ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
Summaries of the issue


Specific of Varshamov—Tenenholts codes application to the problems of construction of automa-tion systems with the account for possibilities of faults detecting as well as correcting their dangerous manifestations is considered. Principles of the Varshamov—Tenenholts codes construction are de-scribed, a brief analysis of characteristics of errors detected in code words is performed. A block diagram of the coding equipment for the codes under consideration is presented; the approach is based on the use of binary adders in the residue ring of arbitrary module known in advance and a comparator. The coding equipment allows to select from the complete set of binary code vectors of a given length those that form the corresponding Varshamov—Tenenholts code. Examples of the considered codes applica-tion in implementation of devices and automation systems with various properties of the architecture (fault detection, error correction) are given. Algorithms for the synthesis of fault-tolerant combinational and sequential automation devices based on the Varshamov—Tenenholts codes are proposed.
Results of studies of the "prevalence" of distribution laws in practice are presented. The basis of the studies is the entropy coefficient for parameters of various objects and processes. Inconsistency of the approach based on "total" approximation of the real distribution laws by the normal law when con-ducting research and organizing the management of objects of different nature is substantiated. It is ar-gued that accounting for variability of the analyzed parameter in the form of the entropy coefficient of a real distribution law increases the adequacy of descriptions of uncertainty states, which, in turn, affects the effectiveness of research and decision-making. It makes the methods and technologies of the theory of entropy potentials very convenient and useful "tools" for solving such problems in question. The theory potentialities allow monitoring and organization of control of uncertainty states of complex systems. The use of obtained results makes it possible to quickly assess the dominance of specific types of distribution laws in different situations when solving monitoring and control problems using the entropy approach.
The Alford method is a modern tool for estimating anisotropy from cross-dipole acoustic logging records. The azimuthal angle of the acoustic anisotropy direction  is estimated by the minimum cross energy of the converted records. The interval times (speeds) of the fast and slow bending wave pfast, pslow in the forward and reverse directions of anisotropy are estimated using the corresponding transfor-mations. Practical implementation of the method is considered, using the analytical solution of the min-imization problem.


The proposed approach to the problem of active vibration suppression of a distributed elastic ob-ject involves defining the transfer functions for each feedback loop of the control system being created. These functions are synthesized considering characteristics of the control object obtained either experi-mentally or numerically. An adequate model of the object is a key factor in the control system design since it allows one not only to obtain the object characteristics, but also to simulate the created system operation. The problem of active suppression of forced bending vibrations of a simply supported metal beam using piezoelectric sensors and actuators is analyzed. The objective of the study is to compare two different approaches to piezoelectric elements modeling during the process of creating the control sys-tem. The control laws synthesis is carried out using an optimization procedure, which allows selection of the optimal parameters of the filters that determine the transfer functions in the feedback loops of the created system. Results of the study demonstrate that application of a simplified model which does not accounts for the influence of the piezoelectric elements on the object vibrational modes, significantly re-duces the vibration suppression efficiency. However, for real objects this effect may be reduced by opti-mizing the gain values in the control loops of the obtained systems.


An adaptive optical system (AOS) intended for use in high-power pulsed laser installations of iner-tial thermonuclear fusion, is designed to provide the required spatial characteristics of the laser beam wavefront. The composition of the AOS includes: a deformable mirror (DM), a wave front sensor, an am-plifying unit, a computer for calculations and control. Increased requirements for the reliability of laser system components are dictated by the high cost of ownership. The least reliable components of the sys-tem are drives actuators (included in the DM), since they are subject to cyclic variable electromechanical loads. Technical solutions of AOS and the arising requirements to the system reliability are analyzed. The two most critical failures of the system are indicated; they are degradation of the optical properties of the coatings of the optical surface of the deformable mirror, and the loss of compensation possibilities. As dependability indicators for the elements of a system, the mean operating time to failure is proposed. Reliability of AOS as a whole may be characterized by an integrated reliability ratio, indicators of durabil-ity and persistence. Issues related to the reliability of AOS elements are considered. A block diagram of the AOS module is presented and an integrated reliability ratio - the effectiveness persistence coefficient - is evaluated. Reliability of the developed AOS is confirmed by tests of separate elements of the system. The created AOS elements are reported to meet requirements imposed to them.
The process of mechanical polishing of zinc selenide using a water-glycol suspension of ASM single crystal diamond and RDDM polycrystalline diamond is studied. Based on obtained results, a method for mechanical polishing of ZnSe is developed. The method is reported to provide the surface roughness of 0,227 nm, while deviation from planarity is less than one interference fringe, with a local error within 0,1 interference fringe.


