Showing papers in "Optoelectronics, Instrumentation and Data Processing in 2015"
TL;DR: In this paper, a combined adaptive control system for periodic modes of a control-affine a priori uncertain nonlinear dynamic object is considered, and the quality of the resulting control system is illustrated.
Abstract: A problem of constructing a combined adaptive control system for periodic modes of a control-affine a priori uncertain nonlinear dynamic object is considered. At the stage of simulation modeling, the quality of the resulting control system is illustrated.
19 citations
TL;DR: A special metric is proposed to identify embedded clusters even in the presence of overlapping and the efficiency of HCA and HECA hierarchical clustering algorithms for segmentation of multispectral images has been confirmed.
Abstract: Computationally efficient HCA and HECA hierarchical clustering algorithms for segmentation of multispectral images have been developed using the grid and ensemble approaches. A special metric is proposed to identify embedded clusters even in the presence of overlapping. The efficiency of the algorithms has been confirmed by the results of experimental studies using model and real data.
17 citations
TL;DR: In this article, a method for describing the spread function of a confocal X-ray microscope that allows for its retuning and accounts for the effect of the angular tuning errors is proposed and experimentally proved.
Abstract: A confocal experimental scheme with two polycapillary lenses is used to analyze the nearsurface layers of samples by X-ray fluorescent microanalysis with an accuracy of up to 10 μm. To increase the spatial resolution, it is required to account for the influence of the spread function of the confocal X-ray optical node. It is interesting to experiment with a tunable aperture of the confocal volume. In this case, the contribution of tuning inaccuracies in the spread function can increase. A method for describing the spread function of a confocal X-ray microscope that allows for its retuning and accounts for the effect of the angular tuning errors is proposed and experimentally proved. The method is based on the use of an approximating expression of the type of asymmetric approximation of the “Gaussian beam caustic”.
13 citations
TL;DR: A method of calculating the torque driving the aircraft to a prescribed attitude using the Euler angles between the axes of the body-fixed coordinate system and the Earth frame is proposed.
Abstract: The problem of control of the aircraft attitude in a three-dimensional space is considered. The attitude is described by the Euler angles between the axes of the body-fixed coordinate system and the Earth frame. A method of calculating the torque driving the aircraft to a prescribed attitude is proposed. A controller implementing this method is presented. Results of simulations are reported.
11 citations
TL;DR: A cuckoo search algorithm for identifying the parameters of fuzzy approximators and classifiers is presented and the results of experiments on eight sets of data from the KEEL repository are described.
Abstract: A cuckoo search algorithm for identifying the parameters of fuzzy approximators and classifiers is presented. The results of experiments on eight sets of data from the KEEL repository are described. Comparison with analogs are given.
11 citations
TL;DR: The VsDC2 and VsDC3 multifunctional integrators developed at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences are presented, based on the digital integration method which provides an error smaller than 10−5 for a wide class of measurements.
Abstract: This paper presents the VsDC2 and VsDC3 multifunctional integrators developed at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences for measurements of both constant and pulsed magnetic fields. These integrators are based on the digital integration method which provides an error smaller than 10−5 for a wide class of measurements. The method used in the developed devices allows accurate synchronization of an integration interval with pulsed signals, while the ADC used in the measuring channel is clocked by an asynchronous and low clock frequency. The theoretical aspects of the proposed solutions are considered and compared with known methods of constructing digital integrators. The circuitry of these devices is briefly described, and the main characteristics are given.
10 citations
TL;DR: In this paper, an approach is proposed to perform a mathematical analysis of an ordered relief formed on the nanotitanium surface after laser shock-wave treatment, which enables one to obtain informative attributes and a quantitative estimate of parameters of morphological structures being formed with allowance for the stochastic and cyclic nature of this process.
Abstract: An approach is proposed to perform a mathematical analysis of an ordered relief formed on the nanotitanium surface after laser shock-wave treatment. This approach enables one to obtain informative attributes and a quantitative estimate of parameters of morphological structures being formed with allowance for the stochastic and cyclic nature of this process.
10 citations
TL;DR: In this paper, the current status of the elements of uncooled infrared imaging arrays based on thermal insulation of their sensors and on accumulation of heat in the element volume during the time necessary for taking one frame is considered.
Abstract: The current status of the list of elements of uncooled infrared (IR) imaging arrays based on thermal insulation of their sensors and on accumulation of heat in the element volume during the time necessary for taking one frame is considered. Specific features of operation and the structure of resistive microbolometers and pyroelectric elements are described, as well as typical parameters of these elements. Prospects of improving the parameters of thermally insulated sensors of megapixel arrays are considered. It is noted that the main factor limiting further improvement of the parameters of pixels in IR imaging arrays and increasing the size of the latter is the value of the thermal resistance between the sensor and the substrate. At the modern level of technology development, the thermal resistance has actually reached the limiting value. Another physical principle of operation of IR detectors is required for a further increase in the sensitivity of sensors, a decrease in their response time, and an increase in the size of uncooled megapixel IR arrays; this principle should not include the necessity of thermal insulation of IR detectors. The operation principle based on using pyrotechnical effects will be considered in the second part of the paper.
