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Wyszukujesz frazę "filter" wg kryterium: Temat


Tytuł:
Modification of robust filtering of stratified surface topography
Autorzy:
Dobrzański, P.
Pawlus, P.
Powiązania:
https://bibliotekanauki.pl/articles/220827.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
two-process surfaces
digital filtering
robust filter
valley suppression filter
modification of filter
Opis:
Various components of surface texture are identified, namely form, waviness and roughness. Separation of these components is done by digital filtering. Several problems exist during analysis of two-process surfaces. Therefore the Gaussian robust profile filtering technique was established and has been studied here. The computer generated 2D profiles and 3D surface topographies having triangular scratches as well as measured stratified surfaces were subjected to filtration. However even robust filter applications cause distortion of profiles having valleys wider than 100 ěm. In order to minimize the distortion associated with wide and deep valleys, the robust filter should be modified. A special procedure was elaborated for minimizing distortion of roughness profiles caused by filtration. Application of this method to analyses of several profiles was presented. The difference between 1-D and 2-D filtering of surface topography using the same kind of filter was discussed. As a result we found that modification of a 2-D surface topography filter was not necessary.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 107-118
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An efficient method of group delay equalization for digital IIR filters
Autorzy:
Okoniewski, P.
Piskorowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/220738.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
IIR filter
digital filter
group delay
phase response
genetic algorithm
equalizer
Opis:
The paper presents the equalization problem of non-linear phase response of digital IIR type filters. An improved analytical method of designing a low-order equalizer is presented. The proposed approach is compared with the original method. The genetic algorithm is presented as an iterative method of optimization. The vector and matrix representation of the all-pass equalizer are shown and introduced to the algorithm. The results are compared with the analytical method. In this paper we have also proposed the use of an aging factor and setting the initial population of the genetic algorithm around the solution provided by the analytical methodology.
Źródło:
Metrology and Measurement Systems; 2013, 20, 3; 395-406
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast estimation of the non-stationary amplitude of a harmonically distorted signal using a Kalman filter
Autorzy:
Kovač, U.
Košir, A.
Powiązania:
https://bibliotekanauki.pl/articles/220868.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
amplitude estimation
harmonic signal
harmonic distortion
Kalman filter
Opis:
In this paper we introduce a self-tuning Kalman filter for fast time-domain amplitude estimation of noisy harmonic signals with non-stationary amplitude and harmonic distortion, which is the problem of a contactvoltage measurement to which we apply the proposed method. The research method is based on the self-tuning of the Kalman filter's dropping-off behavior. The optimal performance (in terms of accuracy and fast response) is achieved by detecting the jump of the amplitude based on statistical tests of the innovation vector of the Kalman filter and reacting to this jump by adjusting the values of the covariance matrix of the state vector. The method's optimal configuration of the parameters was chosen using a statistical power analysis. Experimental results show that the proposed method outperforms competing methods in terms of speed and accuracy of the jump detection and amplitude estimation.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 27-42
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Employing a Savitzky-Golay Filtering Stage to Improve Performance of Spectrum Sensing in CR Applications Concerning VDSA Approach
Autorzy:
Angrisani, L.
Capriglione, D.
Cerro, G.
Ferrigno, L.
Miele, G.
Powiązania:
https://bibliotekanauki.pl/articles/220369.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cognitive radio
smoothing filter
VDSA
spectrum sensing
spectral measurements
Opis:
In this paper, a filtering stage based on employing a Savitzky-Golay (SG) filter is proposed to be used in the spectrum sensing phase of a Cognitive Radio (CR) communication paradigm for Vehicular Dynamic Spectrum Access (VDSA). It is used to smooth the acquired spectra, which constitute the input for a spectrum sensing algorithm. The sensing phase is necessary, since VDSA is based on an opportunistic approach to the spectral resource, and the opportunities are represented by the user-free spectrum zones, to be detected through the sensing phase. Each filter typology presents peculiarities in terms of its computational cost, de-noising ability and signal shape reconstruction. The SG filtering properties are compared with those of the linear Moving Average (MA) filter, widely used in the CR framework. Important improvements are proposed.
