A neural network model is proposed for a strapdown inertial navigation system (SINS) entering an integrated inertial-satellite navigation system of an autonomous aircraft, operating in the conditions of loss of satellite radio navigation field signals. The model takes into account the main factors that define the errors in navigation parameters estimates by means of the SINS, including the dynamics of the aircraft functioning process. As essential parameters characterizing the autonomous aircraft flight mode dynamics, it is proposed to use linear and angular accelerations, as well as their variations in the discrete interval of the navigation system operation. A functional diagram of the inertial-satellite navigation system with the neural network model of SINS errors is presented, and recommendations are given for its specific implementation.

On the example of a system of dynamic authentication of an operator of a workstation of a critically important object, ways are shown to increase the reliability of recognizing the legitimacy of a user by the absence of deviations in his behavior. A variant of the well-known computer handwriting identification algorithm is considered. Directions for improving the composition and methods of professional psycho-physical selection of candidates for the position of operators of an automated workplace of critically important objects are studied.

Methodological errors of an electronic sensor, built on the basis of the ultrasonic method for monitoring the parameters of the incoming air flow (IAF), are analyzed. The sensor satisfies the increasing requirements for design simplification, weight and cost reduction, for the slip angle measurement range while simultaneously measuring the angle of attack. It is shown that the methodological errors of the electronic sensor of the airspeed vector parameters are of an aerodynamic nature and are associated with disturbances of the IAF during the aircraft movement and the flow around the fuselage with a fixed receiver of the IAF parameters installed on the fuselage. The IAF disturbances introduced by the movement and flow around the aircraft increase the local true airspeed perceived on the fuselage at the installation site of a fixed receiver with pairs of combined emitters-receivers of ultrasonic vibrations of the considered electronic sensor located on it. An expression is obtained that determines the influence of IAF disturbances on the value of the true airspeed measured by an electronic sensor at the location of a fixed receiver. Analytical models are obtained and the calculation of the methodological error in determining the true airspeed in the operating speed and altitude ranges of small aircraft operation are carried out. It is shown that IAF disturbances at the location of the fixed receiver of the electronic sensor also cause methodological errors in determining the indicated speed and Mach number, the angle of attack and the sideslip angle with the considered electronic sensor. Methodological errors in determining the indicated airspeed and Mach number in the actual ranges of small-sized aircraft operation are calculated from the local true airspeed measured by an electronic sensor. It is shown that the methodological error in measuring the sideslip angle due to the symmetry of the aircraft in the plane of change in the angle of attack can be neglected. The aerodynamic errors of the considered electronic sensor are due to an increase in the local true airspeed at the location of the electronic sensor on the aircraft fuselage, therefore the main direction of their reduction is the introduction of aerodynamic corrections into the output signals of the electronic sensor using the calculated values of aerodynamic errors.

Optical systems of 6-color superachromats with corrected longitudinal chromatic aberration in a wide spectral range are studied. An algorithm for automatic synthesis of three-lens objective with corrected longitudinal chromatic aberration in a wide spectral range is developed. Synthesis of apochromats is performed on the basis of the thirdorder aberrations theory. The method of exhaustive search of calculated objectives from a user-specified catalog of materials is applied. A two-stage ranking system of calculated objectives, taking into account the axial point image quality and the sensitivity of the objective to manufacturing errors, is proposed. Solutions for three-lens 6-color superachromats in the spectral range 365–1000 nm are found. The design parameters of several options of practical interest are given. The presented apochromats and superachromats can be used as objectives of telescopic systems or collimators.

Dynamic vibration testing is an important component of small spacecraft ground testing program. As a rule, nanosatellites are placed on the desktop of vibration stands by means of simulators of a transport and launch container (STPC). Results of modernization of the simulator of transport-launch container statically fixed on the table of the vibrating stand, as well as of the rotary complex, which includes the modernized STPC, are presented. For both structures, model dynamic vibration studies are carried out in SolidWorks CAD. For a statically fixed STPC, the maximum amount of the resonating mass of the structure is 0,048 % over the entire range of specified frequencies, the deformations are close to zero, while for the modernized STPC with a rotary device, the resonating mass is 0,27 %, and the deformations of the nodes complex – 0,09 mm. For the base of the rotary device, static deformations are studied separately; using numerical simulation, a value of 0,057 mm is obtained, and in full-scale tests – 0,052 mm, which indicates a high factor of the structure safety. The modernized STPC with a rotary device, fixed on the table of the shaker, has a greater resonant mass and deformation than the statically fixed STPC, however, the values of these parameters lie within the acceptable limits according to GOST 30630.0.0-99 (p. 6), which allows the operation of the designed rotary complex for nanosatellites dynamic vibration testing. Application of the complex makes it possible to replace expensive vibration stands that create dynamic vibration loads in two or more independent planes, since it can be used on vibration stands that create vibrations in only one direction.

