Preview

«System analysis and applied information science»

Advanced search
No 1 (2021)
View or download the full issue PDF (Russian)
https://doi.org/10.21122/2309-4923-2021-1

Management of technical objects

4-11 2107
Abstract

An innovative project to create a prototype of a multifunctional mobile automated stringed robotic complex is announced. A distinctive feature of the project is the mobility in relocation and the maximum use of artificial intelligence to solve problems of ensuring the security of a protected object or territory.

12-20 638
Abstract

This paper discusses the problem of determining a kinematics (in terms of transfer function, as far as possible) of parameters of the motion of an aircraft expressed in the curvilinear coordinate system and control accelerations expressed in a rectangular coordinate system. Examples of curvilinear coordinate systems using in practice can be polar, biangular, two-center bipolar, elliptic, parabolic cylindrical, spherical, ellipsoidal, coordinate systems. A technique for obtaining a kinematic link for the control problem of an unmanned aerial vehicle in the elliptic coordinate system was described. It allowed to obtain simpler view of the kinematic link which could provide navigation an aircraft along the hyperbola deriving from the time difference of arrival navigation system. It can. As a result, it is possible to reduce the number of the navigation radio beacons.

21-28 755
Abstract

The problem of the stage-by-stage synthesis of the mathematical model of the autopilot of an unmanned aerial vehicle (UAV) is considered. At the first stage, an analytical synthesis of the control acceleration applied to the center of mass of the UAV is performed to form a specified trajectory of its flight. On the basis of the results received at the first stage, at the subsequent stages, the problem of synthesizing a mathematical model of the UAV autopilot is solved with the specified requirements for ensuring the stability and dynamic accuracy of UAV control. Under actual assumptions about the corresponding nature of changes in the trajectory parameters and variables that characterize the motion of the UAV in space, the use of a linear mathematical model of the evolution of the state vector of the UAV and its control system is substantiated. When synthesizing a mathematical model of the UAV autopilot, the method of modal control of the system was used for a specified mathematical model of the object. For a specified model of motion and aerodynamic characteristics of the UAV, the law of deviation of the control steering surface is analytically received, which depends on the parameters of the translational and rotational movement of the UAV. Computer simulation of the analytically received results of control synthesis for the specified characteristics of UAVs and specific using conditions was carried out, which clearly showed the efficiency and prospects of using this approach for the synthesis of control systems for UAVs of various purposes and design.

29-37 802
Abstract

Use of CAN BUS for data transmission in Real-Time mode with Simulink on control objects is considered (6-DoF a platform).

It is revealed that software of CAN_ API.dll adapters, created in the Microsoft Visual Studio (MVS) does not work with TDM-GCC-64 Matlab/Simulink because of different approach in names of the dll functions according to the standard C ++ 11/17. Recompile by the developer of the adapter of its software (dll) in the TDM-GCC-64 environment under Windows is required.

It is established that CAN BUS considerably reduces modeling speed by 4.5 times. The way of information compression and fall forward of exchange twice due to byte-by-byte entering of two float values in the data field is offered. Use of identical values of identifiers is applied to two cylinders 6-DoF of a platform and the subsequent their division in the program microcontrollers of cylinders.

For implementation of a Real-Time mode in addition to compression it is offered to transfer data with the smaller frequency (quantization) by what a modeling clock period. It was considered that 6-DoF platforms reproduce frequency band to 10–12 Hz. The program of transfer/data exchange with Simulink on stand control devices with quantization is developed. Influence of parameter of quantization for the period of modeling is investigated. It is established that the Real-Time mode of modeling is provided in the range of parameters of quantization (chc=1/350–1/1000). Frequency of exchange with 6 cylinders at the same time corresponds to 230, 150 Hz.

Data processing and decision–making

39-44 758
Abstract

Belarusian state University of Informatics and Radioelectronics, Minsk, Republic of Belarus

The quality of milk is evaluated by a number of control points, which include a number of indicators, such as fat content, protein, lactose, density, etc. It is proposed to use the Internet of things (IoT) technology to control the quality of milk from distributed dairy farms. A multi-agent model of IoT network and the structure of such an IoT network for monitoring the quality of milk from different farms is presented. The model is represented by a variety of agents: milk analyzers, converter, storage of quality indicators, their processing, decision-making, monitoring of milk quality indicators.

The structure of the IoT network includes milk analyzers, gateways-converters, a cloud platform, and mobile devices. The cloud platform rents a server that hosts knowledge and data bases, special software (solver) for processing and making decisions on milk quality, and a farm website. The database of the cloud structure server stores milk quality characteristics, and the knowledge base stores the rules for processing them. The solver outputs deviations from the current milk quality indicators from the standards. The site is used for communication of specialists in milk quality control. Monitoring of milk quality characteristics is implemented from mobile devices of specialists with access to the site components.

