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Wyniki wyszukiwania dla: modelling, its, vehicle speed
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Acoustic journal bearing – Performance under various load and speed conditions speed conditions
PublikacjaThe paper presents results of experimental testing aiming at finding out what effect system of piezo-electric actuators (PZTs)attached to an aerodynamic journal bearing has on the magnitude of shaft's motion within the bearing operating at specified speed and load. The results clearly demonstrate effectiveness of PZTs in mitigating the shaft's motion thus contributing to the increased stability of the bearing. This stabilizing...
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CFD and FEM model of an underwater vehicle propeller
PublikacjaDuring the project execution of design and optimization the Remotely Operated Vehicle (ROV) research on its propulsion has been carried out. The entire project was supported by CFD and FEM calculations, which taking into account the characteristics of underwater vehicle. One of the tasks was to optimize the semi-open duct for horizontal propellers, which provided propulsion and controllability in horizontal plane. In order to...
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Clonal selection algorithm for vehicle routing
PublikacjaOver the years several successful computing techniques have been inspired by biological mechanisms. Studies of the mechanisms that allow the immune systems of vertebratesto adapt and learn have resulted in a class of algorithms called artificial immune systems. Clonal selection is a process that allows lymphocytes to launch a quick response to known pathogens and to adapt to new, previously unencountered ones. This paper presents...
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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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STUDY ON THE RELATIONSHIP BETWEEN VEHICLE MAINTENANCE AND FUEL CONSUMPTION
PublikacjaA contemporary road vehicle (RV) is a rather complex system, consisting of a large number of subsystems, assemblies, units, and elements (parts). While operating, an RV interacts with the environment, and its elements interact with each other. Consequently, the properties (parameters) of these elements change in the process - hardness, roughness, size, relative position, gapping, etc. A partial solution to the presented problems...
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A Triplet-Learnt Coarse-to-Fine Reranking for Vehicle Re-identification
PublikacjaVehicle re-identification refers to the task of matching the same query vehicle across non-overlapping cameras and diverse viewpoints. Research interest on the field emerged with intelligent transportation systems and the necessity for public security maintenance. Compared to person, vehicle re-identification is more intricate, facing the challenges of lower intra-class and higher inter-class similarities. Motivated by deep...
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Investigations on the the dynamics of motor vehicle driving in nighttime conditions
PublikacjaThe article describes investigations on vehicle driving in nighttime conditions
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THE MODELLING OF ACCUMULATION AND DISSIPATION OF ENERGY IN MECHANICAL DRIVE SYSTEM
PublikacjaThis paper presents a modelling of accumulation and dissipation energy in simple drive system. The simple drive system is presented by laboratory stand designed for calculate fatigue life of material for bending and rotation tests pieces. The laboratory stand was prepared to diagnosis of fatigue life of material by use energetic methods. This idea was submitted as utility model to Polish Patent Office. This laboratory stand gives...
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Speed observer of induction machine based on backstepping and sliding mode for low‐speed operation
PublikacjaThis paper presents a speed observer design based on backstepping and slidingmode approaches. The inputs to the observer are the stator current and thevoltage vector components. This observer structure is extended to the integra-tors. The observer stabilizing functions contain the appropriate sliding surfaceswhich result from the Lyapunov function. The rotor angular speed is obtainedfrom the non‐adaptive formula with a sliding...
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Critical Review on Robust Speed Control Techniques for Permanent Magnet Synchronous Motor (PMSM) Speed Regulation
PublikacjaThe permanent magnet synchronous motor (PMSM) is a highly efficient energy saving machine. Due to its simple structural characteristics, good heat radiation capability, and high efficiency, PMSMs are gradually replacing AC induction motors in many industrial applications. The PMSM has a nonlinear system and lies on parameters that differ over time with complex high-class dynamics. To achieve the excessive performance operation...
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Challenges associated with the design of a small unmanned autonomous maritime vehicle
PublikacjaThe paper contains the preliminary results of the research connected with development of a small unmanned autonomous maritime vehicle. First of all a general description of research is introduced. Next, a concept of a vehicle is presented. Then, a brief description of a research method is given. Next, the current research problems under way are introduced. They concern the ballasting, motion and precise position stabilization system...
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Assessing Highway Travel Time Reliability using Probe Vehicle Data
PublikacjaProbe vehicle data (also known as “floating car data”) can be used to analyze travel time reliability of an existing road corridor in order to determine where, when, and how often traffic congestion occurs at particular road segments. The aim of the study is to find the best reliability performance measures for assessing congestion frequency and severity based on probe data. Pilot surveys conducted on A2 motorway in Poland confirm...