To predict the safe state of reinforced concrete structures at transport infrastructure facilities, information on directions of crack opening in such structures is of principle importance. The cracks appearance is due to formation and increase in the amount of hydrated iron oxide (iron hydroxide) on the reinforcing bars, that is, caused by corrosion processes. Particularly dangerous are cases when reinforced concrete structures are manufactured in violation of the requirements. The paper considers a case of using steel reinforcement pins of different diameters. The presented results of calculations obtained using mathematical modeling of the nonlinear behavior of corrosion processes and the resulting deformation and structural destruction of concrete show the model forms and direction of crack opening.

Ellipsometry is an effective tool for measuring the optical constants and structural parameters of the surface – the interface between media, studying the physical and chemical processes occurring on the surface. The purpose of the work is to create a working layout of a millimeter-range ellipsometer optimized for a frequency of 140 GHz. In creation of the millimeter-wave ellipsometer, original quasi-optical elements developed earlier are used - linear and circular polarizers, made in the form of thin-film polymer-based metasurfaces. Experimental studies of quasi-optical elements characteristics and methodological errors due to the "imperfection" of the elements are carried out. The results of measurements of the optical constants of composite materials based on carbon fibers in the range of 140 GHz are presented. An ellipsometric experiment is performed to detect internal defects in composite products. The results of the study make it possible to conclude that millimeter-range ellipsometry may be used successfully in solving problems of surface engineering in the study of micro-heterogeneous dispersion systems.

Application of the spectrophotometric method for studying ethyl alcohol in some types of beer products is considered. The optical spectroscopy methods make it possible to conduct a quantitative and qualitative analysis of the composition of a substance. These methods are highly accurate, informative, reliable, as well as economical and widely used due to the availability of instrumentation, ease of obtaining and interpreting information, so the work is relevant and promising. The spectrophotometer appearance is presented, optical scheme and the technical characteristics of the device are given. The spectral dependences of the absorption coefficient of the proportion of ethyl alcohol in different sorts of beer are obtained and analyzed. The maximum absorption in the presented liquid-phase media is found in the wavelength range from 200 to 1100 nm.

In modern automated control systems for complex objects (ACS CO), the processes of obtaining, storing, processing and transmitting data, information and knowledge are closely intertwined with the processes of monitoring and managing these objects. At the same time, these processes can proceed both sequentially and in parallel, using various resources of the ACS CO. The analysis shows that within the framework of existing approaches, when describing the processes under consideration, the dynamic nature of the partial order that arises between them is not taken into account. Such a dynamically changing partial order in previous publications is proposed to be called the natural parallelism of the processes of functioning of the ACS CO. In these papers, it is shown that with automatic purposeful dynamic parallelization of processes, high efficiency is achieved in the use of the resulting models in the control of complex objects. The implemented parallelism is close to the natural parallelism of the simulated processes. At the same time, the execution of processes using dynamic parallelization is distinguished by the possibility of scaling to a different number of parallel interpreters (processors, parallel threads). In this article, a possible approach to formal description of the natural parallelism of management and information processes is proposed.

The classical linear regression equation is considered, containing the measured signal in the left part and the sum of terms consisting of the product of unknown parameters and known functions (regressors) in the right part. A distinctive feature of the considered equation from the classical one is the assumption that the unknown parameters are non-linear combinations of one. Namely, each of the unknown parameters is obtained by raising one unknown parameter to a power. The article proposes a new simplified procedure for searching for the unknown parameter, which, unlike the widely used gradient descent method, allows, on the one hand, to significantly simplify the identification algorithm, and, on the other hand, to expand the assumptions for regressors.

The importance of taking into account practical experience in the development of metrological standards is analyzed. Two main aspects are considered: the first is knowledge of the procedural features of the development stages, the second is the inclusion of the requirements of regulatory documents that ensure the quality of the performance of metrological tasks.

The need to introduce the root-mean-square roughness Rq into regulatory and design documents for optical surfaces is substantiated experimentally. It is noted that this parameter value makes it possible to estimate the energy losses associated with radiation scattering. The results of comparison of Rq and the arithmetic mean deviation of the profile Ra of optical surfaces, which are formed by polishing and diamond micro-turning, are presented. The absence of an unambiguous relationship between these characteristics is shown. The expediency of transition from 2D-metry to 3D-metry when normalizing and measuring roughness is observed; in particular, this is relevant in the case of a lack of symmetry in the roughness topography.