Information Processing Systems in UAV Based on Bayesian Filtering in Conditions of Uncertainty

2020 ◽  
Vol 12 (4) ◽  
pp. 42-59
Author(s):  
Rinat Galiautdinov
Keyword(s):  
Information Processing ◽  
Degrees Of Freedom ◽  
Adaptive Filters ◽  
A Priori ◽  
Practical Implementation ◽  
Bayesian Filtering ◽  
Math Model ◽  
Digital Implementation ◽  
Estimation Algorithms ◽  
A Priori Uncertainty

In this article, the author considers the possibility of applying modern IT technologies to implement information processing algorithms in UAV motion control system. Filtration of coordinates and motion parameters of objects under a priori uncertainty is carried out using nonlinear adaptive filters: Kalman and Bayesian filters. The author considers numerical methods for digital implementation of nonlinear filters based on the convolution of functions, the possibilities of neural networks and fuzzy logic for solving the problems of tracking UAV objects (or missiles), the math model of dynamics, the features of the practical implementation of state estimation algorithms in the frame of added additional degrees of freedom. The considered algorithms are oriented on solving the problems in real time using parallel and cloud computing.

Nonlinear Filtering in Artificial Neural Network Applications in Business and Engineering

2021 ◽  
pp. 1-23
Author(s):  
Rinat Galiautdinov
Keyword(s):  
Motion Control ◽  
Nonlinear Filtering ◽  
Degrees Of Freedom ◽  
Adaptive Filters ◽  
Practical Implementation ◽  
Math Model ◽  
Digital Implementation ◽  
Estimation Algorithms ◽  
Network Applications ◽  
Neural Network Applications

Within this chapter the author considers the possibility of applying modern IT technologies to implement information processing algorithms in the sphere of UAV motion control system. Filtration of coordinates and motion parameters of objects in the situation of uncertainty is carried out using nonlinear adaptive filters, such as: Kalman and Bayesian filters. The author considers numerical methods for digital implementation of nonlinear filters based on the convolution of functions, the possibilities of neural networks, and fuzzy logic for solving the problems of tracking UAV objects (or missiles), the math model of dynamics, the features of the practical implementation of state estimation algorithms in the frame of added additional degrees of freedom. The considered algorithms are oriented on solving the problems in real time using parallel and cloud computing.

Method for measuring distortions of a speech signal during its transmission over a communication channel to a biometric identification system

2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko
Keyword(s):  
Speech Signal ◽  
Communication Channel ◽  
Speaker Identification ◽  
A Priori ◽  
Small Samples ◽  
Practical Implementation ◽  
Identification System ◽  
New Information ◽  
Discrimination Criterion ◽  
A Priori Uncertainty

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.

ANALYSIS OF THE INFLUENCE OF A PRIORI UNCERTAINTY RELATING TO THE DISPERSION OF ADDITIVE NOISE ON THE OPERATION OF SIGNAL PARAMETERS ESTIMATION ALGORITHMS

2021 ◽  
Author(s):  
Н.Е. ПОБОРЧАЯ
Keyword(s):  
Nonlinear Filtering ◽  
Additive Noise ◽  
A Priori ◽  
Estimation Procedure ◽  
Parameters Estimation ◽  
Joint Estimation ◽  
Regularizing Algorithm ◽  
Estimation Algorithms ◽  
True Variance ◽  
A Priori Uncertainty

Проведен анализ работы регуляризующего алгоритма и процедуры нелинейной фильтрации в условиях неточного знания величины дисперсии аддитивного шума и анализ их вычислительной сложности. С помощью регуляризующих алгоритмов на фоне аддитивного и фазового шума оценивались параметры сигнала квадратурной амплитудной модуляции: сдвиг частоты, постоянные составляющие квадратур сигнала, амплитудный и фазовый дисбаланс, амплитуда и фаза сигнала. Показано, что их сложность ниже, чем у известной процедуры совместного оценивания, а регуляризующий алгоритм устойчивее процедуры нелинейной фильтрации к отклонению дисперсии аддитивного шума от истинных значений. Analysis of the operation of regularizing algorithm and procedure of nonlinear filtering in conditions of the imprecise value of the variance of the additive noise and analysis of their computational complexity were carried out. Using regularizing these algorithms against the background of additive and phase noise, the following parameters of the quadrature amplitude modulation signal were estimated: frequency shift, constant components of the signal quadrature, amplitude and phase imbalance, amplitude and phase of the signal. It is shown that their complexity is lower than that of the well-known joint estimation procedure, and also that the regularizing algorithm is more resistant to deviations from the true variance of the additive noise than the nonlinear filtering procedure.