10 citations
TL;DR: The synthesis of models of reconfigurable computing environments for some problems of binary image processing is considered, and the results of their operation are demonstrated.
Abstract: The paper deals with the use of high-performance computing systems with a parallel-operation architecture to solve problems of image processing. The idea of using reconfigurable computing environments is set out. The synthesis of models of reconfigurable computing environments for some problems of binary image processing is considered, and the results of their operation are demonstrated.
9 citations
TL;DR: In this paper, a possible approach to the calculation of standard controller parameters based on the localization method is considered, and the controllers designed in this way completely solve the problem of stabilization of first and second-order nonlinear nonstationary plants.
Abstract: A possible approach to the calculation of standard controller parameters based on the localization method is considered. It is shown that the controllers designed in this way completely solve the problem of stabilization of first- and second-order nonlinear nonstationary plants. Variants of implementation of standard controllers and recommendations for calculating their parameters are presented and the properties of the obtained automatic systems are investigated. It is noted that a general characteristic feature of systems with the proposed PID controller is the occurrence of fast motion components against the background of slow work processes. Results of numerical modeling illustrate the main properties of the systems considered.
9 citations
TL;DR: The most important results of the development and manufacturing of unique optoelectronic measurement and laser technologies and systems for various purposes aimed at solving urgent problems in industry and academic research, which are obtained at the Technological Design Institute of Scientific Instrument Engineering of the Siberian Branch of the Russian Academy of Sciences, are reviewed as discussed by the authors.
Abstract: The most important results of the development and manufacturing of unique optoelectronic measurement and laser technologies and systems for various purposes aimed at solving urgent problems in industry and academic research, which are obtained at the Technological Design Institute of Scientific Instrument Engineering of the Siberian Branch of the Russian Academy of Sciences, are reviewed. Technical characteristics of developed devices and systems and results of their testing at industrial enterprises and research institutes of the Siberian Branch of the Russian Academy of Sciences are reported.
TL;DR: In this paper, a method for direct laser thermochemical writing of gray-scale microimages in thin chromium films is developed and studied, which includes exposing a chromium film with a focused laser beam with variable power intensity and developing it in a selective etchant.
Abstract: A method for direct laser thermochemical writing of gray-scale microimages in thin chromium films is developed and studied. The method includes exposing a chromium film with a focused laser beam with variable power intensity and developing it in a selective etchant. The range of variation of the transmission by more than 100 times is obtained. The nonlinearity of the dependence of the chromium film transmission on the power intensity of the exposing beam is eliminated by software correction. The samples of the raster (with a size of 64×64 and a step of 176 μm) of apertures (36 μm) with the gray-scale Gaussian transmission function are manufactured experimentally. This raster is used in the modified Shack — Hartmann sensor.
TL;DR: It is shown that application of the hierarchical 3DRS algorithm with operation parameters determined in this work can substantially increase its noise immunity and reduce the computational cost.
Abstract: An approach to automatic determination of operation parameters of a hierarchical 3D recursive search (3DRS) algorithm is proposed and tested. A comparative study of the computational speed and noise immunity of the 3DRS algorithm used for constructing displacement vector fields, including the use of the Gaussian pyramids (hierarchical search), is performed. It is shown that application of the hierarchical 3DRS algorithm with operation parameters determined in this work can substantially increase its noise immunity and reduce the computational cost.
TL;DR: The shape of the diffractive structure of a deflecting kinoform element designed for focusing high-power laser beams with a wavelength of 10.6 µm is studied in this article.
Abstract: The shape of the diffractive structure of a deflecting kinoform element designed for focusing high-power laser beams with a wavelength of 10.6 µm is studied. Formulas are derived for calculating light losses induced by tilting of the incident beam, diffraction, and technological blurring of the steep slope of the structure. It is demonstrated that the height of the structure varies from the minimum to the maximum value depending on the azimuthal angle. It is found that light loss induced by shadowing due to oblique incidence of the beam is rather low (0.6–1.3%), and that caused by diffraction is smaller by an order of magnitude and can be neglected. The light losses induced by technological blurring of the slope and by deviation of the structure height from the design value (in the case of violation of the azimuthal dependence) can exceed 10%.
TL;DR: A nonparametric estimate of the decision function in a two-alternative problem of pattern recognition is considered and a technique of construction of confidence boundaries for the Bayesian equation of the separating surface is derived.
