM96 geopotential model and Molodensky's integral, as well as the polynomial representing trend, and from the stochastic part represented by the isotropic covariance function. Model parameters, i.e. polynomial coefficients and covariance function parameters are determined in a single process of robust estimation, resistant to the outlying measurements. The method was verified using almost a thousand height anomalies from the sites of the EUREF-POL, POLREF, EUVN'97 and WSSG (Military Satellite Geodetic Network) networks in Poland as well as geopotential model refined with gravity data in l' x l' grid. The estimated average mean square error of quasigeoid height is at the level of O.Ol m. The outlying measurements were efficiently detected.

Authors and Affiliations

Edward Osada

Jan Kryński

e-mail:

ORCID:

Magdalena Owczarek

The use of statistical analysis for estimation of positional accuracy of large-scale digital maps

Adam Doskocz

Geodesy and Cartography | 2005 | vol. 54 | No 3 | 131-150

Keywords Digital map accuracy estimation statistical analysis

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Abstract

The paper presents estimation of positional accuracy of digital maps using statistical analysis. Investigations have been performed for four large-scale digital maps made using different methods of producing digital map data: new total station survey (object A), re-calculation of previous direct measurements (orthogonal and polar surveys) (object B), manual vectorisation of a raster orthophotomap image (object C) and graphical-and-digital processing of analogue maps (object D). Analysis has been performed for large statistical samples of sets of vectors of shift t: L of control points and their components, i.e. true errors t: x, t: r of increments of co-ordinates. In the case of a map produced by means of new survey with an electronic tacheometer, the true errors were represented by differences between co-ordinates of control points obtained from two separate set outs. In the case of other methods of data collection for digital map production true errors were represented by differences of co-ordinates acquired from an investigated map and co-ordinates calculated from new direct surveys.

Authors and Affiliations

Adam Doskocz

Evaluation of the Sedimentation Process in the Thickener by Using the Parameters of Longitudinal Ultrasonic Oscillations and Lamb Waves

Vladimir Morkun Natalia Morkun Vitaliy Tron Oleksandra Serdiuk Alona Haponenko

Archives of Acoustics | 2023 | vol. 48 | No 4 | 539-548 | DOI: 10.24425/aoa.2023.146819

Keywords thickener ultrasound automatic control modeling parameter estimation

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Abstract

Water is widely used in the mining industry, particularly in mineral enrichment processes. In the process of magnetic separation or flotation of crushed ore, a concentrate (an enriched product), and tailings (a product with a low content of a useful component) are obtained. One of the main tasks of enrichment processes is the efficient use of water resources. This is achieved by reclaiming and subsequent reusing water contained in ore beneficiation products by extracting it in industrial thickeners. Optimizing this process makes it possible to reduce water usage in the mining industry, reduce costs of mineral enrichment processes, and address extremely urgent environmental protection problems. To evaluate the process of sedimentation of the solid phase in the pulp within the thickener, measurements of parameters of longitudinal ultrasonic oscillations and Lamb waves that have traveled a fixed distance in the pulp and along the measuring surface in contact with it are used. The proposed approach allows for the consideration of pulp density, particle size of the solid phase in the ore material and the dynamics of changes in these parameters in the thickener at the initial stage of the sedimentation process. Based on the obtained values, adjustments can be made to the characteristics of its initial product, leading to reduced water usage and minimized loss of a useful component.

Authors and Affiliations

Vladimir Morkun

1

Natalia Morkun

1

Vitaliy Tron

1

Oleksandra Serdiuk

1

Alona Haponenko

1

Kryvyi Rih National University, Kryvyi Rih, Ukraine

Low altitude control for quadcopter using visual feedback

Konrad Urbański

Archives of Electrical Engineering | 2021 | vol. 70 | No 4 | 845-858 | DOI: 10.24425/aee.2021.138265

Keywords control estimation ground effect visual servoing

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Abstract

The paper presents the results of simulations and experiments in the field of control of the low damping and time delay oscillating system. This system includes a quadcopter hovering at a very low altitude, and the altitude is controlled. The time delay is introduced mainly by the remote control device. In order to handle the quadcopter at low altitudes, a proportional-integral controller with a negative proportional coefficient is used. Such an approach can provide good results in the case of an oscillating, low damped system. This method of steering, which uses a typical radio control transmitter, can be used on any commercially available leisure drone. Feedback is provided by a camera and algorithms of computer vision. The presented results were obtained experimentally using free flight – without a harness. Different types of controllers are used to control horizontal shift and altitude.