Semihyper-Reduction for Finite Element Structures With Nonlinear Surface Loads on the Basis of Stress Modes

2020 ◽  
Vol 15 (8) ◽  
Author(s):  
Lukas Koller ◽  
Wolfgang Witteveen ◽  
Florian Pichler ◽  
Peter Fischer
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Hydrodynamic Lubrication ◽  
A Priori ◽  
Time Integration ◽  
Practical Implementation ◽  
Fe Model ◽  
Lubrication Film ◽  
Nonlinear Surface ◽  
Surface Loads

Abstract Model reduction via projection is a common method to accelerate time integration of finite element (FE) structures by reducing the number of degrees-of-freedom (DOFs). However, nonlinear state-dependent surface loads are usually computed based on the nonreduced DOFs of the FE model. When a considerably high number of DOFs are involved in the nonlinear surface loads, their computation becomes a bottleneck. This paper presents a general approach for reduced time integration and reduced force computation for FE models. The required force trial vectors can be computed easily and systematically out of deformation trial vectors, commonly called “modes.” Those force trial vectors, which we call “stress modes,” can be determined a priori so that a nonlinear computation of the full system is not necessary. The new idea in this contribution is that stress recovery is used to decrease the number of equations for the force computation. A general framework for semihyper-reduction (SHR) is developed and its practical implementation is discussed. The term SHR is introduced because it is an intermediate approach between the straight-forward method of using the FE DOFs and pure hyper-reduction (HR) where the FE DOFs are omitted for computing state-depended surface loads. In order to demonstrate the proposed SHR approach practically, a numerical example of a planar crank drive is given, where a hydrodynamic lubrication film separates piston and cylinder. Thereby, very good result quality has been observed in comparison to a finite difference reference solution.

COMBINATION OF LINEAR AND NONLINEAR ESTIMATION ALGORITHMS OF OFDM SIGNAL DISTORTION IN THE DIRECT CONVERSION RECEIVER

2020 ◽  
Author(s):  
Н.Е. ПОБОРЧАЯ
Keyword(s):  
Least Squares Method ◽  
A Priori ◽  
Spline Approximation ◽  
Direct Conversion ◽  
Joint Estimation ◽  
Distribution Law ◽  
Estimation Algorithms ◽  
Ofdm Signal ◽  
Signal Distortions ◽  
A Priori Uncertainty

В условиях априорной неопределенности закона распределения фазовых и аддитивных шумов предложен алгоритм совместной оценки стационарного канала и искажений сигнала OFDM, возникающих в приемнике прямого преобразования. Алгоритм основан на комбинировании: полиномиальной сплайн-аппроксимации и линейном методе наименьших квадратов; нелинейной фильтрации или регуляризующего алгоритма. Проведен экспериментальный анализ зависимости помехоустойчивости рассматриваемого алгоритма, работающего по двум тестовым OFDM-символам, от отношения сигнал/шум. Joint estimation of the stationary channel and OFDM signal distortions acquired in the direct conversion receiver under conditions of a priori uncertainty of distribution law of phase and additive noises is proposed. The algorithm is based on a combination of polynomial spline approximation and the linear least-squares method, as well as non-linear filtering procedures or regularizing algorithm. An experimental analysis of the dependence of the noise immunity of the considered algorithm, operating on two test OFDM symbols, is carried out.

scholarly journals Increasing the accuracy of signal extraction by correcting the approximating function under conditions of a priori uncertainty

2021 ◽  
Vol 279 ◽  
pp. 02003
Author(s):  
Ivan Nikishin ◽  
Vladimir Marchuk ◽  
Igor Shrayfel ◽  
Ilya Sadrtdinov
Keyword(s):  
Additive Noise ◽  
A Priori ◽  
Signal Extraction ◽  
Statistical Characteristics ◽  
Practical Implementation ◽  
Sample Length ◽  
Complex Signals ◽  
Useful Signal ◽  
A Priori Uncertainty ◽  
Measured Process

The paper discusses the issues of practical implementation of increasing the accuracy of signal extraction, which is achieved by eliminating the «flip» of the approximating function when dividing the measured process into intervals under conditions of a priori uncertainty about the signal function, which significantly increases the error of allocating a useful signal. The probability of a «flip» of the approximating function depends significantly on the variance of the additive noise and the sample length. The use of the proposed methods and their software implementation makes it possible to increase the accuracy of the useful signal extraction up to 30 percent in the absence of a priori information about the function of the measured process for complex signals and at least 20% for simpler ones. The use of the proposed methods will significantly increase the processing efficiency in the conditions of a priori uncertainty about the function of the measured process (useful signal) and the statistical characteristics of the additive noise components.

