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Search results for: ROTOR POSITION ESTIMATION
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Variable-fidelity shape optimization of dual-rotor wind turbines
PublicationPurpose Dual-rotor wind turbines (DRWTs) are a novel type of wind turbines that can capture more power than their single-rotor counterparts. Because their surrounding flow fields are complex, evaluating a DRWT design requires accurate predictive simulations, which incur high computational costs. Currently, there does not exist a design optimization framework for DRWTs. Since the design optimization of DRWTs requires numerous model...
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Improving Output Performance of the Ultrasonic Multicell Piezoelectric Motor by Development the Multi-Rotor Structure
PublicationIn recent years, many researches have been carried out on piezoelectric multi-rotor structures. This paper describes the analysis, development and experimental process of an ultrasonic multi-cell piezoelectric motor using a multi-rotor structure. In this design, three independent cells have been integrated into a mechatronic system. Analytical model and finite element method are used for modal and dynamic analysis of the proposed...
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Chapter 2: Modelling and analysis of rotor with magnetic bearing system
PublicationThe paper is concerned with rotor magnetic bearing system modelling. Such system is a relatively complex electromechanical system and can be considered as typical mechatronic one. The port-based modelling of physical systems has been used to obtain discrete-continuous model of considered system. Proposed approach enables to obtain reduced low-order lumped parameter representation of the system including gyroscopic interactions....
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A Novel Approach of Using Selected Unconventional Geodesic Methods of Estimation on VTS Areas
PublicationThe Vessel Traffic Service (VTS) systems belong to the fundamental tools used in ensuring a high level of safety across sea basins with heavy traffic, where the presence of navigational hazards poses a great risk of collision or a ship running aground. In order to determine the mutual location of ships, VTS systems obtain information from different facilities, such as coastal radar stations, AIS, and vision systems. Fixing a ship’s...
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Modifications at the C(5) position of pyrimidine nucleosides
PublicationThis review summarizes the state of knowledge on the chemical methods of C(5)-modifications of uridine and cytidine derivatives and may serve as a useful tool for synthetic chemists to choose an appropriate reaction protocol. The synthesis of 5-substituted uracil derivatives is gaining an increasing interest because of their possible applications in medicine and pharmacy. Modifications at the C(5) position of pyrimidine nucleosides...
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Estimation of Average Speed of Road Vehicles by Sound Intensity Analysis
PublicationConstant monitoring of road traffic is important part of modern smart city systems. The proposed method estimates average speed of road vehicles in the observation period, using a passive acoustic vector sensor. Speed estimation based on sound intensity analysis is a novel approach to the described problem. Sound intensity in two orthogonal axes is measured with a sensor placed alongside the road. Position of the apparent sound...
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Identification of Unstable Reference Points and Estimation of Displacements Using Squared Msplit Estimation
PublicationThe article presents a new version of the method for estimating parameters in a split functional model, which enables the determination of displacements of geodetic network points with constrained datum. The main aim of the study is to present theoretical foundations of Msplit CD estimation and its basic properties and possible applications. Particular attention was paid to the efficacy of the method in the context of geodetic...
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublicationEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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On the Matano Plane Position in Multicomponent Diffusion Couples
PublicationEven though several methods of diffusion analysis avoid a necessity for the Matano plane determination, the Matano plane locations are of interest in the multicomponent couples and when tracer experiments are performed. The positions of the Matano plane calculated from the concentration profiles should be exactly the same. However, due to experimental errors, the results can differ significantly. In the paper we consider Matano...
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Lattice filter based autoregressive spectrum estimation with joint model order and estimation bandwidth adaptation
PublicationThe problem of parametric, autoregressive model based estimation of a time-varying spectral density function of a nonstationary process is considered. It is shown that estimation results can be considerably improved if identification of the autoregressive model is carried out using the two-sided doubly exponentially weighted lattice algorithm which combines results yielded by two one-sided lattice algorithms running forward in...
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Innovative mobile method to determine railway track axis position in global coordinate system using position measurements performed with GNSS and fixed base of the measuring vehicle
PublicationThe shape of the railway track axis and its position in the global coordinate system are essential when defining design parameters of the railway. Correct reconstruction of these quantities is vital for both verifying the compliance of real track parameters with the design and for diagnosing, as all track deformations can also be defined as deviations of real parameters from their design values. The measurements of quantities related...
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Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
PublicationCoaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating...
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ESH Position Paper
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Thermal failure of a second rotor stage in heavy duty gas turbine
PublicationThe impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects...
