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1

Analysis of micro-electromechanical inertial measurement units for unmanned aerial vehicle applications

Mammadov Aftandil

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 117

129--138

EN

Typically, an inertial navigation system (INS) is used to determine the position, speed, and orientation of an object moving relative to the earth's surface. The navigation information (position, speed and orientation) of an unmanned aerial vehicle (UAV) is needed to control its flight. Since the resistance of INS to interferences is very high, it is possible to ensure reliable flights in conditions of high-intensity noise. This article explores the principles of constructing inertial measurement units (IMU) that are part of the INS and indicates perspective directions for their development. Micro-electromechanical inertial measurement units were studied in this work, and functional and principal electrical circuits for connecting units of inertial measurements to the microcontroller were developed. The results of practical measurements of units without calibration and after calibration were obtained using the created laboratory device. Based on the obtained results, the necessity of sensor calibration was revealed, and accuracy was improved by performing calibration with the Kalman filter algorithm. The Kalman filter is the heart of the navigation system. In a low-cost system, IMU errors like bias, scale factor error and random walk noise dominate the INS error growth.

2

Wentylacja dachu stromego, czyli dach bez wilgoci

Szot Joanna

Izolacje

|

2022

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R 27, nr specjalny

64--65

PL

Tyle się mówi, że budynki powinny być szczelne. Budując więc dom, pilnujemy, aby nie było mostków termicznych, przez które uciekałoby ciepło. Zresztą słusznie. Wydawać by się mogło, że również dach nie powinien mieć żadnych szczelin. Okazuje się jednak, że wentylacja dachu jest koniecznością.

3

The Lower Limit of Pitch Perception for Pure Tones and Low-Frequency Complex Sounds

Jurado Carlos, Larrea Marcelo, Moore Brian C. J.

Archives of Acoustics

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2021

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Vol. 46, No. 3

459--469

EN

The lower limit of pitch (LLP) perception was explored for pure tones, sinusoidally amplitude-modulated (SAM) tones with a carrier frequency of 125 Hz, and trains of 125-Hz tone pips, using an adaptive procedure to estimate the lowest repetition rate for which a tonal/humming quality was heard. The LLP was similar for the three stimulus types, averaging 19 Hz. There were marked individual differences, which were correlated to some extent across stimulus types. The pure-tone stimuli contained a single resolved harmonic, whereas the SAM tones and tone-pip trains contained only unresolved components, whose frequencies did not necessarily form a harmonic series. The similarity of the LLP across stimulus types suggests that the LLP is determined by the repetition period of the sound for pure tones, and the envelope repetition period for complex stimuli. The results are consistent with the idea that the LLP is determined by a periodicity analysis in the auditory system, and that the longest time interval between waveform or envelope peaks for which this analysis can be performed is approximately 53 ms.

4

Determining of correlation relationship between roll, pitch, and yaw for UAVs

Hlotov Volodymyr, Hunina Alla, Yurkiv Mariana, Siejka Zbigniew

Reports on Geodesy and Geoinformatics

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2019

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Vol. 107

13--18

EN

Currently, UAVs are intensively being introduced into topographic-photogrammetric production for topographic digital aerial photography and laser scanning. These technologies have a number of advantages: they don’t require specially prepared platforms and launchers, they are relatively inexpensive unlike large aircrafts, and they are safe. However, there are still many unsolved problems for ultralight UAVs, especially when the aerial photography is made. As you know, the requirements for the implementation of the aerial survey process are quite stringent, first of all, for horizontal flight: the angles of inclination must be within 3–5 degrees, since exceeding these tolerances significantly affects the accuracy for determining the spatial coordinates of objects. Therefore, there was an idea to conduct researches of dependences between the pitch α, roll ω and yaw κ. For this purpose, 100 images obtained from aircraft-type UAV ‘Arrow’ developed and created by specialists from Lviv Polytechnic National University and ‘Abris’ were used. As a result of the study, the multiple correlation coefficient and the parameters of the linear regression equation for the angular elements of the exterior orientation of digital images were calculated. In addition, statistical quality evaluations for the obtained regression model were carried out. Analysis of the received data allows to assert that angular elements of exterior orientation are correlated with each other. Therefore, in the further imaging materials, processing it becomes possible to make compensation of this fact and to improve calculation accuracy of spatial coordinates of points.