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Authors and Affiliations

Konrad Urbański

1

e-mail:

ORCID:

Institute of Robotics and Machine Intelligence, Poznan University of Technology, Piotrowo 3A str., 60-965 Poznan, Poland

An accurate and stable pose estimation method for planar cases considering the line constraints between every two points

Zhang Zimiao Zhang Hao Zhang Fumin Zhang Shihai

Metrology and Measurement Systems | 2023 | vol. 30 | No 2 | 235-258 | DOI: 10.24425/mms.2023.144871

Keywords pose estimation line constraints coplanar non-iterative

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Abstract

The current solutions for pose estimation problems using coplanar feature points (PnP problems) can be divided into non-iterative and iterative solutions. The accuracy, stability, and efficiency of iterative methods are unsatisfactory. Therefore, non-iterative methods have become more popular. However, the non-iterative methods only consider the correspondence of the feature points with their 2D projections. They ignore the constraints formed between feature points. This results in lower pose estimation accuracy and stability. In this work, we proposed an accurate and stable pose estimation method considering the line constraints between every two feature points. Our method has two steps. In the first step, we solved the pose non-iteratively, considering the correspondence of the 3D feature points with their 2D projections and the line constraints formed by every two feature points. In the second step, the pose was refined by minimizing the re-projection errors with one iteration, further improving accuracy and stability. Simulation and actual experiment results show that our method’s accuracy, stability, and computational efficiency are better than the other existing pose estimation methods. In the -45° to +45° measuring range, the maximum angle measurement error is no more than 0.039°, and the average angle measurement error is no more than 0.016°. In the 0 mm to 30 mm measuring range, the maximum displacement measurement error is no more than 0.049 mm, and the average displacement measurement error is no more than 0.012 mm. Compared to other current pose estimation methods, our method is the most efficient based on guaranteeing measurement accuracy and stability. Keywords:

Authors and Affiliations

Zhang Zimiao

1

Zhang Hao

1

Zhang Fumin

2

Zhang Shihai

1

School of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin, China
State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin, China

Modelling the One Channel Systems of a Delivery of Goods Provided by Unmanned Aerial Vehicles

Roman N. Kvyetnyy Yaroslav A. Kulyk Bogdan P. Knysh Yuryy Yu. Ivanov Andrzej Smolarz Orken Mamyrbaev Aimurat Burlibayev

International Journal of Electronics and Telecommunications | 2020 | vol. 66 | No 3 | 487-492 | DOI: 10.24425/ijet.2020.134003

Keywords signal processing window transformation multiwindow spectrum estimation

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Abstract

In this article is revealed the systems of a good delivery witch implement unmanned aerial vehicles during providing the service. the one channel systems of a goods delivery are a goal of this research work. the close analysing of their functional features, the classification, the types and parameters of different systems from this band are presented. in addition, the modelling of the different types of the one channel systems of goods delivery are has done.

Authors and Affiliations

Roman N. Kvyetnyy

Yaroslav A. Kulyk

Bogdan P. Knysh

Yuryy Yu. Ivanov

Andrzej Smolarz

Orken Mamyrbaev

Aimurat Burlibayev

Estimate final cost of roads using support vector machine

Musaab Falih Hasan Oday Hammody Khaldoon Satea Albayati

Archives of Civil Engineering | 2022 | vol. 68 | No 4 | 669-682 | DOI: 10.24425/ace.2022.143061

Keywords estimate cost roads support vector machine

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Abstract

The cost overrun in road construction projects in Iraq is one of the major problems that face the construction of new roads. To enable the concerned government agencies to predict the final cost of roads, the objective this paper suggested is to develop an early cost estimating model for road projects using a support vector machine based on (43) sets of bills of quantity collected in Baghdad city in Iraq. As cost estimates are required at the early stages of a project, consideration was given to the fact that the input data for the support vector machine model could be easily extracted from sketches or the project’s scope definition. The data were collected from contracts awarded by the Mayoralty of Baghdad for completed projects between 2010–2013. Mathematical equations were constructed using the Support Vector Machine Algorithm (SMO) technique. An average of accuracy (AA) (99.65%) and coefficient of determination (R2) (97.63%) for the model was achieved by the created prediction equations.