Detection of Changes in the Random Signal Properties by Spectral Methods Under the Conditions of A Priori Uncertainty

1999 ◽  
Vol 53 (9-10) ◽  
pp. 1-10
Author(s):  
V. A. Omel'chenko ◽  
V. V. Balabanov ◽  
B. M. Bezruk ◽  
Yu. N. Goloborod'ko
Keyword(s):  
Spectral Methods ◽  
A Priori ◽  
Random Signal ◽  
A Priori Uncertainty

The Influence of Loading Position in A Priori High Stress Detection using Mode Superposition

2020 ◽  
Vol 1 (1) ◽  
pp. 93-102
Author(s):  
Carsten Strzalka ◽  
◽  
Manfred Zehn ◽  
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
A Priori ◽  
High Stress ◽  
Von Mises Stress ◽  
Detailed Knowledge ◽  
Variable Loading ◽  
Numerical Effort ◽  
Von Mises

For the analysis of structural components, the finite element method (FEM) has become the most widely applied tool for numerical stress- and subsequent durability analyses. In industrial application advanced FE-models result in high numbers of degrees of freedom, making dynamic analyses time-consuming and expensive. As detailed finite element models are necessary for accurate stress results, the resulting data and connected numerical effort from dynamic stress analysis can be high. For the reduction of that effort, sophisticated methods have been developed to limit numerical calculations and processing of data to only small fractions of the global model. Therefore, detailed knowledge of the position of a component’s highly stressed areas is of great advantage for any present or subsequent analysis steps. In this paper an efficient method for the a priori detection of highly stressed areas of force-excited components is presented, based on modal stress superposition. As the component’s dynamic response and corresponding stress is always a function of its excitation, special attention is paid to the influence of the loading position. Based on the frequency domain solution of the modally decoupled equations of motion, a coefficient for a priori weighted superposition of modal von Mises stress fields is developed and validated on a simply supported cantilever beam structure with variable loading positions. The proposed approach is then applied to a simplified industrial model of a twist beam rear axle.

TAKING INTO CONSIDERATION OF THE MULTIPLE MODE OF THE FUNCTIONING AND CHARACTERISTICS OF THE CONTROL IN RELIABILITY MODELS OF REPLACEMENT TIME SYSTEMS

2019 ◽  
Author(s):  
Iryna Kononova
Keyword(s):  
A Priori ◽  
Telecommunication System ◽  
Structural Element ◽  
Reliability Models ◽  
Quick Recovery ◽  
Reliability Indicators ◽  
A Priori Uncertainty ◽  
Control Of Parameters ◽  
Time Systems ◽  
Time Reserve

The article evaluates the reliability indicators of telecommunication system equipment, which can be represented by multi-mode objects of continuous and episodic use with a time reserve operating under conditions of a priori uncertainty. Particular attention is paid to consideration of the process of functioning of the system with a replenished time reserve. The telecommunication system includes an object represented by one structural element and used in different modes of operation. In each mode, the object can be used continuously or episodically (the object performs tasks that occur at random times), herewith only a certain part of its equipment is operating. The restoration of the facility's operation in each mode is based on the "quick" recovery scheme ("quick" recovery means that the repair time is much less than the average working time of the element between failures). Also, some cases of the transition of an object from one mode to another are considered, and the control system operates according to the method of sequential control of parameters. In this case, the system, after waiting mode, begins to analyze the first parameter of the monitored complex, then the second and so on. After analyzing the parameters, the system enters the waiting mode. These calculated ratios allow for a comprehensive assessment of the reliability of telecommunication equipment, taking into account the totality of the main factors that significantly affect the reliability of the equipment in real conditions of operation, make it possible to solve important practical problems which arise from the improvement of existing equipment and development of existing equipment.

Spatial filtering of signals with spectrum overlapping

2019 ◽  
pp. 27-33
Author(s):  
M. E. Shevchenko ◽  
A. V. Gorovoy ◽  
S. N. Solovyov
Keyword(s):  
Antenna Arrays ◽  
A Priori ◽  
Spatial Filtering ◽  
Spatial Filter ◽  
Radio Sources ◽  
Probability Of Error ◽  
Shift Keying ◽  
A Priori Uncertainty

The paper considers the spatial filtering methods of signals with spectrum overlapping under conditions of a priori uncertainty of the directions of arrival from radio sources. The estimates of the directions of signals arrival obtained by ESPRIT or MUSIC are used in order to build a spatial filter. It is shown that when using ESPRIT, unlike MUSIC, an additional calculations of filter coefficients based on estimates of the directions of signals arrival are not required, and the quadrature components of the signals are formed simultaneously with estimates of the direction of their arrival. The probability of error performances of minimum shift keying signals which were divided by spatial filtering on the basis of ESPRIT and MUSIC using seven-element circular and angular antenna arrays are given.

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