DOI: 10.7256/2454-0714.2021.2.36014

Abstract:   This article examines the model of pursuit task, when the pursuer while moving in space, adheres to the strategy of constant-bearing approach. The velocity modules of the pursuer and target are constant. The object moves evenly and straightforwardly, for certainty of the model, since the test program is written based on the materials of the article. The velocity vectors of the target and the pursuer in the beginning of the pursuit are directed arbitrarily. The iterative process consists of the three parts. Calculation of trajectory of the pursuer in space, calculation of trajectory of the pursuer in a plane, calculation of the transition of trajectory from space to a plane are conducted. All parts of the iterative process have to meet the conditions specified in a task. An important condition is that the minimum radius of curvature of the trajectory should not exceed a certain set value. The scientific novelty of the geometric model consists in the possibility to regulate the time of reaching the target by changing the length of trajectory of the pursuer, as well as the orientation of a plane of pursuit. Calculation of the point of next position of the pursuer in space is the point of intersection of the sphere, cone and plane of constant-bearing approach. A plane of constant-bearing approach is perpendicular to a plane of pursuit. In the model under review, a plane of pursuit is determined by the target velocity vector and direct target that connects the pursuer and the target (sight line). The radius of the sphere is equal to the step of the pursuer for the time interval the time of the iterative process is divided into. The angle of solution of the cone is the angle by which the velocity vector of the pursuer can turn. The mathematical model presented in the article may be of interest to developers of unmanned aerial vehicles.  

DOI: 10.7256/2454-0714.2021.2.35433

Abstract: The goal of this research is to develop the theory and practice of synergetic design and development of software for digital physical laboratories to increase the level of compliance of behavior of the object with reality and reduce the level of student’s immersion into the virtual environment. One of the tasks for achieving this goal lies in using a synergetic aspect in design and development of software for implementation in the process of teaching natural science disciplines, which allows consolidating virtuality and reality of the surrounding world. In the course of this research, the authors substantiate the synergetic aspect in the development of software for digital laboratories in the context of taking higher school physics. The authors build the main scenario and functional scheme of the software product, which are realized on the high-level C++ language using OpenGL libraries. Software implementation of the digital physical laboratory required preparation of videos with a series of physical experiments, determination of the course of execution of laboratory task, and examples of “returning” from virtual reality.  The developed use case diagram of the actors allowed determining the behavioral pattern of the parties to the development, as well as using the digital physical laboratory in the educational process. Synergetic aspect and possibility of its implementation were tested on the example of digital laboratory work in the context of studying the pendulum motion and fall of bodies. The promising development trend is the design and implementation of software products for determination of synergistic effects in studying the sections of optics and thermodynamics.

DOI: 10.7256/2454-0714.2021.2.35617

Abstract: The subject of this research is the new methods for improving the efficiency of Zabbix monitoring systems for the computational infrastructure of the universal infocommunication commutator, built upon the principle of globally distributed computational complex using the information cloud technologies. The object of this research is the globally distributed computational system of RingCentral corporation (USA), which is based on the technology of hybrid information cloud deployed in over a hundred  data storage and processing centers in all large economic and geographical zones, which provides universal infocommunication services, including video and audio conferences, virtual stationary automated telephone, and organization of call centers. Design and improvement of infocommunication cloud platforms, which provide universal communication services is a complex scientific, technical and economic problem; without its solution it is impossible to create information infrastructure with the service quality indicators that meet the demands of the society. This problem is of particular relevance in the context of worldwide sanitary-epidemiological pandemic of coronavirus, since part of the production processes was switched to remote work, and is executed without physical presence of administrative and technical personnel at the enterprises of national economy. This entailed a decline in the efficiency of networks and quality of customer service in certain infocommunication companies due to excessive nominal loads on the information network, and this, the failure of crucial nodes of user traffic processing.

DOI: 10.7256/2454-0714.2021.2.35214

Abstract: The subject of this research is the frequency planning algorithm for networks with an arbitrary topology of links over radio channels. The algorithm determines the total number of non-overlapping frequency ranges for the entire network and provides the distribution of each frequency range between communication nodes. The algorithm consists of two stages: at the first stage, there is a search and simultaneous distribution of frequency channels, the so-called main frequency range, as a result, only one frequency range is allocated to each node; at the second stage, additional frequency channels are searched for, which can be used by a separate subset of nodes, thus , some nodes can use more than one frequency range, but several at once. The novelty of this research lies in the developed frequency planning algorithm for wireless communication systems with an arbitrary topology of communications over radio channels. The result of the operation of the algorithm for a wireless communication system is the allocation of radio frequencies for communication nodes from the common frequency band allocated for the wireless communication system, in terms of reuse, eliminating the effect of interference. The result for communication nodes is the allocation of a baseband and an additional frequency band, taking into account the topology of the radio network, which can be used by a separate subset that makes wireless communication systems resistant to narrowband random interference.

DOI: 10.7256/2454-0714.2021.2.35507

Abstract: This article reviews the example of using a geometric model of a hypersurface in multidimensional space on the Radishchev blueprint, which reflects interconnection between the four variables in solution of one of the tasks associated with structuring the technological process fulfilled by a welding robot. In structuring technological processes related to welding, it is necessary to solve the optimization task of determining the position of the foundation of welding robot relative to the welded brackets and the axis of the container of cylindrical shape. The welding process requires finding the most optimal welding robot, the geometric model of the kinematic chain of which would move the output link and welding head across all sections of welding seams. As an example, the author reviews the case when the robot is outside the cylindrical container, and welding objects inside and outside. For carrying out the optimization task, the author examines the correlation between the parameters that determine the position of the robot relative to the container, and the minimum possible vertical displacement of the center of the output link based on the graphic optimization model.  The multicomponent system comprised of the four parameters is studied based on the Radishchev blueprint. The author drew the combinations of curves that set the framework of curve lines of the dual level of the hypersurface in the four-dimensional space. For determination of the curves, the author found the combinations of projections of the dots on the Radishchev blueprint. The use of dual level lines on the Radishchev blueprint allowed determining most optimal position of the manipulator mechanism with regards to the cylindrical surface in welding the items for various industrial robots described in this article.

DOI: 10.7256/2454-0714.2021.2.35574

Abstract: Linear surfaces are used in various spheres of human activity. One of the most common techniques of designing linear surfaces is based on the three directing curves. In some cases, one of these directing curves is not set, but rather replaced by some geometric condition imposed on the emerging surfaces, which can in form of a certain point correspondence established between the points of the rest two directing curves. The article reviews the example of designing such surfaces, which in an approximate form would restrict the zone that sets the permissible positions of links of the manipulator mechanism of certain given configuration in realization of permissible instantaneous states. The acquired linear surfaces underlie the algorithm for calculation of configurations, which do not intersect the restricted zone in case of a deadlock situation. The result of this research is the computer simulation of the motions of arm and torso mechanism of the Android robot using the obtained algorithm for calculation of configurations. The simulation of motion demonstrates that the use of linear surfaces in analysis of the relative position of the manipulator and restricted zones in the deadlock situations allows reducing the calculation time by 50-60 percent. Such reduction of calculation time is highly demanded in computer control of the arm and torso motions of the Android robot on a real time scale.