Abstract: A nonparametric estimate of the decision function in a two-alternative problem of pattern recognition is considered. The principle of expansion of the learning sample and the analysis of the probabilistic characteristics of the obtained sets of random variables are used to synthesize this estimate. On this basis, a technique of construction of confidence boundaries for the Bayesian equation of the separating surface is derived. The efficiency of this technique is proved by results of computational experiments.
TL;DR: The proposed method of structural synthesis allow one to form control inputs for robots–followers only on the basis of information about the relative positions of the followers and the leader without using the absolute values of the spatial coordinates of the robots.
Abstract: A problem of control of the motion of mobile robots with a differential drive in a leader–follower formation is considered. The proposed method of structural synthesis allow one to form control inputs for robots–followers only on the basis of information about the relative positions of the followers and the leader without using the absolute values of the spatial coordinates of the robots. The algorithm efficiency is confirmed by results of numerical experiments.
TL;DR: In this paper, a new method for measuring radial and axial displacements of complex-shaped blade tips with the help of a distributed cluster of two single-coil eddy-current sensors with sensitive elements made as conductor strips is described.
Abstract: A new method for measuring radial and axial displacements of complex-shaped blade tips with the help of a distributed cluster of two single-coil eddy-current sensors with sensitive elements made as conductor strips is described. The main distinctive features of the method and the results of an experimental analysis of families of calibration characteristics of both sensors are considered. This analysis proves a higher sensitivity to changes in radial displacements and an extended range of axial displacement measurements of the new method as compared to the existent one.
TL;DR: In this article, the physical and technical principles of readout integrated circuit (ROIC) for reading and preprocessing IR focal plane array signals in the infrared spectral range 8-14 μm were presented.
Abstract: This paper presents the physical and technical principles of readout integrated circuit (ROIC) for reading and preprocessing focal plane array signals in the infrared spectral range 8–14 μm. The noise equivalent temperature difference of long-wavelength infrared focal plane arrays based on ROIC with frame integration of signals of multilayer quantum well structures is evaluated. The influence of technological limitations in silicon readout circuits for photo signals on the performance of IR focal plane arrays is analyze for a wide range of parameters of QWIP -based focal plane arrays and CMOS technology design rules.
TL;DR: The problem of contactless control of an unmanned aerial vehicle by human gestures is considered and a system of commands is proposed for an AR.Drone 2.0 quadcopter equipped with a builtin computer, two color video cameras, the Linux operating system, and sensors for measuring the flight height, speed, and stability.
Abstract: The problem of contactless control of an unmanned aerial vehicle by human gestures is considered. A system of commands is proposed for an AR.Drone 2.0 quadcopter equipped with a builtin computer, two color video cameras, the Linux operating system, and sensors for measuring the flight height, speed, and stability. An Asus Xtion Pro Live three-dimensional sensor based on triangulation and structured light is used to enter data into the control system. Gesture recognition is performed by frame-by-frame processing of a video sequence consisting of depth images. The method does not require initial training, is insensitive to changes in lighting, and is invariant to the sizes of the human palm and body.
TL;DR: It is concluded that it is preferred to use thermal images to solve the problem of identifying operators during interaction with a technical system of thermal and visible face imaging.
Abstract: This problem of identifying operators during interaction with a technical system of thermal and visible face imaging is considered. The informativeness of the facial asymmetry feature is estimated. It is concluded that it is preferred to use thermal images to solve the problem. Estimates of the probabilities of correct identification of operators are obtained.
TL;DR: In this paper, a method for measuring a phase difference between two interfering wavefronts on the basis of analyzing the trajectories that are formed by the intensities of pairs of points in a series of interferograms with different phase shifts is proposed.
Abstract: A method for measuring a phase difference between two interfering wavefronts on the basis of analyzing the trajectories that are formed by the intensities of pairs of points in a series of interferograms with different phase shifts is proposed. This method does not require a priori knowledge of the actual values of phase shifts.
TL;DR: In this paper, a precision magnetometer based on pulsed nuclear magnetic resonance (NMR) is described, which can measure constant magnetic fields with an absolute error not more than 10−6 and a resolution of up to 10−7.
Abstract: A precision magnetometer based on pulsed nuclear magnetic resonance (NMR) is described. This magnetometer measures constant magnetic fields with an absolute error not more than 10−6 and a resolution of up to 10−7. The use of modern digital technologies, such as FPGA, made it possible to significantly accelerate and optimize NMR signals. The magnetometer structure is and the signal processing methods are described, measurement errors are analyzed, and experimental data are presented.
TL;DR: In this paper, it was shown that the problem of estimating unmeasurable external perturbations from a mathematical point of view is equivalent to estimating some of the state variables of an extended plant.