5

The use of pitch in Large-Vocabulary Continuous Speech Recognition System

Płonkowski M., Urbanovich P.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 8

78--81

EN

In this article the authors normalize the speech signal based on the publicly available AN4 database. The authors added to the algorithm of calculating the MFCC coefficients, the normalization procedure, that uses pitch of the voice. As demonstrated by empirical tests authors were able to improve speech recognition accuracy rate of about 20%.

PL

W niniejszym artykule autorzy normalizują sygnał mowy wykorzystując publicznie dostępną bazę danych AN4. Autorzy dodali do algorytmu obliczania współczynników MFCC, procedurę normalizacji, wykorzystującą wysokość tonu głosu. Jak wynika z przeprowadzonych testów, autorzy uzyskali poprawę dokładności rozpoznawania mowy o około 20%.

6

Wykorzystanie techniki GPS do wyznaczenia kątów heading, pitch i roll. Cz. 1

Wierzbicki D., Krasuski K.

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2016

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Vol. 7, Nr 1 (23)

113--125

PL

W artykule przedstawiono eksperyment dotyczący wyznaczenia kątów heading, pitch i roll z wykorzystaniem technologii GPS. W tym celu stworzono autorski program HPR_GPS, którego kod źródłowy napisano w języku Scilab 5.4.1. Zaprezentowano zasadę działania aplikacji HPR_GPS oraz przedstawiono algorytm wyznaczenia kątów heading, pitch i roll. Dodatkowo, porównano otrzymane wyniki kątów z programu HPR_GPS ze źródłowymi danymi z INS. Średnia różnica dla kąta heading wynosi 0,29° z błędem średnim 5,96°, dla kąta pitch wynosi 4,98° z błędem średnim 1,62°, zaś dla kąta roll wynosi 0,06° z błędem średnim 2,31°.

EN

This article presents an experiment concerning the designation of heading, pitch and roll angles using GPS technology. For this purpose, authorial HPR_GPS software has been created, the code source of which was written in Scilab 5.4.1 language. Operation of application was presented and an algorithm of estimation of heading, pitch, and roll angles was showed. Additionally, final results of angles from HPR_GPS software were compared with raw INS data. Based on comparison, mean difference for heading angle is equal to 0.29° with standard deviation of 5.96°, for pitch angle it is equal to 4.98° with standard deviation of 1.62°, and for roll angle it is about 0.06° with standard deviation of 2.31°, respectively.

7

А Меаsuring Method for Gyro-Free Determination of the Parameters of Moving Objects

Dichev D., Koev H., Bakalova T., Louda P.

Metrology and Measurement Systems

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2016

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Vol. 23, nr 1

107--118

EN

The paper presents a new method for building measuring instruments and systems for gyro-free determination of the parameters of moving objects. To illustrate the qualities of this method, a system for measuring the roll, pitch, heel and trim of a ship has been developed on its basis. The main concept of the method is based, on one hand, on a simplified design of the base coordinate system in the main measurement channel so as to reduce the instrumental errors, and, on the other hand, on an additional measurement channel operating in parallel with the main one and whose hardware and software platform makes possible performing algorithms intended to eliminate the dynamic error in real time. In this way, as well as by using suitable adaptive algorithms in the measurement procedures, low-cost measuring systems operating with high accuracy under conditions of inertial effects and whose parameters (intensity and frequency of the maximum in the spectrum) change within a wide range can be implemented.

8

Estimation of rotation angles based on GPS data from a UX5 Platform

Wierzbicki D., Krasuski K.

