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The effect of the motor filters on earth fault current waveform in circuits with variable speed drives
PublikacjaIn circuits with variable speed drives distorted earth fault current flows. Earth fault current distortion influences the threshold of ventricular fibrillation. This paper presents earth fault current distortion in circuits with variable speed drives when motor filter is used. Two types of motor filter are analyzed. For every type of filter the effect of earth fault current distortion on ventricular fibrillation is evaluated.
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The impact of wind farms with fixed speed induction generators on grid damping in Northern Ireland
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Estimating the Average Speed of Public Transport Vehicles Based on Traffic Control System Data
PublikacjaIntelligent Transport Systems are a valuable source of traffic information, covering both private and public vehicles. The main problem, however, is that very few studies are conducted to determine the speed of buses, trams and trolleys in urban networks in relation to traffic conditions. The paper investigates how ITS systems data could be used to model the speed of Public Transport vehicles. This is now possible thanks to the...
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Research and Analysis of High-Speed Data Transmission Radio Link Designed for Maritime Environment
PublikacjaIn these article, the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio...
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Research and analysis of high-speed data transmission radio link designed for maritime environment
PublikacjaIn these article the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio...
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Impact of digital signal processing on FOC current feedback in high-speed PMSM drive
PublikacjaIn applications where size and weight of the electric motor are among major design concerns, Permanent Magnet Synchronous Motors (PMSMs) with wide operational speed-range are commonly preferred. Due to limited inverter switching frequency, high-speed operation of a drive results in a low ratio between the switching frequency and the fundamental frequency of motor voltage. Such operating conditions have been recently identified...
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Effect of pine impregnation and feed speed on sound level and cutting power in wood sawing
PublikacjaThe sound levels along with the cutting power registered during the sawing process of the impregnated and non-impregnated pine wood at two feed speeds are shown and compared in this paper. Statistically significant differences in the acoustic signals occurred at the lower feed rate. The differences became smaller with an increase in the feed speed. In contrast to the sound signal, the differences...
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Speed Observer Structure of Induction Machine Based on Sliding Super-Twisting and Backstepping Techniques
PublikacjaThis paper presents an analysis of the two speed observer structures which are based on the backstepping and sliding super twisting approach. The observer stabilizing functions result from the Lyapunov theorem. To obtain the observer tuning gains the observer structure is linearized near the equilibrium point. The rotor angular speed is obtained from non-adaptive dependence. In the sensorless control system structure the classical...
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Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress
PublikacjaThe modern wood converting processes consists of several stages and material drying belongs to the most influencing future performances of products. The procedure of drying wood is usually realized between subsequent sawing operations, affecting significantly cutting conditions and general properties of material. An alternative methodology for determination of mechanical properties (fracture toughness and shear yield stress) based...
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Non-Adaptive Rotor Speed Estimation of Induction Machine in an Adaptive Full-Order Observer
PublikacjaIn the sensorless control system of an induction machine, the rotor speed value is not measured but reconstructed by an observer structure. The rotor speed value can be reconstructed by the classical adaptive law with the integrator. The second approach, which is the main contribution of this paper, is the non-adaptive structure without an integrator. The proposed method of the rotor speed reconstruction is based on an algebraic...
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Experimental comparison of the transition speed of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublikacjaA journal bearing test bench is used to find the transition speed between the hydrodynamic and mixed lubrication regimes for a modified magnetorheological (MR) fluid. It is shown that the transition speed of the bearing can be reduced by applying a local magnetic field near minimum film when it is lubricated with the MR fluid, and that this will only marginally increase friction. The lubricating performance of the MR fluid is compared...
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The Experimental Determination of Bearings Dynamic Coefficients in a Wide Range of Rotational Speeds, Taking into Account the Resonance and Hydrodynamic Instability
PublikacjaMethods for the experimental determination of dynamic coefficients are commonly used for the analysis of various types of bearings, including hydrodynamic, aerodynamic and foil bearings. There are currently several algorithms that allow estimating bearing dynamic coefficients. Such algorithms usually use various excitation techniques applied to rotor–bearings systems. So far only a small number of scientific publications show how...
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Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublikacjaThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
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The impact of drying and steaming processes on surface color changes of tension ad normal beech wood
PublikacjaThe aim of the article is to present the influence of high temperature to selected properties of beech wood (Fagus sylvatica L.). The properties such as moisture content, color changes and longitudinal warping were analyzed. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative alterations...