The 4th generation LTE network using NB-IoT technology was chosen as the network for transmitting information from dairy farms to the cloud. The review of milk analyzers of both domestic and foreign companies is carried out. A gateway solution for querying milk analyzers and transmitting parameters to the cloud infrastructure is presented. Popular cloud platforms for building a network of IoT are presented.

45-52 852
Abstract

Given article is devoted features of the decision of a problem of integer nonlinear programming, by means of developed neural network method and algorithm of nonlinear optimization of means «decision Search» tabular processor Microsoft Excel. In offered neural network method the task in view decision is made by means of a recurrent neural network (RNN) matrix architecture with m neurons in each line and n neurons in each column. All neurons such network are connected with each other by communications, and the signal from an exit neuron can move on its input. Neural network method is characterized by that on inputs mentioned RNN the entrance vector of values of parameters of optimized nonlinear criterion function of a problem of distribution of a non-uniform resource moves, calculation of values of weight factors connected among themselves neurons is carried out and signal RNN is formed. This signal by means of nonlinear function will be transformed to the discrete target signal characterizing values quasi-optimal of the decision of the mentioned problem which size changes from 0 to 1. The estimation of efficiency of the decision of a considered problem was carried out at its various values of an indicator of efficiency on the basis of developed imitating model RNN. As indicators of efficiency of application offered neural network method were used – an average relative error and time of the decision of a problem. The value received by means of algorithm of nonlinear optimization of means was accepted to the exact decision «decision Search» tabular processor Microsoft Excel. The analysis of the received results of the experimental researches, offered neural network method, has allowed to make the conclusion that in comparison with an existing method of nonlinear optimization of tabular processor Microsoft Excel use offered neural network method allows essentially (in 9,4 times) to lower time of the decision of a problem dimension 10 × 8 (m × n) and thus to provide accuracy of its decision not less than 99,8 %.

53-61 645
Abstract

Problem of estimation of variated frequency of components of polyharmonic signals has been arose. Three-dimensional time-frequency representation of signals is usually used to resolve this problem. But simple and reliable method of instantaneous frequency tracking is needed. Frequency tracking method based on estimation of shifts of peaks of spectrogram has been proposed in this paper. It is assumed that shift of spectral peaks of components of signal is proportional to variation of fundamental frequency. Logarithmic scaling of time-frequency representation is used to make spectral peaks equidistant. Temporal dependence of shift of spectral maximums is obtained using correlation of windowed spectrum at the first frame and spectrum of signal in the current window. Then obtained track is translated in linear scale. Proposed method does not estimate values of instantaneous frequency or central frequency of signal component but estimates its variation. Advantage of the method is that it can estimate frequency track even if range of frequency variation and its central value are known roughly or unknown at all. Multiple components do not interfere to estimate fundamental frequency variation. Reduction of bandwidth is recommended to increase accuracy of frequency track estimation, but analysis of time-frequency representation containing a few components is also possible. Dependency of performance of analysis of synthetic signals using the method on various signal to noise ratios under different conditions was estimated. Applicability of the method for vibrational diagnosing of rotary equipment was checked out using spectral interference method.

62-69 2118
Abstract

The aim of the work is to limit excessive thinning and increase the resistance to contour noise of skeletons resulted from arbitrary binary image shape while maintaining a high skeletonization rate. The skeleton is a set of thin lines, the relative position, the size and shape, which conveys information of size, shape and orientation in space of the corresponding homogeneous region of the image. To ensure resistance to contour noise, skeletonization algorithms are built on the basis of several steps. Zhang-Suen algorithm is widely known by high-quality skeletons and average performance, which disadvantages are the blurring of diagonal lines with a thickness of 2 pixels and the totally disappear patterns of 2x2 pixels. To overcome them, a mathematical model that compensates the Zhang-Suen algorithm has proposed in this paper, along with a producing mask and two logical conditions for evaluating its elements.

Information technologies in education

71-75 2008
Abstract

The modern stage of development of CAD-systems is characterized by a significant expansion of the scope of their use. An interesting direction for improving CAD systems is their integration with CAM systems. One of the main tasks solved by CAM systems is the development of control programs for CNC machines. Many software developers for automation of design and technological preparation of production have already equipped their systems with appropriate modules. These circumstances pose an urgent task for higher educational institutions to introduce the study of integrated CAD/CAM systems into the educational process of training design engineers. In this case, the emphasis should be placed on the practical mastery of the skills of developing control programs using a 3D-model of the manufactured part. The stages of preparation for the implementation of the system are described, starting with the analysis of the market of necessary software products and ending with the adaptation of the licensed system to the conditions of use in the educational process of the university. A link is given to the description of the methodology used in the assessment of automated systems at the stage preceding the tender for their purchase. It is emphasized that the study of the possibility of using a CAD/CAM system in the preparation of design engineers was carried out by students during the course and diploma projects in the discipline “Automated systems for technological preparation of production”. The methodology for designing control programs used by students is given, and the results obtained are assessed.



Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


ISSN 2309-4923 (Print)
ISSN 2414-0481 (Online)