Measurement Automation Monitoring

|

2015

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Vol. 61, No. 11

516--520

EN

Data integration from INS and GPS sensors is applied in aeronautical navigation as a basic conception for determination of aircraft position. A GPS sensor is used to estimate coordinates (X, Y, Z) and velocity (Vx, Vy, Vz) also in a navigation solution. On the other hand, an INS sensor provides rotation angles (heading, pitch and roll) and acceleration parameters (Ax, Ay, Az). The GPS sensor is preferred to obtain an approximate value of rotation angles. In this paper, the results of studies on determination of heading, pitch and roll angles using GPS technology are presented. For this purpose, GPS data from a single-frequency L1 receiver from a UX5 platform were used. Calculations were executed in the HPR_GPS software, whose source code was written in Scilab 5.4.1 language. The software operation and an algorithm for estimation of heading, pitch, roll angles there is described. The preliminary results of rotation angles from the HPR_GPS software show that heading, pitch and roll values are very similar to raw INS measurements. The mean difference between the GPS data (after Kalman filter operation) and the INS data for the heading angle is equal to 0.32( with a standard deviation of 5.41(, for the pitch angle is equal 4.98( with a standard deviation of 5.06( and for the roll angle is about 0.06( with a standard deviation of 0.69).

9

Modeling and numerical simulation of semi-automatic pistol dynamics

Suchocki C., Ewertowski J.

Journal of Theoretical and Applied Mechanics

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2015

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Vol. 53 nr 1

81--91

EN

In this study, a mathematical model of a semi-automatic hand-held weapon is presented. The dynamical equations of motion are derived by utilizing the formalism of Lagrange equations of the second kind. The model is applied to describe motion of P-64 semi-automatic pistol. The characteristics of rheological elements accounting for the mechanical reaction of the human hand are identified and are further used to determine the force and torque which act on the human hand during a shot. Some exemplary results of the conducted parametric study are presented in order to illustrate sensitivity of the system.

10

Quality assessment of intonation of choir singers using F0 and trend lines for singing sequence

Półrolniczak E., Łazoryszczak M.

Metody Informatyki Stosowanej

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2011

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nr 4

259-268

EN

In this paper a part of quality assessment process of the intonation of singing voice is described. Intonation is understood here as the ability to precisely reproduce a given pitch. Such evaluation is typically performed by voice production experts (voice trainers) or other persons associated with singing. For the purpose of determining the quality of intonation an exercise performed by singers on subsequent pitches was proposed in the article. One of pitch extraction methods is used to determine the fundamental frequency and estimate the F0 trajectory. Based on the obtained trajectory, an attempt is made to determine a general trend among tested singers. It is also indicated, that it is possible to point out problems in singing for tested persons, which can be useful in further stages of voice training.

11

Perceptually Correlated Parameters of Musical Instrument Tones

Beauchamp J. W.

Archives of Acoustics

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2011

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Vol. 36, No. 2

225-238

EN

In Western music culture instruments have been developed according to unique instrument acoustical features based on types of excitation, resonance, and radiation. These include the woodwind, brass, bowed and plucked string, and percussion families of instruments. On the other hand, instrument performance depends on musical training, and music listening depends on perception of instrument output. Since musical signals are easier to understand in the frequency domain than the time domain, much effort has been made to perform spectral analysis and extract salient parameters, such as spectral centroids, in order to create simplified synthesis models for musical instrument sound synthesis. Moreover, perceptual tests have been made to determine the relative importance of various parameters, such as spectral centroid variation, spectral incoherence, and spectral irregularity. It turns out that the importance of particular parameters depends on both their strengths within musical sounds as well as the robustness of their effect on perception. Methods that the author and his colleagues have used to explore timbre perception are: 1) discrimination of parameter reduction or elimination; 2) dissimilarity judgments together with multidimensional scaling; 3) informal listening to sound morphing examples. This paper discusses ramifications of this work for sound synthesis and timbre transposition.

12

Absolute Pitch and Its Frequency Range

Rakowski A., Rogowski P.

Archives of Acoustics

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2011

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Vol. 36, No. 2

251-266

EN

This paper has two distinct parts. Section 1 includes general discussion of the phenomenon of “absolute pitch” (AP), and presentation of various concepts concerning definitions of “full”, “partial” and “pseudo” AP. Sections 2–4 include presentation of the experiment concerning frequency range in which absolute pitch appears, and discussion of the experimental results. The experiment was performed with participation of 9 AP experts selected from the population of 250 music students as best scoring in the pitch-naming piano-tone screening tests. Each subject had to recognize chromas of 108 pure tones representing the chromatic musical scale of nine octaves from E0 to D#9. The series of 108 tones was presented to each subject 60 times in random order, diotically, with loudness level about 65 phon. Percentage of correct recognitions (PC) for each tone was computed. The frequency range for the existence of absolute pitch in pure tones, perceived by sensitive AP possessors stretches usually over 5 octaves from about 130.6 Hz (C3) to about 3.951 Hz (B7). However, it was noted that in a single case, the upper boundary of AP was 9.397 Hz (D9). The split-halves method was applied to estimate the reliability of the obtained results.