Źródło:
Metrology and Measurement Systems; 2016, 23, 2; 295-308
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A maintenance-free solution for optical frequency transfer
Autorzy:
Włodarczyk, Przemysław
Krehlik, Przemysław
Śliwczyński, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/220794.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fiber-optics
optical frequency transfer
tracking filter
automatic startup
Opis:
This paper focuses on automatic locking of tracking filters used in optical frequency transfer systems. General concept of such a system is briefly described and the problems with its automatic startup, originating in the use of the analog phase locked loop to filter weak, received signal, are discussed. A supervisory circuitry and algorithm to solve these problems is proposed. The frequency of the signal to be filtered is measured indirectly and the output frequency of the tracking filter is monitored. In the case of lack of synchronism (i.e. after the startup) a significant difference of these frequencies is measured and the supervisory algorithm forces the filter to tune into the right frequency and then allows it to synchronize. A system with the proposed solution was implemented and tested experimentally on a fiber optic link with high attenuation and multiple optical connectors. Transient signals during locking were recorded to investigate the system’s behavior in real environment. The system was evaluated in the link causing synchronization losses every 17 min on average. During measurements over 3 days, the whole system was synchronized for over 99.98% of time despite these difficult conditions.
Źródło:
Metrology and Measurement Systems; 2020, 27, 3; 441-450
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kalman filter based method for fault diagnosis of analog circuits
Autorzy:
Li, X.
Xie, Y.
Bi, D.
Ao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/221517.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog fault diagnosis
signature extraction
Kalman filter
Shannon entropy
Opis:
This paper presents a Kalman filter based method for diagnosing both parametric and catastrophic faults in analog circuits. Two major innovations are presented, i.e., the Kalman filter based technique, which can significantly improve the efficiency of diagnosing a fault through an iterative structure, and the Shannon entropy to mitigate the influence of component tolerance. Both these concepts help to achieve higher performance and lower testing cost while maintaining the circuit.s functionality. Our simulations demonstrate that using the Kalman filter based technique leads to good results of fault detection and fault location of analog circuits. Meanwhile, the parasitics, as a result of enhancing accessibility by adding test points, are reduced to minimum, that is, the data used for diagnosis is directly obtained from the system primary output pins in our method. The simulations also show that decision boundaries among faulty circuits have small variations over a wide range of noise-immunity requirements. In addition, experimental results show that the proposed method is superior to the test method based on the subband decomposition combined with coherence function, arisen recently.
Źródło:
Metrology and Measurement Systems; 2013, 20, 2; 307-322
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved classification robust Kalman filtering method for precise point positioning
Autorzy:
Zhang, Qieqie
Zhao, Long
Zhou, Jianhua
Powiązania:
https://bibliotekanauki.pl/articles/220468.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kalman filter
classification robust
equivalent weight function
precise point positioning
Opis:
The accuracy and reliability of Kalman filter are easily affected by the gross errors in observations. Although robust Kalman filter based on equivalent weight function models can reduce the impact of gross errors on filtering results, the conventional equivalent weight function models are more suitable for the observations with the same noise level. For Precise Point Positioning (PPP) with multiple types of observations that have different measuring accuracy and noise levels, the filtering results obtained with conventional robust equivalent weight function models are not the best ones. For this problem, a classification robust equivalent weight function model based on the t-inspection statistics is proposed, which has better performance than the conventional equivalent weight function models in the case of no more than one gross error in a certain type of observations. However, in the case of multiple gross errors in a certain type of observations, the performance of the conventional robust Kalman filter based on the two kinds of equivalent weight function models are barely satisfactory due to the interaction between gross errors. To address this problem, an improved classification robust Kalman filtering method is further proposed in this paper. To verify and evaluate the performance of the proposed method, simulation tests were carried out based on the GPS/BDS data and their results were compared with those obtained with the conventional robust Kalman filtering method. The results show that the improved classification robust Kalman filtering method can effectively reduce the impact of multiple gross errors on the positioning results and significantly improve the positioning accuracy and reliability of PPP.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 267-281
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sideslip angle estimation of in-wheel motor drive electric vehicles by cascaded multi-Kalman filters and modified tire model
Autorzy:
Chen, Long
Chen, Te
Xu, Xing
Cai, Yingfeng
Jiang, Haobin
Sun, Xiaoqiang
Powiązania:
https://bibliotekanauki.pl/articles/220947.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
distributed drive electric vehicle
Kalman filter
error compensation
sideslip angle
Opis:
Reliable estimation of longitudinal force and sideslip angle is essential for vehicle stability and active safety control. This paper presents a novel longitudinal force and sideslip angle estimation method for four-wheel independent-drive electric vehicles in which the cascaded multi-Kalman filters are applied. Also, a modified tire model is proposed to improve the accuracy and reliability of sideslip angle estimation. In the design of longitudinal force observer, considering that the longitudinal force is the unknown input of the electric driving wheel model, an expanded electric driving wheel model is presented and the longitudinal force is obtained by a strong tracking filter. Based on the longitudinal force observer, taking into consideration uncertain interferences of the vehicle dynamic model, a sideslip angle estimation method is designed using the robust Kalman filter and a novel modified tire model is proposed to correct the original tire model using the estimation results of longitudinal tire forces. Simulations and experiments were carried out, and effectiveness of the proposed estimation method was verified.
