A semi-Markov stationary model of operation of measuring instruments installed on complex technical systems is developed, which allows modelling the process of metrological maintenance of measuring instruments at combined verification and operational automated condition control. The results of modelling are presented.

Keywords: semi-Markov model, measuring instrument, verification, operational automated state control

The drilling and blasting method is currently the most widely used for mining rocks. An indicator of the high–quality drilling and blasting operations is the uniform granulometric composition of the exploded rock mass - the percentage of oversized ore pieces should be minimal. The percentage of oversized and its increase have a significant impact on the technical processes of transporting rock mass, leading to an increase in the costs of loading and transportation operations and secondary crushing of oversized ore masses. The paper describes the results of a study of methods for determining the granulometric composition of drilling and blasting operations using neural networks of segmentation Unet and FPN. Images taken from UAVs are used for analysis. A method of classifying ore by size has also been developed, which ensures the accuracy of the proportion of correct answers of more than 0.91. The expected result of the introduction of the system for automatic determination of the granulometric composition of drilling and blasting operations is the possibility of more accurate control over the quality of their performance.

Keywords: granulometric composition, Unet, FPN, classification, segmentation

The article discusses a method for detecting defects in extended products. To find defects, scanning the product along its entire length is used. The result is a two-dimensional data stream that needs to be analyzed. The problem of detecting a defect is one of the tasks of detecting a “useful” signal against a background of “noise”. The most reliable method is to use a set of statistical criteria. To compare the mean values, the Student's test and two Wilcoxon–Mann–Whitney tests were used; to compare the scattering values, the Fisher test and the Ansari–Bradley test were used. The effectiveness of the algorithm was confirmed using a computer model simulating a two-dimensional homogeneous data stream.

Keywords: defects, extended products, computer model, simulation, statistical criterion

Prism spectral devices have a spectrum-variable dispersion and therefore a nonlinear relationship between the wavelength and the position of spectral lines on the focal surface of a spectral monochromator device, which makes it difficult to calibrate such devices in terms of wavelengths and dispersion.Most often, the well-known Hartmat formula is used for graduation. However, the accuracy of its calculation is satisfactory only in a limited spectral range, and therefore the calculation is carried out on overlapping areas no wider than 200 nm with averaging in overlapping zones. Averaging gives a calibration curve (and, accordingly, a dispersion curve) with gaps at the joints. In this paper, we consider the possibility of using a single calibration for the entire spectrum region, providing smooth, continuous calibration curves. The best result is obtained by using the Hartmann formula for the entire spectral range, after which a set of deviations of the calibration points is determined. This set is interpolated by a polynomial of an arbitrarily chosen order n using the least squares method.

Keywords: monochromator, spectrum, calibration, dispersion, Hartmann formula, interpolation, polynomial

The article discusses a method for detecting local areas with hidden defects in products whose length is several orders of magnitude greater than other dimensions, when processing information from non-destructive testing of the product. To obtain the necessary information, various means of introscopy and radiation of different nature are used. Processing of information obtained using scanning control should detect areas with defects and determine their nature. To compare different processing methods and select the optimal method for processing information, a computer modeling method was used, with the help of which the process of obtaining information and processing it was simulated, which simplifies the selection of the most suitable method for detecting a defect. The article describes typical models of the received signal and presents the simulation results.

Keywords: defects, non-destructive testing, extended products, simulation model, moving averaging, time series

The problem of atmospheric air pollution by dust particles, along with the formation of greenhouse gases, covers many countries of the world. To monitor the state of atmospheric air, expensive and cumbersome monitoring stations are traditionally used, for which state organizations are responsible. The use of inexpensive sensor particle sensors that will allow real-time measurements at the border of the sanitary protection zone of industrial enterprises and on the territory of the residential zone opens up new prospects in the field of atmospheric air research. Currently, about 10 thousand inexpensive sensors operate on the territory of 75 countries of the world, which causes the involvement of citizens in the collection of data on the state of atmospheric air. The presented technology for monitoring the concentration of fine particulate matter can replace the traditional measurement method, but the question remains of the value of the data obtained in terms of their accuracy. This article discusses the factor influencing the deviation of the readings of the inexpensive Nova SDS011 solid particle sensor. To do this, the sensor was tested in real environmental conditions, experimental dependences of the concentration of dust particles of no more than 2.5 micrometers depending on humidity were obtained.

Keywords: atmospheric air, PM2.5, Nova SDS011 sensor, dust particle concentration, monitoring stations, relative humidity

The paper is devoted to the application of the simplex optimization algorithm in the field of magnetic measurements, namely in measuring the demagnetization curve of highly coercive magnetic materials. The algorithm has found its place in the implementation of a new method based on the full-scale model approach and the Gills-Atterton hysteresis model, the essence of which is also described in the work. It is expected that the new method will make it possible to more accurately determine the demagnetization curve of permanent magnets by using voltage meters instead of classical induction sensors, which will avoid the accumulation of error. The simplex optimization algorithm makes it possible to optimize the parameters of the Gills-Atterton model in such a way that the simulated mathematical model of a highly coercive magnetic material best corresponds to the measured magnetic material. The method is tested on a multiphysical model built in the COMSOL Multiphysics software package and includes calculations of an inductor and a permanent high-coercive magnet.

Keywords: permanent magnet, neodymium magnet, highly coercive material, magnetic material, Fourier-Bessel decomposition, approximation, momentum, optimization, simplex, Nelder-Mead algorithm, mathematical model, coercive force, hysteresis