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Relationship between Fatigue Condition of Asphalt Pavements and Deflection Lag from Traffic Speed Deflectometer
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Evaluating structural characteristics of asphalt pavements by using deflection slopes from traffic speed deflectometer
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Vessel Scheduling Optimization Model Based on Variable Speed in a Seaport with One-Way Navigation Channel
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Measurement of idlers rotation speed in belt conveyors based on image data analysis for diagnostic purposes
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Studying the Influence of the Impact Gap Value on the Average Translational Speed of the Wheeled Vibration-Driven Robot
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RNS reverse high-speed converter with quasi-regular structure based on the Chinese Remainder Theorem
PublikacjaPrzedstawiono dwie nowe architektury szybkiego konwertera z systemuresztowego do systemu binarnego oparte o chińskie tw. o resztach. Zastosowano nowe struktury 4-operandowych sumatorów modulo 2M. Pierwsza ze struktur oparta jest o wstępne sumowanie najstarszych bitów wektorów sumy i przeniesienia na wyjściu sumatora CSA, natomiast druga o bezpośrednie wykrywanie przekroczenia 2M. Konwerter wykorzystujący drugą ze struktur charakteryzuje...
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Reduction of vibration level by the spindle speed optimisation during ball end milling of flexible details
PublikacjaPraca dotyczy nadzorowania drgań podczas skrawania przedmiotów podatnych frezem kulistym. Przedsatwiono wspomaganą komputerowo procedurę nadzorowania z optymalizacją prędkości obrotowej narzędzia. Przy modelowaniu wykorzystano niestacjonarny model obliczeniowy. Rezultatem modelowania jest układ hybrydowy, w którym oddzielono podukłady: modalny, łączący i strukturalny. Metoda wymaga identyfikacji częstości własnych co może być wykonane...
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Research of new two-speed planet type gear hydraulic motors with axial clearance compensation.
PublikacjaOpisano sposoby realizacji napędu dwubiegowego na przykładzie silnika satelitowego HS 3,2 [dm3/obr.] oraz przedstawiono zalety i przykłady zastosowań napędów wielobiegowych. Zaprezentowano porównanie metody analitycznej oraz eksperymentalnej wyznaczania nierównomierności chłonności hydraulicznego silnika satelitowego w celu zweryfikowania własności eksploatacyjnych silnika dwubiegowego HS 3,2/0,8 [dm3/obr] wyprodukowanego przez...
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High-Speed Binary-to-Residue Converter Design Using 2-Bit Segmentation of the Input Word
PublikacjaIn this paper a new approach to the design of the high-speed binary-to-residue converter is proposed that allows the attaining of high pipelining rates by eliminating memories used in modulo m generators. The converter algorithm uses segmentation of the input binary word into 2-bit segments. The use and effects of the input word segmentation for the synthesis of converters for five-bit moduli are presented. For the number represented...
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Speed, Alcohol and Safety Belts as Important Factors Influencing the Number of Fatalities in Road Accidents in the Voivodships
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A novel method for vibration surveillance during high speed ball end milling of flexible details
PublikacjaPraca dotyczy nadzorowania drgań podczas obróbki zakrzywionych przedmiotów podatnych frezem kulistym, z uwzględnieniem zgodności parametrów modelu modalnego. Przedstawiono analizę dynamiki niestacjonarnego okładu drgającego, z którego wydzielono podukład modalny, strukturalny i łączący. Zastosowano minimalizację poziomu drgań z dopasowaniem prędkości obrotowej wrzeciona do optymalnego kąta przesunięcia fazowego. Eksperymenty doświadczalne...
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A novel method for vibration surveillance during high speed ball end milling of flexible details
PublikacjaPraca dotyczy nadzorowania drgań układów niestacjonarnych modelowanych metodą elementów skończonych. Obróbka frezem kulistym przedmiotów podatnych jest często stosowana w przypadku nowoczesnych centrów obróbkowych. Drgania względne narzędzie-przedmiot obrabiany mogą doprowadzić do utraty stabilności i powstania drgań samowzbudnych typu chatter. W pracy proponuje się metodę minimalizacji poziomu drgań poprzez dopasowanie prędkości...
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The Optimal Spindle Speed Map for Reduction of Chatter Vibration During Milling of Bow Thruster Blade
PublikacjaW artykule przedstwiono przykład wykorzystania procedury tworzenia mapy optymalnych prędkosci obrotowych w celu ograniczenia drgań samowzbudnych podczas frezowania płata śruby okrętowego steru strumieniowego.