Źródło:
Metrology and Measurement Systems; 2019, 26, 1; 185-208
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new predictive filter for nonlinear alignment model of stationary MEMS inertial sensors
Autorzy:
Alhassan, Hassan Majed
Ghahremani, Nemat Allah
Powiązania:
https://bibliotekanauki.pl/articles/2052163.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
predictive filter
nonlinear alignment
model error
optimization
MEMS inertial sensors
Opis:
This paper proposes a new approach called the Predictive Kalman Filter (PKF) which predicts and compensates model errors of inertial sensors to improve the accuracy of static alignment without the use of external assistance. The uncertain model error is the main problem in the field as the Micro Electro Mechanical System (MEMS) inertial sensors have bias which change over time, and these errors are not all observable. The proposed filter determines an optimal equivalent model error by minimizing a quadratic penalty function without augmenting the system state space. The optimization procedure enables the filter to decrease both model uncertainty and external disturbances. The paper first presents the complete formulation of the proposed filter. Then, a nonlinear alignment model with a large misalignment angle is considered. Experimental results demonstrate that the new method improves the accuracy and rapidness of the alignment process as the convergence time is reduced from 550 s to 50 s, and the azimuth misalignment angle correctness is decreased from 52′′ ± 47′′ to 4′′ ± 0.02′′.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 673-691
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quaternion-based filtering for gyroless attitude estimation without an attitude dynamics model
Autorzy:
Zhang, S.
Xing, F.
Sun, T.
You, Z.
Powiązania:
https://bibliotekanauki.pl/articles/220655.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quaternion-based filtering
gyroless attitude estimation
angular velocity determination
Kalman filter
Opis:
Conventionally, the filtering technique for attitude estimation is performed using gyros or attitude dynamics models. In order to extend the application range of an attitude filter, this paper proposes a quaternion-based filtering framework for gyroless attitude estimation without an attitude dynamics model. The attitude estimation system is established based on a quaternion kinematic equation and vector observation models. The angular velocity in the system is determined through observation vectors from attitude sensors and the statistical properties of the angular velocity error are analysed. A Kalman filter is applied to estimate the attitude error such that the effect from the angular velocity error is compensated with its statistical properties at each sampling moment. A numerical simulation example is presented to illustrate the performance of the proposed algorithm.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 631-643
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Algorithm for Improving the Accuracy of Systems Measuring Parameters of Moving Objects
Autorzy:
Dichev, D.
Koev, H.
Bakalova, T.
Louda, P.
Powiązania:
https://bibliotekanauki.pl/articles/221344.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kalman filter
adaptive algorithm
dynamic measurements
dynamic error
adaptive measuring systems
Opis:
The paper considers an algorithm for increasing the accuracy of measuring systems operating on moving objects. The algorithm is based on the Kalman filter. It aims to provide a high measurement accuracy for the whole range of change of the measured quantity and the interference effects, as well as to eliminate the influence of a number of interference sources, each of which is of secondary importance but their total impact can cause a considerable distortion of the measuring signal. The algorithm is intended for gyro-free measuring systems. It is based on a model of the moving object dynamics. The mathematical model is developed in such a way that it enables to automatically adjust the algorithm parameters depending on the current state of measurement conditions. This makes possible to develop low-cost measuring systems with a high dynamic accuracy. The presented experimental results prove effectiveness of the proposed algorithm in terms of the dynamic accuracy of measuring systems of that type.
Źródło:
Metrology and Measurement Systems; 2016, 23, 4; 555-565
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparisons of envelope morphological filtering methods and various regular algorithms for surface texture analysis
Autorzy:
Podulka, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/220525.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface texture
surface topography measurement
envelope filter
morphological filtering
measurement errors
Opis:
In this paper both envelope approach and morphological filters for characterisation of surface textures were proposed, applied and thoroughly examined. Obtained results were compared with those received after appliance of commonly-used algorithms. The effect of appliance of proposed procedures on surface topography parameters (from ISO 25178 standard) was taken into consideration. The following types of surface textures were assessed: two-process plateau-honed cylinder liners, plateau-honed cylinder liners with additionally burnished dimples, turned piston skirts, grinded and/or isotropic topographies. It was assumed that envelope characteristics (envelope filtration) can provide results useful for assessments of deep and/or wide oil-reservoirs especially when they are edge located. Moreover, some near-valley areas of surface texture details can be less distorted when envelope filtering is accomplished. It was also found that closing and/or opening envelope filtration can be valuable for reduction of some surface topography measurement errors.