Authors and Affiliations

Musaab Falih Hasan

1

e-mail:

ORCID:

Oday Hammody

2

e-mail:

ORCID:

Khaldoon Satea Albayati

3

e-mail:

ORCID:

General Directorate of Education Baghdad Rusafa First, Ministry of Education, Iraq
Civil Engineering Department, University of Technology, Baghdad, Iraq
Iraqi Reinsurance Company, Ministry of Finance, Iraq

Biomass estimates of commercial fishes in the South Georgia region (by "swept area" method)

Mirosław Mucha

Polish Polar Research | 1984 | vol. 5 | No 1-2 | 107-111

Keywords Antarctic South Georgia commercial fishes estimates

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Abstract

The paper presents the results of biomass estimates of commercial fishes in the South Georgia region made by "swept area" method on the basis of catch statistics of a B-22 Polish trawler in the 1980/1981 season. Total biomass was estimated on about 11 x 104 t.

Authors and Affiliations

Mirosław Mucha

Application of fuzzy type II multi-layer Kalman filter for parameters identification of two-mass drive system

Kacper Śleszycki Karol Wróbel Krzysztof Szabat Seiichiro Katsura

Bulletin of the Polish Academy of Sciences Technical Sciences | 2023 | 71 | 4 | e146107 | DOI: 10.24425/bpasts.2023.146107

Keywords electrical drives torsional vibration state estimation Kalman filter multi-layer estimator

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Abstract

The paper describes a novel online identification algorithm for a two-mass drive system. The multi-layer extended Kalman Filter (MKF) is proposed in the paper. The proposed estimator has two layers. In the first one, three single extended Kalman filters (EKF) are placed. In the second layer, based on the incoming signals from the first layer, the final states and parameters of the two-mass system are calculated. In the considered drive system, the stiffness coefficient of the elastic shaft and the time constant of the load machine is estimated. To improve the quality of estimated states, an additional system based on II types of fuzzy sets is proposed. The application of fuzzy MKF allows for a shorter identification time, as well as improves the accuracy of estimated parameters. The identified parameters of the two-mass system are used to calculate the coefficients of the implemented control structure. Theoretical considerations are supported by simulations and experimental tests.

Authors and Affiliations

Kacper Śleszycki

1

e-mail:

ORCID:

Karol Wróbel

1

e-mail:

ORCID:

Krzysztof Szabat

1

e-mail:

ORCID:

Seiichiro Katsura

2

e-mail:

ORCID:

Wrocław University of Science and Technology, Institute of Electrical Machines, Drives and Measurements, Wrocław, Poland
Keio University, Department of System Design Engineering, Tokyo, Japan

Improving the Effectiveness of Maximum Score Estimators for Binary Regression Models

Marcin Owczarczuk

Central European Journal of Economic Modelling and Econometrics | 2015 | No 4 | 205-217 | DOI: 10.24425/cejeme.2015.119219

Keywords maximum score estimation Monte Carlo experiments effectiveness

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Abstract

Maximum score estimation is a class of semiparametric methods for the coefficients of regression models. Estimates are obtained by the maximization of the special function, called the score. In case of binary regression models it is the fraction of correctly classified observations. The aim of this article is to propose a modification to the score function. The modification allows to obtain smaller variances of estimators than the standard maximum score method without impacting other properties like consistency. The study consists of extensive Monte Carlo experiments.