Abstract: It is shown that the problem of estimating unmeasurable external perturbations from a mathematical point of view is equivalent to estimating some of the state variables of an extended plant. An algorithm for estimating unmeasurable external perturbations using a functional observer is proposed, and conditions for the solvability of the synthesis problem are formulated. The resulting solution is obtained using the method of matrix canonization.
TL;DR: A method of synthesis of a self-adjusting multichannel system with a reference model for centralized control of autonomous underwater vehicle motion is developed, ensuring a high quality of control of an underwater vehicle with significant variations of its parameters.
Abstract: A method of synthesis of a self-adjusting multichannel system with a reference model for centralized control of autonomous underwater vehicle motion is developed. Conditions of selfadjustment process stability with allowance for dynamic reciprocal effects and kinematic relations between all control channels in the presence of parametric nonstationarity of the complete nonlinear mathematical model of the vehicle are obtained. The amplitude of the self-adjustment signal is formed as a function of coordinates and reference-input signals in order to reduce the control signal magnitude. The developed system ensures a high quality of control of an underwater vehicle with significant variations of its parameters.
TL;DR: In this paper, the results of experimental studies on quantum key distribution in optical fiber using superconducting detectors were presented, where key generation was obtained on an experimental setup based on a self-compensation optical circuit with an optical fiber length of 101.1 km.
Abstract: This paper presents the results of experimental studies on quantum key distribution in optical fiber using superconducting detectors. Key generation was obtained on an experimental setup based on a self-compensation optical circuit with an optical fiber length of 101.1 km. It was first shown that photon polarization encoding can be used for quantum key distribution in optical fiber over a distance in excess of 300 km.
TL;DR: In this paper, the authors presented a method for calculating the cross-wind speed at the entrance aperture of an adaptive system from the coordinates of the energy centers of gravity of the focal spots measured by a Shack-Hartmann wavefront sensor.
Abstract: This paper presents a method for calculating the cross-wind speed at the entrance aperture of an adaptive system from the coordinates of the energy centers of gravity of the focal spots measured by a Shack–Hartmann wavefront sensor. The range of applicability of the method are determined for data obtained in an experiment on an atmospheric path depending on the intensity of turbulent distortions and the optical parameters of the sensor.
TL;DR: An algorithm for detecting quasiperiodic textures is proposed, which is based on specific features of two-dimensional spectra obtained by using the discrete Fourier transform, and it is shown that the algorithm stably operates with significant deformations in the lattice of periodic textures.
Abstract: An algorithm for detecting quasiperiodic textures is proposed, which is based on specific features of two-dimensional spectra obtained by using the discrete Fourier transform. The power spectra of the fragments are analyzed independently of each other, which provides the computational effectiveness of the detection algorithm. Examples demonstrating the use of the detection algorithm in the problem of image segmentation into two texture classes (periodic and nonperiodic) are presented. It is shown that the algorithm stably operates with significant deformations in the lattice of periodic textures.
TL;DR: In this article, a goniometric-energy method of passive detection and ranging is developed, which makes it possible to determine the slant range of the radiating target with partly known parameters of its motion.
Abstract: One of the aspects of passive detection and ranging associated with using amplitude (power) measurements in single-position direction finders is discussed. For such a motionless direction finder, a goniometric-energy method of passive detection and ranging is developed, which makes it possible to determine the slant range of the radiating target with partly known parameters of its motion. A solution for a three-dimensional case with due allowance for the nonstationary character of the radio detection and ranging generalized coefficient is obtained. A complex algorithm of comprehensive estimation of this coefficient and the range for the model of straightline uniform motion of the target is constructed. Results of a computational experiment are presented, which confirm the possibility of using the developed method in practice.
TL;DR: In this paper, a semi-parametric spline regression model with variable penalty coefficients is proposed, which is based on the representation of the original model in the form of a random-effects model.
Abstract: The problem of constructing a semi-parametric spline regression model is considered. A new model of penalty splines with variable penalty coefficients is proposed. In the model, it is assumed that the coordinates of the basis points are determined by solving the optimization problem of minimizing the residual sum of squares. The choice of values of the penalty coefficients is based on the representation of the original model in the form of a random-effects model (variance component model). A series of computer simulation experiments was performed to reconstruct the regression line with different noise levels and in the presence of outliers. The results of computational experiments to reconstruct the regression line are presented that show greater accuracy of the new model in comparison with conventional models.
TL;DR: A method for optimizing geometric objects such as polygons and triangulated piecewise planar surfaces for the purposes of greater detailing and providing visual smoothness of their images is proposed.
Abstract: In this paper, we propose a method for optimizing geometric objects such as polygons and triangulated piecewise planar surfaces, for the purposes of greater detailing and providing visual smoothness of their images. The initial object is treated as a geometric realization of a simplicial scheme. The method involves refining the simplicial scheme and biharmonic interpolation of the embedding function of a subdivision of the simplicial scheme in Euclidean space.