13

Design solutions and active safety increasing for "VZN" shock absorbers

Niculescu A. I.

Journal of KONES

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2007

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Vol. 14, No. 4

295-306

EN

The paper presents the principle, some design solutions and last theoretical and by simulation results, for the suspension realized with the self-adjustable shock absorber, called shortly VZN, relative to the standard one. The self-adjustable shock absorber VZN, an intelligent shock absorber, realized without electronics or mechanisms, grant with European Patent EP1190184B and Romanian Patent 118546, is much better than standard ones because confers possibilities of stepwise adjustment of damping force as function as the instantaneous piston position. That means lower damping coefficients at the stroke beginning, for easier medium position arriving for a well adherence, damping coefficients for well correspondence between comfort and adherence, in the medium area, high damping coefficients both adjacent parts at the medium area for better adherence and well axle movement brake, and very high damping coefficients at the ends, for better body and axles protection. This concept is realized with planar or circular valves, a new patent request presenting specific solution. The cheaper and compact solution uses metering holes like damping valves, some of these being presented in the paper. The theory shows its great damping coefficient evolution with the stroke, give progressive anti-gyration effect and regressive redressing gyration effect along vehicle body transversal and longitudinal axes, increasing pitch and roll stability. Simulation tests denote high performances for VZN shock absorbers, relative to standard one, its great adaptation capacity relative to load, road condition, and efficiency, better body stability-skyhook behaviour, better protection at the stroke ends, lower RMS body acceleration, improving pitch and roll stability at and so active safety increasing. So the automotive self-adjustable shock absorber VZN, confers high performances, nearly semi-active suspensions at low costs, nearly standard shock absorbers being an important option for the future.

14

Speaking fundamental frequency of original speakers and their imitators

Majewski W.

Archives of Acoustics

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2007

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Vol. 32, No. 1

17-23

EN

The results of SFF measurements of well-known Polish personalities and their imitations performed by cabaret entertainers are presented and discussed. The difference in F0 between the original speakers and their imitators was in some cases few Hz only, but in some other cases it reached more than 100 Hz.

15

On the place code for pitch: a psychophysiological paradox in the classical concept

Zwislocki J. J.

Archives of Acoustics

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2007

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Vol. 32, No. 3

447--454

EN

The place of maximum excitation in the cochlea has been believed to be the code for the pitch of tones since mid 19-th century. More recent physiological experiments have revealed that, in a healthy cochlea, the maximum is displaced gradually toward the cochlear base (input) as the sound pressure is increased, whereas the pitch remains practically constant. This paradox suggests that the maximum excitation may not be the adequate code for the pitch after all. In the presence of hearing loss of cochlear origin, the pitch appears higher than normal. As the sound pressure level is increased, it changes gradually back to normal. By contrast, the maximum of cochlear excitation in the presence of cochlear damage, although displaced toward the cochlear base, remains independent of sound pressure level. In both situations, normal and pathological, the apical cut off of cochlear excitation depends on the sound pressure level in the same way as does the pitch. Could the cut off be the adequate place code for the pitch?

16

Mothers and their offspring perceive the tritone paradox in closely similar ways

Deutsch D.

Archives of Acoustics

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2007

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Vol. 32, No. 3

517--528

EN

The tritone paradox is produced when two tones that are related by a half-octave (or tritone) are presented in succession, and the tones are so constructed that their pitch classes (C, C#, D; and so on) are clearly defined but their pitch heights are ambiguous. When listeners judge whether such tone pairs form ascending or descending patterns, their judgments show orderly relationships to the positions of the tones along the pitch-class circle: Tones in one region of the circle are heard as higher and those in the opposite region as lower. However, listeners disagree substantially as to which tones are heard as higher and which as lower, and these perceptual differences correlate with the language or dialect to which the listener has been exposed. In the present study, perceptions of mothers and their offspring were found to be strikingly similar, indicating that the mental representation influencing perception of the tritone paradox is formed early in life and survives into adulthood. It is conjectured that this mental representation is formed during the critical period in which infants acquire the features of their native language.

