### INFORMATION TECHNOLOGIES AND SYSTEMS, COMPUTER TECHNIQUE

WEIGHTED CODES WITH SUMMATION IN THE RING OF RESIDUES BY AN ARBITRARY MODULUS
FOR THE SYNTHESIS OF DIGITAL COMPUTING DEVICES
Ephanov Dmitry V., Artyom V. Pashukov

231

In the synthesis of self-checking and fault-tolerant digital computing systems, binary redundant codes are often used. Their use makes it possible to reduce structural redundancy in order to endow devices with the property of self-checking or fault tolerance. Results of the study of a wide class of codes with summation are presented, in the construction of which preselected sequences of weight coefficients and the summation procedure in the ring of residues by a preliminarily fixed modulus are used. Codes with three sequences of weight coefficients are considered: 1) natural numbers; 2) natural series except for powers of 2; 3) alternating sequences of increasing powers of the number 2. Characteristics of error detection by codes by multiplicities and types (monotonic, symmetric and asymmetric) are established. Conditions for constructing noise-immune codes, as well as methods for modifying codes to endow them with the property of noise immunity, are given. Results of experiments with control combinational circuits on the use of the described codes for error detection at their outputs are presented. The features of the use of modular weighted codes with summation in the synthesis of digital devices are discussed

### INSTRUMENTS AND SYSTEMS OF AUTOMATIC CONTROL

AUTONOMOUS METHOD FOR FORMING ESTIMATIONS
OF THE STAR TRACKERS ORIENTATION PARAMETERS
Danilova Tamara V. , Arkhipova Marina A. , Мarina А. Мaslova

247

A method is proposed for generating refined estimates of the position angles of star sensors rigidly fixed on the spacecraft body, in the presence of high-precision data on the orbit parameters. The instrumental errors in measuring stars coordinates by the sensors are several tenths of a second of arc. The estimates of the position angles of the trackers optical axes are determined by numerically solving a system of matrix equations. Application of the propose method leads to a significant, by one or two orders of magnitude, reduction in the errors in the orientation parameters of the instruments relative to the spacecraft body and, as a result, to formation of high-precision estimates of the spacecraft body orientation parameters in the geocentric and moving orbital coordinate systems. The resulting average errors do not exceed a few arcseconds, and sometimes decrease to the level of instrumental errors in measuring the coordinates of stars by the trackers. Results of modeling are presented and recommendations for the algorithm application are given.

### ELECTRONIC AND ELECTROMAGNETIC DEVICES

MULTI-CHANNEL TEMPERATURE CONVERTER
Oleg G. Bondar, Ekaterina О. Brezhneva, Pavel S. Rodionov

254

A method for multichannel temperature measurement is proposed, which consists in alternately supplying n resistance thermometers. The method makes it possible to increase the accuracy of measurement by weakening the influence of the resistance of the lines through which resistance thermometers are connected. A prototype of multichannel temper-ature converter is developed and used for the method testing.

### OPTICAL AND OPTO-ELECTRONIC INSTRUMENTS AND SYSTEMS

ALGORITHM FOR OBJECT ROTATION ANGLES MEASURING
BY THE AUTOCOLLIMATION METHOD
USING A TRIHEDRAL REFLECTOR WITH A CYLINDRICAL FACE
Mikhail M. Nikitin, Fedor G. Dobrykh, Konyakhin Igor A.

262

An algorithm for determining rotation angle of the control element for autocollimation system using the reflector in the form of a trihedral control element with a cylindrical face is proposed. This type of reflector is used to determine the three-dimensional angular spatial position of an object. A mathematical model of the reflector is created, which reproduces its interaction with the radiation. On the basis of obtained images, according to the model, an algorithm for determining the control element rotation angle is developed. The algorithm provides image filtering from noise; reducing the thickness of the lines on the image to improve the accuracy of determining the angle of rotation; imposition of a dark area on the center of the image, for the possibility of subsequent clustering of lines; directly determining the angle of rotation of the lines on the image for the subsequent determination of the angle of rotation of the control element. The algorithm makes it possible to analyze the pattern obtained from a reflector with more than one cylindrical face.

### SCIENTIFIC AND PRACTICAL DEVELOPMENTS

METHOD FOR FORMATION OF GROUP TIME SCALE
OF RADIO ENGINEERING COMPLEXES BASED
ON ADAPTIVE POLYNOMIAL DATA APPROXIMATION
Bakursky Klim V., Makarov Andrey A., Timothy O. Myslivtsev, Nikiforov Sergey V.

271

Corrections to onboard time scales of navigation space vehicles are analyzed, and results of processing of the time scales readings for n selected spacecrafts using a second-order polynomial approximation, are presented. A method for formation of a group time scale of radio engineering complexes based on adaptive polynomial data approximation is developed. Simulation modeling of the proposed variant of analytical group time scale formation is carried out.

EXPERIMENTAL EVALUATION
OF THE WEAR RESISTANCE OF A DISC-ON-DISC FRICTION PAIR
Leonid V. Efremov, Tikalov Andrey V.

280

Algorithms for estimating the wear of a rolling friction pair with slippage of the “disk on disk” type during tests on an SMC-2 friction machine are proposed. Three variants of the disc slip mode are given when simulating sliding and rolling friction on the example of main types of damage to gears. The algorithms for calculating the linear and volumetric wear resistance of discs, in the case of sliding friction against slippage, are based on the block-on-ring method. The work is supposed to be relevant for studying wear affecting factors. The proposed and substantiated technique is ready for use in testing friction pairs of the “disk-on-disk” type.

METHODS FOR ASSESSING A VEHICLE TECHNICAL CONDITION USING VIBRATION DIAGNOSTICS
Tkalich Vera L., Mariia E. Kalinkina, Korobeynikov Anatoliy Grigorievich, Pirozhnikova Olga I., Bibikov Sergey V

287

The advantages and disadvantages of existing methods for assessing the technical condition of vibration diagnostics of electrical equipment are considered. Available means of measuring vibration processes are reviewed, and the spectra of vibration amplitudes of transport engines are examined. The analysis shows that when searching for the limiting values of the characteristic function modulus for the instantaneous values of vibroacoustic signals that correspond to different states of the controlled object, the use of statistical methods, in particular the method of minimal risks, is required. This allows to find the threshold values of the signs of diagnosis based on the assessment of the risks of making a decision. In the course of the analysis of the vibro-acoustic signal, the characteristic function of instantaneous values is used. The probability density of the values of the function modulus is studied by the most accurate method of the minimum number of erroneous decisions.

EXAMINATION OF THE POST-INJECTION EPIDERMIS WITH A MODIFIED
MICHELSON-FIZEAU INTERFEROMETER
Aleksander V. Arefiev, Viktor V. Kurlov, Vladimir B. Kotskovich, Majorov Evgeniy E., Vera P. Pushkina, Udakhina Svetlana V.

295

The skin of patients before and after cosmetic procedures is studied in vivo with a modified Michelson-Fizeau interferometer. The relevance of the work is shown, since obtaining reliable data on the geometric parameters of the skin surface, its condition is important for every person. The surface relief of the skin around the eyes in patients aged 38–45 years is chosen as the object of the in vivo study. Optical and functional diagrams of the measuring system are given, as well as technical and operational characteristics. Experimental results are obtained for 10 patients. It is revealed that after the application of botulinum toxin, the skin becomes smoother and more elastic, there is practically no variation in the height of the relief.