Authors and Affiliations

Marcin Owczarczuk

Maximum score type estimators

Marcin Owczarczuk

Central European Journal of Economic Modelling and Econometrics | 2009 | No 1 | 7-34 | DOI: 10.24425/cejeme.2009.122220

Keywords maximum score estimation tobit truncated binomial semiparametric

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Abstract

This paper presents maximum score type estimators for linear, binomial, tobit and truncated regression models. These estimators estimate the normalized vector of slopes and do not provide the estimator of intercept, although it may appear in the model. Strong consistency is proved. In addition, in the case of truncated and tobit regression models, maximum score estimators allow restriction of the sample in order to make ordinary least squares method consistent.

Authors and Affiliations

Marcin Owczarczuk

Sensitivity of robust estimators applied in strategy for testing stability of reference points. EIF approach

Robert Duchnowski

Geodesy and Cartography | 2011 | vol. 60 | No 2 | DOI: 10.2478/v10277-012-0011-z

Keywords displacement stability R-estimation empirical influence function

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Abstract

In deformation analyses, it is important to find a stable reference frame and therefore the stability of the possible reference points must be controlled. There are several methods to test such stability. The paper’s objective is to examine one of such methods, namely the method based on application of R-estimation, for its sensitivity to gross errors. The method in question applies three robust estimators, however, it is not robust itself. The robustness of the method depends on the number of unstable points (the fewer unstable points there are, the more robust is the proposed method). Such property makes it important to know how the estimates applied and the strategy itself respond to a gross error. The empirical influence functions (EIF) can provide necessary information and help to understand the response of the strategy for a gross error. The paper presents examples of EIFs of the estimates, their application in the strategy and describes how important and useful is such knowledge in practice.

Authors and Affiliations

Robert Duchnowski

Sequential integration of measurements of navigational position parameters

Andrzej Banachowicz Adam Wolski

Geodesy and Cartography | 2010 | vol. 59 | No 1 | DOI: 10.2478/v10277-012-0008-7

Keywords navigational mathematics GPS sequential estimation maritime navigation

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Abstract

The sequential method of integrating navigational parameters obtained from non-simultaneous navigational measurements is presented. The proposed algorithm of position coordinates estimation is general and includes two modes of data processing – from simultaneous and non-simultaneous measurements. It can be used in hybrid receivers of radionavigation systems integrating non-homogeneous position lines or in integrated navigation systems, particularly in receivers combining the measurements of various satellite navigation systems.

Authors and Affiliations

Andrzej Banachowicz

Adam Wolski

Tissue Attenuation Estimation from Backscattered Ultrasound Using Spatial Compounding Technique - Preliminary Results

Andrzej Nowicki Ziemowit Klimonda Jerzy Litniewski

Archives of Acoustics | 2010 | vol. 35 | No 4 | 643-651 | DOI: 10.2478/v10168-010-0048-7

Keywords ultrasound attenuation estimation spatial compounding parametric imaging

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Abstract

The pathological states of biological tissue are often resulted in attenuation changes. Thus, information about attenuating properties of tissue is valuable for the physician and could be useful in ultrasonic diagnosis. We are currently developing a technique for parametric imaging of attenuation and we intend to apply it for in vivo characterization of tissue. The attenuation estimation method based on the echoes mean frequency changes due to tissue attenuation dispersion, is presented. The Doppler IQ technique was adopted to estimate the mean frequency directly from the raw RF data. The Singular Spectrum Analysis technique was used for the extraction of mean frequency trends. These trends were converted into attenuation distribution and finally the parametric images were computed. In order to reduce variation of attenuation estimates the spatial compounding method was applied. Operation and accuracy of attenuation extracting procedure was verified by calculating the attenuation coefficient distribution using the data from the tissue phantom (DFS, Denmark) with uniform echogenicity while attenuation coefficient underwent variation.

Authors and Affiliations

Andrzej Nowicki

Ziemowit Klimonda

Jerzy Litniewski

The applications of fixed-point theorem in optimisation problems

Krzysztof Chwastek

Archives of Electrical Engineering | 2012 | vol. 61 | No 2 June | 189-198 | DOI: 10.2478/v10171-012-0016-0

Keywords optimisation fixed-point theorem hysteresis parameter estimation

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Abstract

The fixed-point theorem is widely used in different engineering applications. The present paper focuses on its applications in optimisation. A Matlab toolbox, chich implements the branch-and-bound optimisation method based on the fixed-point theorem, is used for solving different real-life test problems, including estimation of model parameters for the Jiles-Atherton model.