17

Experiments on long-term and short-term memory for pitch in musicians

Rakowski A., Rogowski P.

Archives of Acoustics

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2007

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Vol. 32, No. 4

815--826

EN

A series of experiments on the memory for pitch was performed with 18 musicians. They had to pass a pitch-naming and a newly-designed pitch-producing test meant to check their passive and active absolute-pitch ability. On that ground two of them, who revealed faultless, full absolute pitch and one who had most typical relative (non-absolute) pitch, were selected to take part in a case-study-type experiment on short-term memory for pitch. The experiment partly confirmed the previous finding (RAKOWSKI, [5]) of the about 2-minute time range for short-term pitch memory in relative-pitch listeners. It also explained cases in which absolute pitch possessors, when required to repeat after short-term delay an external pitch standard, either use for that purpose their authentic short-term memory for pitch, or rather relay on comparisons with their absolute-pitch standards.

18

Absolute pitch: Common traits in music and language

Rakowski A., Miyazaki K.

Archives of Acoustics

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2007

|

Vol. 32, No. 1

5-16

EN

Absolute pitch in music means an ability of long-term auditory memory to store pitch standards corresponding to within-octave musical pitch classes, based on a generally recognized reference pitch. Such an ability, extremely rare among Western musicians, appears much more commonly among musicians of Asiatic countries. Hypothetically, it is due to either the special forms and early beginnings of musical education (Japan), or to a sort of "preconditioning" of the pitch-memory system in infants and very young children, to treat pitch value as a meaningful element of speech communication (countries with tone languages). Similarities and differences between absolute pitch in music and the memory for pitch value in tone languages will be discussed in detail.

19

Wyznaczanie częstotliwości podstawowej tonu krtaniowego za pomocą dyskretnej transformaty falkowej

Wilk B.

Zeszyty Naukowe Politechniki Rzeszowskiej. Elektrotechnika

|

2006

|

z. 29 [233]

301-306

PL

Jednym z ważniejszych parametrów charakteryzujących źródło mowy dźwięcznej jest częstotliwość podstawowa tonu krtaniowego (ang. fundamental frequency, pitch, F0), która odpowiada częstości drgań fałd głosowych. W artykule zaproponowano metodę wyznaczania częstotliwości podstawowej tonu krtaniowego, która bazuje na wielorozdzielczej dekompozycji widma mocy sygnału mowy. Wspomnianą metodę zastosowano do analizy pojedynczo wypowiadanych głosek dźwięcznych.

EN

One of the basie parameters characterizing voiced speech is the fundamental frequency (the so-called pitch, F0), which corresponds to the rate of the vocal folds vibration. In this paper, the new method for determining fundamental frequency is proposed. This method is based on the multiresolution decomposition of speech signal power spectrum. The mentioned method was applied to some isolated voiced vowels.

20

Pozyskiwanie danych do tworzenia numerycznego modelu DNA

Makar A., Naus K.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2003

|

Vol. 13a

163--170

PL

W artykule przedstawiono proces pozyskiwania danych do tworzenia numerycznego modelu dna, zarówno morskiego, jak i akwenów śródlądowych. Ze względu na wykorzystywanie w pomiarach morskich tych samych systemów pozycyjnych, co w pomiarach lądowych, scharakteryzowano wyłącznie aparaturę do pomiaru głębokości oraz urządzenia do pomiarów towarzyszących. Przedstawiono technologię prowadzenia pomiarów, zakłócenia ruchu jednostki pomiarowej oraz możliwości zwiększenia dokładności pomiarów hydrograficznych.

EN

In this paper has been shown the process of obtaining of data for digital model of sea and inland bottom. Because of usage during sea surveys and terrestrial measurements these same positioning systems, there have been described only instruments for depth and accompanying measurements. There also have been presented the technology of surveying, movement disruptions of the sounding vessel and possibilities of increasing the accuracy of the hydrographic surveys.