DEVELOPMENT OF AN INFORMATION TECHNOLOGY PLATFORM FOR DIGITAL PRODUCTION Kamo V. Abramyan, Andreev Yury S, Anatoly A. Gorbenko, Sergey D. Tretyakov, Radda A. Yureva
Specific of the problem of creation an information technology platform for digital production is considered, and the approach to the problem based on the use of the industrial Internet of things com-ponents is described. Basic principles of building an information technology platform are formulated, and the main difficulties faced by creators of such systems are determined. The platform architecture is designed and tools for creating an information technology platform are specified; an algorithm of the platform functioning is developed. A prototype of the information technology platform based on a dis-tributed production site of the Faculty of Control System and Robotics at ITMO University is created. A connection is performed to the platform of production equipment located at various territorial sites. Fac-tors affecting the effectiveness of the information technology platform implementation for digital pro-duction are revealed, and the main stages of the implementation at the site of the industrial partner of ITMO University are determined.
Significant disadvantages of the effective method of filament winding in the manufacture of cy-lindrical composite products are noted. One of them is related to the fact that the tension values of the surface layer and the inner layers in the batch may vary significantly from product to product. Because of this, deviations of the winding density and other indicators of its stress-strain state from the set values are observed. To eliminate this and other drawbacks, a method for controlling the radial increment of the composite winding is proposed, which provides control of its density. An algorithm is presented which allows to design control actions in the end zones of the mandrel, where the clamshell is rotated in the opposite direction. The use of the algorithm is due to the need to maintain the same winding section over the entire width of the mandrel.
The process of wear of a flat sample from the insertion of a rotating disk under the influence of a constant normal load is considered. A model is proposed that allows for a correct estimation of both line-ar and mass wear intensity. Decomposition of the exact geometric formula for calculating segment height and area into the Taylor makes it possible to simplify calculation of the studied parameters de-pendence from the chord length. The proposed model is noted to have the following advantages: a sim-ple and technological design of the test sample in the form of a rectangular bar of small dimensions; ac-curate and simple determination of linear and mass wear along the length of the chord; possibility of conducting accelerated tests of the wear resistance of various materials both during abrasive wear and during tests with a lubricant. The described method effectiveness is confirmed by comparative testing of the wear resistance of several real materials with an assessment of the influence of certain technological factors.


A method for determining the conditions of maximum efficiency of a helium vapor flow cryostat designed to maintain a predetermined temperature level of the lens of a cryogenic optoelectronic de-vice is proposed. A mathematical model of the process of cryostatting object cooling with the use of a pipeline mounted on the surface of the object for a constant mass rate flow of helium vapors, is pre-sented. The pipeline contact with the object surface is assumed to be ideal. It is shown that it is neces-sary to ensure full recovery of helium vapors with the pipeline for the most efficient cooling with a mini-mum flow rate of cryoagent. Requirements for the length of the pipeline providing full recovery in the heat exchanger are determined using preliminary calculated thermal efficiency per unit length of the pipeline. This specific index of thermal efficiency (SITE) of the flow heat exchanger is an objective crite-rion of the condition of full recovery. Analytical formulas for calculating the thermal efficiency index for laminar, transient, and turbulent regimes of helium vapor flow are derived. The formulas represent the dependences on the mass flow rate and the diameter of the pipeline accounting for the cryostatting temperature level. The efficiency and convenience of the obtained analytical dependences for practical calculations, as well as for the choice of parameters of flow cryostats are demonstrated.
The active use of virtualization technologies in the construction of network infrastructures pro-vides the possibility of using new methods and tools to manage the components of these structures, which, in turn, expands the scope of solutions based on the concept of programmable (software-configurable) networks. Expanding the scope of implementation of such solutions, lead to increasing need for specialists who capable to combine knowledge of network technologies with programming skills. An approach to building the laboratory complex of an educational institution is proposed. The ap-proach is reported to allow for continuity in teaching network technologies and for providing students with practical skills of using modern methods of managing virtual components of network infrastructure. Application of such tools as Ansible platform, the libraries of the NCCLIENT and PyEZ programs for dy-namic management of virtual components of the hardware-software stand as part of the laboratory complex of software-configured network infrastructures of RTF UrFU is considered.


CONCEPT AND TECHNOLOGIES OF PROACTIVE MANAGEMENT OF PRODUCT LIFE CYCLE Mikhail Yu. Okhtilev , Boris V. Sokolov , Rafael M. Yusupov, Mark M. Styskin, Vladimir Un.-D. Gao
The basics of creating a new generation of technologies and systems for managing the life cycle of space rocket and aviation equipment products based on the implementation of proactive manage-ment methodology and technologies are considered.
The concept of heterogeneous workflows is formulated and following computational modes are identified: batch, streaming, and iterative. The necessity of developing of scheduling algorithms for each of modes is determined. Developed scheduling algorithms are based on machine learning methods, evolu-tionary approaches, and artificial intelligence methods. A technology has been developed that ensures the collaborative execution of heterogeneous workflows based on a cascade of developed optimization meth-ods.