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Modelling of Geared Multi-Rotor System
PublikacjaIn the paper the method of modelling a speed-varying geared rotor system is presented. The proposed approach enables us to obtain an accurate low-order lumped parameter representation of the investigated system. The final model consists of reduced modal models of an undamped beam/torsional shaft system as well as a spatially lumped model of other linear and nonlinear phenomena including gear mesh interaction.
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Very high altitude micro air vehicle deployment method
PublikacjaThe paper presents the original work and method for high altitude micro air vehicle deployment. The method is based on the scientific ballooning, and adapted for stratospheric flight of commercial off-the-shelf micro air vehicle in flying wing configuration. The High Altitude Micro Air Vehicle, built for this research, was deployed during a test experiment at the lower level of the stratosphere. The results of the experiment and...
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Method of estimating the rolling resistance coefficient of vehicle tyre using the roller dynamometer
PublikacjaThe tendency in the past few years has been to introduce tyres with lower rolling resistance coefficients to the market. This paper presents a mathematical method for determining the rolling resistance coefficients variation depending on the speed. The method uses power balance which results from automobile dynamics while rolling on chassis dynamometer. The rolling resistance coefficients of tyres obtained through ‘drum test method’,...
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Four-state stochastic model of changes in the reliability states of a motor vehicle
PublikacjaThe properties of semi-Markov processes have been generally characterized and the applicability of the theory of such processes to the determining of the reliability of motor cars and other road vehicles has been explained. A formal description of the process of changes in the motor vehicle technical states considered as reliability states and a model of this process in the form of a one-dimensional stochastic process have been...
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Stabilization Method for Speed Observer of Induction Machine
PublikacjaThis article proposes the speed estimation principles dedicated to the observer structures based on the machine mathematical model. The rotor speed is reconstructed based on the mathematical model of a machine by using both adaptive and nonadaptive schemes. The presented principle is generalized to the classical nonlinear system in the vector form and can be applied to induction machines. The proposed rotor speed reconstruction...
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Modeling of performance of a AUV vehicle towards limiting the hydro-acoustic field.
PublikacjaSome results of research devoted to the modeling of a AUV-Stealth vehicle performance towards limiting its hydro-acoustic field are presented in the paper. At the beginning the AUV-Stealth autonomous underwater vehicle concept is described. Then the method of research is introduced. Next the key design drivers of the AUV-Stealth vehicle are presented. Between them are the AUV-Stealth hull form, arrangement of internal spaces,...
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Design of Resilient Vehicle-to-Infrastructure Systems
PublikacjaVehicular ad hoc networks (VANETs) have recently gained noticeable attention due to advantages in improving road traffic safety, shaping the road traffic and providing infotainment opportunities to travellers. However, transmission characteristics following from the IEEE 802.11p standard and the high mobility of VANET nodes remarkably reduce the lifetime, reach and capacity of wireless links, and often lead to simultaneous disruptions...
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Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
PublikacjaDue to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate...
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EVALUATING THE EFFECTIVENESS OF NON-PHYSICAL SPEED MANAGEMENT MEASURES
PublikacjaThe subject of the Authors' analyses is a group of non-physical speed management measures. How effective they are depends primarily on how willing drivers are to accept restrictions. Social and cultural factors play a major role. The effectiveness of these measures is not clear and requires further research. The authors conducted such research and evaluated the effects of nonphysical speed management measures on driver behaviour...
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COMPARISON OF NOISE EMISSION OF HCT AND CLASSIC VEHICLE COMBINATIONS FOR TIMBER TRANSPORTATION IN SWEDEN
PublikacjaBy means of a special simulation tool, the noise emission of a high-capacity heavy vehicle (11 axles) was compared to that of a classic heavy vehicle (a truck-dolly-semitrailer with 8 axles). The two cases are designated “Extended vehicle” versus “Classic vehicle” in this study, having total lengths of 34 and 25 m, respectively. The Classic vehicle represents the most common articulated heavy vehicle configuration for transport...
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An Intergrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle
PublikacjaIn the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces....
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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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Data-driven, probabilistic model for attainable speed for ships approaching Gdańsk harbour
PublikacjaThe growing demand for maritime transportation leads to increased traffic in ports. From this arises the need to observe the consequences of the specific speed ships reach when approaching seaports. However, usually the analyzed cases refer only to the statistical evaluation of the studied phenomenon or to the empirical modelling, ignoring the mutual influence of variables such as ship type, length or weather conditions. In this...