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Analyses of influence of the rotor slots' skew on inductances of the stator and rotor windings of a squirell-cage asynchronous motor
PublicationObwodowy model matematyczny silnika asynchronicznego klatkowego ujęty w osiach naturalnych zawiera indukcyjności zależne od kąta położenia wirnika. Indukcyjności te zawierają szereg wyższych harmonicznych zależnych od układu geometrycznego strefy przyszczelinowej. Jednym z elementów tego układu jest skos żłobków wirnika. W referacie przedstawiono wyniki obliczeń elektromagnetycznych silnika magnesowanego pojedynczą cewką uzwojenia...
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Impact of rotor geometry optimization on the off-design ORC turbine performance
PublicationThe paper describes the method of CFD based Nelder-Mead optimization of a 10 kW single-stage axial turbine operating in an ORC system working on R7100. The total-to-static isentropic efficiency is defined as an objective function. Multi-point linear regression is carried out to determine the significance of the objective function arguments and to pick up the set of particular variables and characteristic quantities (e.g. flow angles)...
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Lattice filter based multivariate autoregressive spectral estimation with joint model order and estimation bandwidth adaptation
PublicationThe problem of parametric, autoregressive model based estimation of a time-varying spectral density function of a multivariate nonstationary process is considered. It is shown that estimation results can be considerably improved if identification of the autoregressive model is carried out using the two-sided doubly exponentially weighted lattice algorithm which combines results yielded by two one-sided lattice algorithms running...
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Evaluating the position of a mobile robot using accelerometer data
PublicationThis paper analyses the problem of determining the position of a robot using an accelerometer, which is an essential part of inertial measurement units (IMU). The information gained from such a gauge, however, requires double integration of sensor data. To assure an expected effect, a mathematical model of a low-cost accelerometer of the MEMS type is derived. Moreover, in order to improve the performance of positioning based on...
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The effect of a belt position in the spindle driving system on critical rotational speeds
PublicationThe aim of this paper was to examine how the belt pulley position affects critical rotational speeds of the modernized spindle of the sliding table saw Fx3. Methodology of determination of critical rotational speeds of the spindle in a function of the spindle design features and its driving system is presented. Spindles in these kind of machine tools are mainly driven with V-belts, and the pulleys on the spindles might be positioned:...
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Detection of Face Position and Orientation Using Depth Data
PublicationIn this paper an original approach is presented for real-time detection of user's face position and orientation based only on depth channel from a Microsoft Kinect sensor which can be used in facial analysis on scenes with poor lighting conditions where traditional algorithms based on optical channel may have failed. Thus the proposed approach can support, or even replace, algorithms based on optical channel or based on skeleton...
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Empirical analyses of robustness of the square Msplit estimation
PublicationThe paper presents Msplit estimation as an alternative to methods in the class of robust M-estimation. The analysis conducted showed that Msplit estimation is highly efficient in the identification of observations encumbered by gross errors, especially those of small or moderate values. The classical methods of robust estimation provide then unsatisfactory results. Msplit estimation also shows high robustness to single gross errors...
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Application of neural networks for identification of forcedness having effect on magnitude of turbine rotor vibration using rotor trajectory.
PublicationW pracy dokonano analizy zastosowania sieci neuronowych do wyznaczenia wartości wymuszeń wpływających na wielkość drgań wirnika używając trajektorii jako parametr określający drgania. Badania przeprowadzono na powietrznej, jednostopniowej turbinie modelowej. Przemieszczenia poziome i pionowe wirnika turbiny mierzono przy pomocy systemu pomiarowego i rejestrowano na oscyloskopie cyfrowym. Przeprowadzono pomiary trajektorii ruchu...
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DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
PublicationHydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital...
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New results on estimation bandwidth adaptation
PublicationThe problem of identification of a nonstationary autoregressive signal using non-causal estimation schemes is considered. Noncausal estimators can be used in applications that are not time-critical, i.e., do not require real-time processing. A new adaptive estimation bandwidth selection rule based on evaluation of pseudoprediction errors is proposed, allowing one to adjust tracking characteristics of noncausal estimators to unknown...
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Accuracy of Differential Phase Delay Estimation for GPS Spoofing Detection
PublicationGPS spoofing is an attack based on transmission of false signals to target receivers, in order to force the computation of incorrect time, position or velocity information. It is a threat which is recently considered with continuously growing awareness. There is a need for effective way of GPS spoofing detection. Many groups of methods are proposed in the literature. Spatial processing methods are considered to be robust in a wide...
