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Acta polytechnica HungaricaVolume 7, Issue No. 1 (2010.)


  • Mária ©vecová ,
    Duąan Kocur :

    Abstract: Target tracking using time of arrival measurements belongs to the primary tasks solved within radar signal processing. In this paper, the Taylor series-based tracking algorithm that uses time of arrival measurements for through wall tracking of the moving target is introduced. The proposed algorithm is derived from the Taylor series method applied for target localization. In contrast to the Taylor series method, the Taylor seriesbased tracking algorithm exploits for target positioning not only actual time of arrival measurements, but also the target position estimated in the previous time instant. In order to improve the tracking ability of the proposed algorithm, a suitable weighting of the input data of the algorithm is applied. The performance of the Taylor series-based tracking algorithm will be compared with the performance of the direct calculation method and linear Kalman filtering. For that purpose, two real scenarios of through wall tracking of a moving person will be analysed. The obtained results will show very clearly that the new Taylor series based tracking algorithm introduced in this paper can provide the better estimate of the target trajectory than the other tested localization and tracking algorithms.

    Keywords: localization, target tracking, Taylor series, TOA, UWB radar system

  • Tiberiu Tudorache ,
    Liviu Kreindler :
    Design of a Solar Tracker System for PV Power Plants23-39en [1.26 MB - PDF]EPA-02461-00022-0020

    Abstract: This paper deals with the design and execution of a solar tracker system dedicated to the PV conversion panels. The proposed single axis solar tracker device ensures the optimization of the conversion of solar energy into electricity by properly orienting the PV panel in accordance with the real position of the sun. The operation of the experimental model of the device is based on a DC motor intelligently controlled by a dedicated drive unit that moves a mini PV panel according to the signals received from two simple but efficient light sensors. The performance and characteristics of the solar tracker are experimentally analyzed.

    Keywords: Solar tracker system, design and execution, experimental investigations

  • Ján Labun ,
    Frantiąek Adamčík ,
    Ján Piµa ,
    Ladislav Madarász :

    Abstract: Radio altimeters are based on the principle of radio location of the earth’s surface using a frequency-modulated standing wave. The relatively simple method of measurement consists in the evaluation of the number of pulses generated as resulting from the mixing of the transmitted and received signals. Such a change in the number of modulated pulses within a certain altitude interval, however, is not so simple and is a determinant issue in defining the precision of the radio altimeter. Being knowledgeable of this law in a wider context enables us to enter into discussion on the possibilities of further increasing the precision of measuring low altitudes. The article deals with the law underlying the change in the number of radio altimeter pulses with the changing altitude measured.

    Keywords: radio altimeter, precision of measuring altitude, frequency modulation, the law of pulse number changes, critical altitude, methodical error

  • Siavash Sadeghi ,
    Mojtaba Mirsalim ,
    Arash Hassanpour Isfahani :

    Abstract: Dynamic behavior analysis of electric motors is required in order to accurately evaluate the performance, energy consumption and pollution level of hybrid electric vehicles. Simulation tools for hybrid electric vehicles are divided into steady state and dynamic models. Tools with steady-state models are useful for system-level analysis whereas tools that utilize dynamic models give in-depth information about the behavior of sublevel components. For the accurate prediction of hybrid electric vehicle performance, dynamic modeling of the motor and other components is necessary. Whereas the switched reluctance machine is well suited for electric and hybrid electric vehicles, due to the simple and rugged construction, low cost, and ability to operate over a wide speed range at constant power, in this paper dynamic performance of the switched reluctance motor for e series hybrid electric vehicles is investigated. For this purpose a switched reluctance motor with its electrical drive is modeld and simulated first, and then the other components of a series hybrid electric vehicle, such as battery, generator, internal combusion engine, and gearbox, are designed and linked with the electric motor. Finally a typical series hybrid electric vehicle is simulated for different drive cycles. The extensive simulation results show the dynamic performance of SRM, battery, fuel consumption, and emissions.