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Speed dependency of temperature effects on road traffic noise
PublikacjaRecently, a new literature review on the influence of temperature on tire/road noise became available, based on a compilation of large amounts of data from empirical research. This review showed that the effect of temperature is roughly double of that previously assumed and taken account of in international standards. This makes temperature one of the main sources of error in measurement results. Furthermore, it suggested that...
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Separability Assessment of Selected Types of Vehicle-Associated Noise
PublikacjaMusic Information Retrieval (MIR) area as well as development of speech and environmental information recognition techniques brought various tools in-tended for recognizing low-level features of acoustic signals based on a set of calculated parameters. In this study, the MIRtoolbox MATLAB tool, designed for music parameter extraction, is used to obtain a vector of parameters to check whether they are suitable for separation of...
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Traffic Noise Analysis Applied to Automatic Vehicle Counting and Classification
PublikacjaProblems related to determining traffic noise characteristics are discussed in the context of automatic dynamic noise analysis based on noise level measurements and traffic prediction models. The obtained analytical results provide the second goal of the study, namely automatic vehicle counting and classification. Several traffic prediction models are presented and compared to the results of in-situ noise level measurements. Synchronized...
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Analysis of the process of water entry of an amphibious vehicle
PublikacjaThe paper presents a method of computational and experimental analysis of the process of water entry of an amphibious vehicle. The computational method is based on the Reynolds Averaged Navier-Stokes Equations (RANSE) solver and the xperiment was carried out in the towing tank at Ship Design and Research Centre S.A. with the use of a scale model. The analysis was focused on the safety of water entry, i.e. the maximum pitch and...
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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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Toward Intelligent Vehicle Intrusion Detection Using the Neural Knowledge DNA
PublikacjaIn this paper, we propose a novel intrusion detection approach using past driving experience and the neural knowledge DNA for in-vehicle information system security. The neural knowledge DNA is a novel knowledge representation method designed to support discovering, storing, reusing, improving, and sharing knowledge among machines and computing systems. We examine our approach for classifying malicious vehicle control commands...
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Modeling the impact of discretizing rotor angular position on computation of field-oriented current components in high speed electric drives
PublikacjaModern drives consist of alternating current electric motors, and the field-oriented control (FOC) of such motors enables fast, precise, and robust regulation of a drive's mechanical variables such as torque, speed, and position. The control algorithm, implemented in a microprocessor, requires feedback from motor currents, and the quality of this feedback is essential to a drive's control properties. Motor phase currents are sampled...
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Autonomous Control of the Underwater Remotely Operated Vehicle in Collision Situation with Stationary Obstacle
PublikacjaThe article considers the problem of autonomous control of the underwater remotely operated vehicle mini Remotely Operated Vehicle (ROV) in a collision situation with a stationary obstacle. The control of the collision avoidance process is presented as a synthesis of fuzzy proportional-differential controllers for the control of distance and orientation concerning the detected stationary obstacle. The control of the submergence...
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Risk Assessment at Unsignalized Intersections Based on Human-Road-Environment-Vehicle System Applying Fuzzy Logic
PublikacjaThe constant increase in motorization level and traffic density increases risks due to dangerous situations for road participants. Therefore, assessing the accident level of road network elements has been an urgent task over the past decades. However, existing approaches mainly rely on traffic flow parameters and account for dynamic vehicle characteristics. The research aims to design a model accounting for uncertain factors (weather...
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Evaluation of the energy efficiency of electric vehicle drivetrains under urban operating conditions
PublikacjaIn electric vehicles, as in hybrids vehicles, a very important factor affecting the energy efficiency of the powertrain is the ability to use the regenerative braking energy. Depending on the settings available in electric vehicles, the driver can choose different modes of operation: switch off the regenerative braking mode altogether, select the intensity of regenerative braking, or leave the control system in automatic mode....
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Analytical modeling of electric drives for vehicle traction control systems
PublikacjaWheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five...
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Autonomous Vehicle Navigation in Dense Urban Area in Global Positioning Context
PublikacjaAutonoumous vehicle services are likely to be adopted in dense urban area. Some research prove that autonomous transport might be capable of improving the transport needs of few times and as a consequence sustainability, congestion and safety may be improved. The world, hopefully is close to a transport revolution age. These studies are perhaps exaggerated, over-optimistic and far fro fully operational. The paper takes into account...
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Dynamic effect of the vehicle passing under lightweight footbridge.
PublikacjaThe paper describes a numerical study of dynamic response of cable-stayed steel footbridge for a big lorry passing underneath. The footbridge is an existing object crossing Wolska street in Warsaw. The structural model of footbridge was verified by dynamic test loading. A numerical study of a vehicle passing under footbridge is presented. 2D and 3D incompressible flow fields are modeled using sliding mesh in transient CFD computation....