Źródło:
Metrology and Measurement Systems; 2020, 27, 2; 243-263
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Improved Robust Kalman Filter in Data Fusion for PPP/INS Tightly Coupled Positioning System
Autorzy:
Li, Z.
Yao, Y.
Wang, J.
Gao, J.
Powiązania:
https://bibliotekanauki.pl/articles/221374.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PPP/INS tightly coupled positioning
robust filter
IGG scheme
Mahalanobis distance
Opis:
A robust Kalman filter improved with IGG (Institute of Geodesy and Geophysics) scheme is proposed and used to resist the harmful effect of gross error from GPS observation in PPP/INS (precise point positioning/inertial navigation system) tightly coupled positioning. A new robust filter factor is constructed as a three-section function to increase the computational efficiency based on the IGG principle. The results of simulation analysis show that the robust Kalman filter with IGG scheme is able to reduce the filter iteration number and increase efficiency. The effectiveness of new robust filter is demonstrated by a real experiment. The results support our conclusion that the improved robust Kalman filter with IGG scheme used in PPP/INS tightly coupled positioning is able to remove the ill effect of gross error in GPS pseudorange observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all simulated gross errors added to GPS pseudorange observation are successfully detected and modified.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 289-301
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
64 channel neural recording amplifier with tunable bandwidth in 180 nm CMOS technology
Autorzy:
Gryboś, P.
Kmon, P.
Żołądź, M.
Szczygieł, R.
Kachel, M.
Lewandowski, M.
Błasiak, T.
Powiązania:
https://bibliotekanauki.pl/articles/220527.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
neurobiological measurements
low noise amplifier
neural recording
band-pass filter
multichannel ASIC
Opis:
This paper presents the design and measurements of low-noise multichannel front-end electronics for recording extra-cellular neuronal signals using microelectrode arrays. The integrated circuit contains 64 readout channels and is fabricated in CMOS 180 nm technology. A single readout channel is built of an AC coupling circuit at the input, a low-noise preamplifier, a band-pass filter and a second amplifier. In order to reduce the number of output lines, the 64 analog signals from readout channels are multiplexed to a single output by an analog multiplexer. The chip is optimized for low noise and good matching performance and has the possibility of passband tuning. The low cut-off frequency can be tuned in the 1 Hz - 60 Hz range while the high cut-off frequency can be tuned in the 3.5 kHz - 15 kHz range. For the nominal gain setting at 44 dB and power dissipation per single channel of 220 žW, the equivalent input noise is in the range from 6 žV - 11 žV rms depending on the band-pass filter settings. The chip has good uniformity concerning the spread of its electrical parameters from channel to channel. The spread of the gain calculated as standard deviation to mean value is about 4.4% and the spread of the low cut-off frequency set at 1.6 Hz is only 0.07 Hz. The chip occupies 5×2.3 mm⊃2 of silicon area. To our knowledge, our solution is the first reported multichannel recording system which allows to set in each recording channel the low cut-off frequency within a single Hz with a small spread of this parameter from channel to channel. The first recordings of action potentials from the thalamus of the rat under urethane anesthesia are presented.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 631-643
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fir Filters Compliant with the IEEE Standard for M Class PMU
Autorzy:
Duda, K.
Zieliński, T. P.
Powiązania:
https://bibliotekanauki.pl/articles/221798.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phasor estimation
Phasor Measurement Unit
FIR filter
cosine window
flat-top window
Opis:
In this paper it is shown that M class PMU (Phasor Measurement Unit) reference model for phasor estimation recommended by the IEEE Standard C37.118.1 with the Amendment 1 is not compliant with the Standard. The reference filter preserves only the limits for TVE (total vector error), and exceeds FE (frequency error) and RFE (rate of frequency error) limits. As a remedy we propose new filters for phasor estimation for M class PMU that are fully compliant with the Standard requirements. The proposed filters are designed: 1) by the window method; 2) as flat-top windows; or as 3) optimal min-max filters. The results for all Standard compliance tests are presented, confirming good performance of the proposed filters. The proposed filters are fixed at the nominal frequency, i.e. frequency tracking and adaptive filter tuning are not required, therefore they are well suited for application in lowcost popular PMUs.
Źródło:
Metrology and Measurement Systems; 2016, 23, 4; 623-636
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł

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