Authors and Affiliations

Krzysztof Chwastek

Wrong transition and measurement models in power system state estimation

Piotr Kozierski Dariusz Horla Marcin Lis

Archives of Electrical Engineering | 2016 | vol. 65 | No 3 September | 559-574 | DOI: 10.1515/aee-2016-0040

Keywords particle filter estimation quality Population Monte Carlo

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Abstract

The influence of wrong information about transition and measurement models on estimation quality has been presented in the paper. Two methods of a particle filter, with and without the Population Monte Carlo modification, and also the extended and unscented Kalman filters methods have been compared. A small 5-bus power system has been used in simulations, which have been performed based on one data set, and this data set has been chosen from among 100 different – to draw the most general conclusions. Based on the obtained results it has been found that for the particle filter methods the implementation of the slightly higher standard deviation than the true value, usually increases the estimation quality. For the Kalman filters methods it has been concluded that optimal values of variances are equal to the true values.

Authors and Affiliations

Piotr Kozierski

Dariusz Horla

Marcin Lis

Estimators of induction motor electromechanical quantities built on the basis of a machine secondary multi-loop equivalent circuit

A. Kaplon G. Utrata J. Rolek

Archives of Electrical Engineering | 2014 | vol. 63 | No 2 June | 149-160 | DOI: 10.2478/aee-2014-0012

Keywords electrical machines induction motor sensorless control estimation

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Abstract

Contemporary sensorless AC drives require the use of electromechanical quantities estimation. The skin effect occurring in AC machines with solid secondary or with solid secondary elements causes machines of this type to be represented by equivalent circuits containing distributed elements, which makes the analysis of machine electrodynamic states more complicated and hinders the construction of relatively simple and effective estimators of electromechanical quantities. The variability of rotor parameters is modelled, with a good approximation, by the machine secondary multi-loop equivalent circuit with lumped elements. In this paper the construction procedure of electromechanical state variable estimators basing on this type of equivalent circuit will be presented. The simulation investigations of the created electromechanical quantities estimators, performed for the selected states of solid iron rotor AC machine operation will be shown as well.

Authors and Affiliations

A. Kaplon

G. Utrata

J. Rolek

A Velocity Measurement Method Based on Scaling Parameter Estimation of a Chaotic System

Lidong Liu Jifeng Hu Zishu He Chunlin Han Huiyong Li Jun Li

Metrology and Measurement Systems | 2011 | No 2 | 275-282 | DOI: 10.2478/v10178-011-0009-1

Keywords signal processing parameter estimation chaos synchronization

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Abstract

In this paper, we propose a new method of measuring the target velocity by estimating the scaling parameter of a chaos-generating system. First, we derive the relation between the target velocity and the scaling parameter of the chaos-generating system. Then a new method for scaling parameter estimation of the chaotic system is proposed by exploiting the chaotic synchronization property. Finally, numerical simulations show the effectiveness of the proposed method in target velocity measurement.

Authors and Affiliations

Lidong Liu

Jifeng Hu

Zishu He

Chunlin Han

Huiyong Li

Jun Li

Velocity Measurement using the Fdoa Method in Ground-Based Radio Navigation System

Jarosław Sadowski

Metrology and Measurement Systems | 2014 | No 2 | 363-376 | DOI: 10.2478/mms-2014-0031

Keywords radio navigation spread spectrum velocity estimation FDOA

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Abstract

Velocity is one of the main navigation parameters of moving objects. However some systems of position estimation using radio wave measurements cannot provide velocity data due to limitation of their performance. In this paper a velocity measurement method for the DS-CDMA radio navigation system is proposed, which does not require full synchronization of reference stations carrier frequencies. The article presents basics of FDOA (frequency difference of arrival) velocity measurements together with application of this method to an experimental radio navigation system called AEGIR and with some suggestions about the possibility to implement such FDOA measurements in other kinds of asynchronous DS-CDMA radio networks. The main part of this paper present results of performance evaluation of the proposed method, based on laboratory measurements

Authors and Affiliations

Jarosław Sadowski

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