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A Method for The Assessing of Reliability Characteristics Relevant to an Assumed Position-Fixing Accuracy in Navigational Positioning Systems
PublicationThis paper presents a method which makes it possible to determine reliability characteristics of navigational positioning systems, relevant to an assumed value of permissible error in position fixing. The method allows to calculate: availability , reliability as well as operation continuity of position fixing system for an assumed, determined on the basis of formal requirements - both worldwide and national, position-fixing accuracy....
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The Doppler effect in a bistatic system for determining the position of moving targets
PublicationThe article presents the theoretical analysis and the results of numerical calculations of the Doppler effect it occurs in a system designed to determine the position and speed of a moving target. The transmitter is the source of the signal and it emits a sinusoidal, acoustic and continuous wave. Signal reflected off a moving target is received by four hydrophones. Based on the signals, four Doppler shifts are determined and inserted...
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Estimation of electrode contact in capacitive ECG measurement
PublicationIn the paper a method of electrode’s contact estimation in capacitive electrocardiogram (CECG) is presented. Proposed solution allows estimation of contact quality for each individual electrode. This enables construction of multi-electrode CECG systems, where electrode pairs can be selected on the basis of the individual electrode contact quality.
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Variable Size Twin-Rotor Wind Turbine
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The influence of position of the post or its absence on the performance of the cable barrier system
PublicationRoad safety barriers are used to increase safety in potentially dangerous places on the roads. They are designed and installed on the roads to prevent any vehicle from getting outside the travelled way or from entering the opposite lane of the road. Barriers, which are used on European roads, have to undergo full scale crash tests according to the EN 1317 standards. Nowadays as a supplement to real crash tests, numerical simulations...
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Position in global value chains and wages in Central and Eastern European countries
PublicationThis paper examines the relationship between the relative position of industries in Global Value Chains (GVC) and wages in 10 Central and Eastern European countries. We combine GVC measures of global import intensity of production, upstreamness and the length of the value chain with micro-data on workers. We find that the wages of Central and Eastern European countries workers are higher when their industry is at the beginning...
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On Some Aspects of Fish Target Strength Estimation in Shallow Waters
PublicationThe theory of acoustic surveys for determining fish abundance are well established in fishery acoustics. The origins of the estimation are related to overcoming the problem of unknown position of target in the beam using statistical inversion. Although recently researchers use more sophisticated echosounders that provides more informative data allowing for direct solution it is known that the results are biased due to not ideally...
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Density smoothness estimation problem using a wavelet approach
PublicationIn this paper we consider a smoothness parameter estimation problem for a density function. The smoothness parameter of a function is defined in terms of Besov spaces. This paper is an extension of recent results (K. Dziedziul, M. Kucharska, B. Wolnik, Estimation of the smoothness parameter ). The construction of the estimator is based on wavelets coefficients. Although we believe that the effective estimation of the smoothness...
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A simplified channel estimation procedure for NB-IoT downlink
PublicationThis paper presents a low-complexity channel estimation procedure which is suitable for use in energy-efficient NB-IoT user equipment devices. The procedure is based on the well-established least squares scheme, followed by linear interpolation in the time domain and averaging in the frequency domain. The quality of channel estimation vs. signal-to-noise ratio is evaluated for two channel models and compared with the performance...
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Performance comparison of new modified gradient algorithm and Foy algorithm for iterative position calculation
PublicationIn the paper a new position calculation algorithm is presented. It is proposed for indoor environments and is called modified gradient algorithm. This algorithm is compared with well-known Foy algorithm. The comparative analysis is based on real distance measurements conducted in indoor environment.
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Estimators of covariance matrices in Msplit(q) estimation
PublicationThis paper proposes methods for the determination of covariance matrices of Msplit(q) estimators. The solutions presented here allow Msplit(q) estimation to be supplemented by the operations from the domain of accuracy analysis (especially that concerning estimators of parameters). Theoretical forms of covariance matrices of Msplit(q) estimators were established using the empirical influence functions and the equivalent covariance...
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Dataset Related Experimental Investigation of Chess Position Evaluation Using a Deep Neural Network
PublicationThe idea of training Articial Neural Networks to evaluate chess positions has been widely explored in the last ten years. In this paper we investigated dataset impact on chess position evaluation. We created two datasets with over 1.6 million unique chess positions each. In one of those we also included randomly generated positions resulting from consideration of potentially unpredictable chess moves. Each position was evaluated...