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Evolutionary sets of safe ship trajectories with speed reduction manoeuvres within traffic separation schemes
PublikacjaIn the previous paper the author presented the evolutionary ship trajectory planning method designed to support Traffic Separation Schemes (TSS). This time the extensions of this method are described which allow to combine evolutionary trajectory planning with speed reduction manoeuvres. On TSS regions with higher than usual density of traffic and smaller distances between ships, the course alterations alone are not always sufficient...
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Optimal spindle speed determination for vibration reduction during ball-end milling of flexible details
PublikacjaIn the paper a method of optimal spindle speed determination for vibration reduction during ball-end milling of flexible details is proposed. In order to reduce vibration level, an original procedure of the spindle speed optimisation, based on the Liao–Young criterion, is suggested. As the result, an optimal, constant spindle speed value is determined. For this purpose, on-stationary computational model of machining process is...
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Metrological analysis of an computerized system of protection against electric shock in circuits with variable speed drives
PublikacjaDrive systems, that can be operated at variable speed, are equipped with power electronics converters. This causes distortion of the earth current, and consequently the need to take into account the use of proper protective devices in relation to earth current harmonics. This paper presents a system for protection against electric shock in circuits with power electronics converters and metrological analysis indicating the requirements...
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The system combined of low-speed marine diesel engine and steam turbine in ship propulsion applications
PublikacjaPrzedstawiono koncepcje okrętowego układu kombinowanego silnik wolnoobrotowy tłokowy- turbina parowa, wykorzystującego ciepło zawarte w spalinach wylotowych.Porównano układ kombinowany dużej mocy dla dwóch silników tłokowych porównywalnych mocy z punktu widzenia termodynamicznego.
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Implementation of high-speed data transmission technological demonstrator using software defined radio technology
PublikacjaIn the article implementation of high-speed data transmission technological demonstrator using software defined radio technology is presented. A system architecture design including asymmetric framing transmission organization, which differs from the ones used in cellular systems is described. The construction of technological demonstrator consisting of management unit, radio unit and programmable multithreaded software performing...
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Implementation of high-speed data transmission technological demonstrator using software defined radio technology
PublikacjaIn the article implementation of a high-speed data transmission technological demonstrator using software defined radio technology is presented. A system architecture design including asymmetric framing transmission organization, which differs from the ones used in cellular systems is described. The construction of technological demonstrator consisting of a management unit, radio unit and programmable multi-threaded software performing...
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Considerations about the applicability of the Reynolds equation for analyzing high-speed near field levitation phenomena
Publikacjaequation for analyzing near field levitation (NFL) phenomena. Two separate approaches were developed, experimentally verified, and applied to meet the research objective. One was based on the Reynolds equation and the other was based on general conservation equations for fluid flow solved using computational fluid dynamic (CFD). Comparing the calculation results revealed that, for certain operating conditions, differences in the...
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Deformation and Surface Color Changes of Beech and Oak Wood Lamellas Resulting from the Drying Process
PublikacjaThe drying process was examined relative to parameters’ influence on the deformation and surface layer color changes of beech wood (Fagus sylvatica L.) and oak wood (Quercus robur L.). The goal was to analyze the impact of drying process conditions, wood and growth rings types, and load on the deformation and surface color changes of drying thin wooden elements. A further aim was to reduce the time of the lamella drying and minimize...
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Non-Adaptive Speed and Position Estimation of Doubly-Fed Induction Generator in Grid-Connected Operations
PublikacjaThe nonadaptive speed and position estimation scheme for a doubly-fed induction generator (DFIG) is presented in this article. The observer structure is based on the extension of the mathematical model of DFIG to the introduced H vector. Based on the defined H vector, the nonadaptive position and speed estimation is proposed. The Lyapunov method is extended to the practical stability theorem to stabilize the structure. The classic...
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Augmented speed control scheme of dual induction motors with mutual flux angle control loop
PublikacjaThis paper proposes an augmented speed control scheme of dual induction motors fed by a five-leg voltage source inverter (VSI) with a common/shared-leg. An additional control loop is proposed here and based on the mutual flux angle – the difference between flux angular positions of the IMs. The main purpose of this research is to minimize the energy losses in the common inverter leg by controlling the mutual flux angle, at equal...
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Bifurcation of equilibrium forms of a gas column rotating with constant speed around its axis of symmetry
PublikacjaWe will be concerned with the problem of deformation of the lateral surface of a column that rotates with constant speed around its axis of symmetry. The column is filled by a gas and our goal is to investigate the deformation of the lateral surface depending on the pressure of the gas.