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Electric shock hazard in circuits with variable-speed drives
PublikacjaThe conventional approach to electrical safety under fault condition in typical power systems considers earth fault currents of sinusoidal waveform and frequency of 50/60 Hz. However, in circuits with variable-speed drives, there is earth fault current flow with harmonics, and these harmonics influence the threshold of ventricular fibrillation. The paper presents earth fault current waveforms in circuits with variable-speed drives...
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The effects of vehicle restraint systems on road safety
PublikacjaKey to understanding the needs and tools of road infrastructure management for preventing run-off-road crashes or minimising their consequences, is to identify the hazads and sources of hazards caused by wrong or improper use of road safety devices and identify errors in the desifn, structure, construction and operation of road safety devices. Studying such an extended scope of the problem required fieldwork and surveys with road...
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Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework
PublikacjaIntegrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In...
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Control design for slow speed positioning
PublikacjaThe problem under study is a synthesis of position and heading control system for low frequency model of surface vessel described by 3 DOF mathematical model. The recursive vectorial backstepping control design was used to keep fixed position and heading in presence of wave disturbances. The controller has been simulated on computer model of scaled supply vessel. It has been assumed that the actuators produce generalized forces...
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Unidirectional DC/DC Converter with Voltage Inverter for Fast Charging of Electric Vehicle Batteries
PublikacjaThe paper proposes the adaptation of the industrial plant’s power network to supply electric vehicle (EV) fast-charging converters (above 300 kW) using renewable energy sources (RESs). A 600 V DC microgrid was used to supply energy from RESs for the needs of variable speed motor drives and charging of EV batteries. It has been shown that it is possible to support the supply of drive voltage frequency converters (VFCs) and charging...
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Vehicle detector training with minimal supervision
PublikacjaRecently many efficient object detectors based on convolutional neural networks (CNN) have been developed and they achieved impressive performance on many computer vision tasks. However, in order to achieve practical results, CNNs require really large annotated datasets for training. While many such databases are available, many of them can only be used for research purposes. Also some problems exist where such datasets are not...
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Speed management on local government managed roads – research, recommendations and guidelines
PublikacjaCommissioned by the National Road Safety Council Secretariat, the project “Guidelines for speed management on local government managed roads” studied car driver be haviour when subjected to selected speed management measures such a local speed restrictions, surveillance, traffic calming and restricted speed areas. In addition, analyses were conducted on the impact of selected me asures...
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A commercial of the shelf components for a unmanned air vehicle photogrammetry
PublikacjaA photogrammetry from a unmanned aerial vehicle (UAV) can be understood as a new measurement tool. Is introduces a low-cost alternatives for a traditional aerial photogrammetry. A commercial off-the-shelf products (COTS), that are commercially available for a costumers, are the standard manufactures products, not custom. COTS products are available in the commercial market and can be bought and used under government contract. That...
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Kinetic analysis of the stage for a high speed steam turbine
PublikacjaThis article analyzes possibilites of resonances within a control stage for a high speed steam turbine. This stage hase been based on assembling of a single blade to a rotating disk and increasing of rigidity of the system by using of a bandage. In the analysis will be nd a possiblity of resonance frequency, and mistuning by showing safety working ranges. The calculations have bean used the3D modal and harmonic analysis by the...
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Estimation of Vehicle Energy Consumption at Intersections Using Microscopic Traffic Models
PublikacjaThis paper addresses issues related to modeling energy consumption and emissions using microscopic traffic simulations. This paper develops a method in which a traffic model is used to calculate the energy needed to travel through selected types of intersections. This paper focuses on energy consumption and derived values of calculated energy, which can be, for example, carbon dioxide emissions. The authors present a review of...
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A VISION-BASED UNMANNED AERIAL VEHICLE NAVIGATION METHOD
PublikacjaThe satellite navigation systems are the main position sources for unmanned aerial vehicles (UAVs). This fact limits the area of UAVs operation to the places where radio signals is visible for a satellite navigation system receiver, mounted on the vehicle-outdoor navigation. Closed spaced are unavailable for vehicles which navigation is based on global satellite navigation systems (GNSS). Miniature UAV (MiniUAV) is able to operate...
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Induction motor control application in high-speed train electric drive
PublikacjaThe chapter presents an application of induction motor mechanical speed and load torque observers in high-speed train drives. The observers are applied for a 1.2-MW electric drive with an induction motor. The goal of using such observers is to utilize computed variables for diagnostic purposes of speed sensors and torque transmission system. The concept of diagnostic system is presented in this paper, and proper criteria are proposed....