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Increasing the Utilization of dc-link Voltage of a Five-Leg VSI Based on Rotor Angle Control of Dual Induction Motors
PublicationThis paper introduces an increased utilization of the dc-link voltage of a five-leg voltage source inverter (VSI) based on the rotor flux angle control technique for dual induction motors, IM. The main purpose is to utilize additional abilities provided by a multi-motor drive system in limited operating conditions. Generally, a multi-motor drive system is widely used in electric vehicles (EVs), traction systems and in several industrial...
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A Simplistic Downlink Channel Estimation Method for NB-IoT
PublicationThis paper presents a downlink channel estimation method intended for a Narrowband Internet of Things (NB-IoT) access link. Due to its low computational complexity, this method is well suited for energy-efficient IoT devices, still providing acceptable reception quality in terms of signal-to-noise (SNR) performance. This paper describes the physical layer of NB-IoT within the scope of channel estimation, and also reviews existing...
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The influence of anchoring group position in ruthenium dye molecule on performance of dye-sensitized solar cells
PublicationThe effect of anchoring group position and, in consequence, the orientation of the ruthenium dye molecule on titania surface on the performance of dye-sensitized solar cells has been studied intensively. Three model ruthenium sensitizing dyes bearing carboxylic anchoring group in ortho, meta or para position were synthesized and well characterized by spectroscopic, electrochemical, photophysical and photochemical measurements....
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Estimation of DC motor parameters using a simple CMOS camera
PublicationDifferent components of control systems for mobile robots are based on dynamic models. In low-cost solutions such a robot is wheeled and equipped with DC motors, which have to be included in the model of the robot. The model is fairly simple but determination of its parameters needs not to be easy. For instance, DC motor parameters are typically identified indirectly using suitable measurements, concerning engine voltage, current,...
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Asynchronous Networked Estimation System for Continuous Time Stochastic Processes
PublicationIn this paper we examine an asynchronous networked estimation system for state estimation of continuous time stochastic processes. Such a system is comprised of several estimation nodes connected using a possibly incomplete communication graph. Each of the nodes uses a Kalman filter algorithm and data from a local sensor to compute local state estimates of the process under observation. It also performs data fusion of local estimates...
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DESIGN, DESIGN PROCESS AND ARCHITECT’S POSITION
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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IFE: NN-aided Instantaneous Pitch Estimation
PublicationPitch estimation is still an open issue in contemporary signal processing research. Nowadays, growing momentum of machine learning techniques application in the data-driven society allows for tackling this problem from a new perspective. This work leverages such an opportunity to propose a refined Instantaneous Frequency and power based pitch Estimator method called IFE. It incorporates deep neural network based pitch estimation...
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Neural networks in the diagnostics of induction motor rotor cages.
PublicationW środowisku Lab VIEW została stworzona aplikacja służąca do pomiaru, prezentacji i zapisu przebiegów widma prądu stojana z uwzględnieniem potrzeb pomiarowych występujących podczas badania wirników silników indukcyjnych przy użyciu sieci neuronowych. Utworzona na bazie zbioru uczącego sieć Kohonena z powodzeniem rozwiązała stawiany przed nią problem klasyfikacji widm prądu stojana, a co za tym idzie również diagnozy stanu...
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Theoretical investigations into flows in rotor blade shroud clearance
PublicationPrzedstawiono wyniki obliczeń programem Fluent przepływów w uszczelnieniu nadbandażowym stopnia turbinowego przy różnym mimośrodowym położeniu osi wirnika względem osi korpusu. Wyznaczone numerycznie rozkłady ciśnienia w uszczelnieniu i generowane tam siły aerodynamiczne porównano z rezultatem badań przeprowadzonych na powietrznej turbinie modelowej.
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Some results of experimental research into turbine rotor trajectory
PublicationPrzedstawiono rezultaty eksperymentalnych badań trajektorii wirnika turbinowego. Doświadczenia przeprowadzono na modelowej turbinie powietrznej przy różnych częstotliwościach obrotów wału i różnym obciążeniu wału względem osi korpusu.
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Application of neural networks for turbine rotor trajectory investigation.
PublicationW pracy przedstawiono rezultaty badań sieci neuronowych przewidujących trajektorię wirnika turbinowego uzyskanych ze stanowiska turbiny modelowej. Badania wykazały, iż sieci neuronowe wydają się być z powodzeniem zastosowane do przewidywania trajektorii ruchu wirnika turbiny. Najważniejszym zadaniem wydaje się poprawne określenie wektorów sygnałów wejściowych oraz wyjściowych jak również prawidłowe stworzenie sieci neuronowej....