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MRAS-Based Switching Linear Feedback Strategy for Sensorless Speed Control of Induction Motor Drives
PublikacjaThis paper presents a newly designed switching linear feedback structure of sliding mode control (SLF-SMC) plugged with an model reference adaptive system (MRAS) based sensorless fieldoriented control (SFOC) for induction motor (IM). Indeed, the performance of the MRAS depends mainly on the operating point and the parametric variation of the IM. Hence, the sliding mode control (SMC) could be considered a good control alternative...
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Speed estimation of a car at impact with a W-beam guardrail using numerical simulations and machine learning
PublikacjaThis paper aimed at developing a new method of estimating the impact speed of a passenger car at the moment of a crash into a W-beam road safety barrier. The determination of such a speed based on the accident outcomes is demanding, because often there is no access to full accident data. However, accurate determination of the impact speed is one of the key elements in the reconstruction of road accidents. A machine learning algorithm...
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Accidents, victims and risk levels on regional roads in pomorskie voivodeship, 2017-2019 - Excessive speed accidents
Dane BadawczeData contain risk classification on regional roads (voivodeship roads) in pomorskie voivodeship in 2017-2019, cause of accidents: Excessive speed accidents. Measures used to assess the level of risk are (5 classes low, low to medium, medium, medium to high, high):
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Appliance of High Speed Camera during Industrial Exploitation on the Example of Static and Dynamic Tests of Steel Probes
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Hydroacoustic System in a Biomimetic Underwater Vehicle to Avoid Collision with Vessels with Low-Speed Propellers in a Controlled Environment
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Research of low-speed high torque planet motors supplied with oil-in-water emulsion as working liquid.
PublikacjaWiększość hydraulicznych układów napędowych obecnie jest zasilanych olejami. Ale olej jako medium robocze nie może być stosowany wszędzie tam, gdzie istnieje ryzyko pożaru. dlatego też są stosowane trudnopalne i niepalne ciecze hydrauliczne ja: emulsje, mikroemulsje i roztwory. W referacie opisano stanowisko badawcze zaprojektowane i zbudowane w Katedrze Hydrauliki i Pneumatyki PG, przedstawiono wyniki badań hydraulicznego silnika...
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The Use of Different Modes of Post-Activation Potentiation (PAP) for Enhancing Speed of the Slide-Step in Basketball Players
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Examining Impact of Speed Recommendation Algorithm Operating in Autonomous Road Signs on Minimum Distance between Vehicles
PublikacjaAn approach to a new kind of recommendation system design that suggests safe speed on the road is presented. Real data obtained on roads were used for the simulations. As part of a project related to autonomous road sign development, a number of measurements were carried out on both local roads and expressways. A speed recommendation model was created based on gathered traffic data employing the traffic simulator. Depending on...
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Sensorless Control of Induction Motor Based on Super-Twisting Sliding Mode Observer With Speed Convergence Improvement
PublikacjaThe super twisting sliding-mode observer (ST-SMO) has been proposed to achieve an effective method for alleviating low-order harmonics of measured quantities, issues related to DC drift, and suppression of chattering due to low-frequency sampling. The conventional ST-SMO, on the other hand, suffers from control delay in the convergence trajectory due to the system disturbance, resulting in decreased anti-disturbance capability...
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Mathematical Models of Control Systems of Angular Speed of Steam Turbines for Diagnostic Tests of Automatic and Mechatronic Devices
PublikacjaAccurate modeling of physical processes of many automatics and mechatronics systems is often necessity. In power system such a process is control of angular velocity of power objects during connection to operation in parallel. This process is extremely dynamic. For this reason response of control system depends from changes of many physical parameters (temperature, pressure and flow of the medium, etc.). Precision modeling influences...
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Speed sensorless ac drive with inverter output filter and fault detection using load torque signal
PublikacjaIn this paper, a sensorless induction motor (IM) drive using speed observer system is presented. The system includes load torque computation for gear fault detection. Nonlinear control method is adopted for controlling the motor over a wide speed range. An LC filter for smoothing current and voltage waveforms is used at the output of the voltage inverter. The use of filter imposes more building of the used observer to avoid using...
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Study of prototype multi-pole non-salient field winding for high speed brushless synchronous generator
PublikacjaIn this paper a non-salient field winding for a brushless synchronous generator working with high speed in an autonomous energy generation system (e.g. airplane power grid) has been presented. A conception of a six-pole cylindrical-rotor with distributed field winding has been proposed. Comparison study of salient and prototype non-salient field winding has been carried out. Chosen simulation and measurement results of the generator...