    Keywords: Dynamic Modeling, Switched Reluctance Motor, Series Hybrid Electric Vehicle, ADVISOR, Vehicle Performance

  • Nobert Ádám :
    Single Input Operators of the DF KPI System73-86en [301.99 kB - PDF]EPA-02461-00022-0050

    Abstract: The DF-KPI system is a multiprocessor system based on the dynamic data flow computing model, where each dyiadic instruction requires dynamic matching of its operands. This process is associated with the processing units of the DF-KPI system. The processing units are designed as a dynamic multi-function pipelined unit with LOAD, FETCH, OPERATE, MATCHING and COPY segments. In this article, an architecture design at a logical level of the dynamic multi-function pipelined unit, which handles processing of operand matching for single input data flow operators is suggested.

    Keywords: data flow, operand matching, data flow graph, single input data flow operators

  • Sefer Kurnaz ,
    Omar Cetin :

    Abstract: Autonomous control of UAVs has become a popular research topic in recent years. This paper is concerned with the flight of UAVs (Unmanned Aerial Vehicles) and proposes fuzzy logic based autonomous flight and landing system controllers. Three fuzzy logic modules are developed under the main navigation control system and three more for the autonomous landing control system to control of the altitude, the speed, and the position against the runway, through which the global position (latitude-longitude) of the air vehicle is controlled. A SID (Standard Instrument Departure) and TACAN (Tactical Air Navigation) approach is used and the performance of the fuzzy-based controllers is evaluated with time based diagrams under MATLAB’s standard configuration and the Aerosim Aeronautical Simulation Block Set which provides a complete set of tools for rapid development of detailed 6 degree-of-freedom nonlinear generic manned/unmanned aerial vehicle models. The Aerosonde UAV model is used in the simulations in order to demonstrate the performance and the potential of the controllers. Additionally, some visual tools are deployed in order to get visual outputs that aid the designer in the evaluation of the controllers. Despite the simple design procedure, the simulated test flights indicate the capability of the approach in achieving the desired performance.

    Keywords: UAV, Fuzzy Logic Controller, Autonomous Flight Control, Autonomous Landing System

  • Ján ©terba ,
    Juraj Gazda ,
    Marc Deumal ,
    Duąan Kocur :

    Abstract: This paper presents a new algorithm for the nonlinear distortion cancellation and channel re-estimation in an iterative manner for the OFDM transmission systems. Whereas in practical OFDM systems, where nonlinear amplifiers are used in the transmitter, data as well as pilot symbols are nonlinearly distorted. As perfect channel state information is often assumed in many papers, the effect of the nonlinear distortion of the pilot symbols is usually not accounted for, and the data symbols are considered only. However, as the pilot symbols are used to obtain the channel state information, the distortion caused to pilot symbols by the nonlinear amplification is of the great importance, and for this reason this effect should be taken into account. To address this issue, in this paper, an efficient algorithm will be introduced for joint data recovery and channel re-estimation in an iterative manner for OFDM transmission system. This algorithm iteratively estimates the nonlinear distortion due to nonlinear high power amplifier of the transmitter and then it uses it to compensate for this nonlinear distortion of the data and the pilot symbols, which are subsequently used for subsequent and more precise channel re-estimation. As is shown in this paper, the proposed algorithm can be used to reduce nonlinear distortions even in situations when highly nonlinear amplifiers are applied.

    Keywords: OFDM, iterative receiver, channel re-estimaiton, PAPR, nonlinear distortion

  • Péter Várlaki ,
    Imre J. Rudas ,
    László T. Kóczy :

    Abstract: This paper deals with the historical origin of the primordial image of the fine structure constant (FSC) and the number 137 as the Self’s own number archetype, which plays a central role in the poetic-hermeneutic system of the Holy Crown of Hungary. We intend to show that the allegorical and symbolical images which are observed as the manifestation of unconscious and interpreted and analyzed in the Pauli-Jung collaboration have a lengthy synchronistic relationship with the “archetypal model” of the FSC found in the marvellous enamel pictures of St. Stephen’s Crown.

    Keywords: fine structure constant, number archetypes, hermeneutical systems, creative background process