Категория: АВТОМАТИКА И ИНФОРМАТИКА 2, 2022 г.

Key Words: Generalized predictive controller; disturbance compensation; time-delay; Diophantine equation.

Abstract. The aim of this paper is to design predictive algorithm for control of time-delayed systems with the possibility of measurable disturbance compensation. A new approach to extended Generalized Predictive Control (GPC) has been proposed. Three Diophantine equations are solved non recursively. The cost function and the control law of the GPC are derived. Simulation examples are presented to show results of the design. Two cases are considered – in case of delay between the input and the output of the process, less than the delay, between the disturbance and the output of the process, and in case of delay between the input and the output of the process, greater than the delay between the disturbance and the output of the process. In both cases, comparisons were made between a standard GPC, a compensator with future interference values included in the GPC, a compensator without future interference values included in the GPC and a classic compensator for one case. The results show that the GPC cannot completely eliminate the disturbances, even when the future disturbances values are included in the control. Complete elimination of the disturbances is possible only when the weighting factor, that distributes the energy of the controller, is zero.

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Key Words: Multiple objective optimisation; ethanol production; Saccharomyces sereviciae; general multiple objective optimisation; fuzzy optimisation; fuzzy multiple-objective optimisation.

Abstract. A fuzzy procedure is applied in order to find the optimal feed policy of a fed-batch fermentation process for ethanol production using a Saccharomyces serevicieae. The policy consists in feed flow rate, feed concentration, and fermentation time. In this study biotechnological process is formulated as a general multiple objective optimisation problem. By using an assigned membership function for each of the objectives, the general multiple objective optimisation problem can be converted into a maximizing decision problem. In order to obtain a global solution, a method of fuzzy sets theory is introduced to solve the maximizing decision problem. After this multiple optimisation, the useful product quality is raised and the residual substrate concentration is decreased at the end of the process. Thus, the process productiveness is increased.

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Key Words: Liquid air; energy storage; regenerative steam cycle; feed water; waste heat.

Abstract. The aim of the present study is to evaluate an option of integration of liquid air energy storage (LAES) into regenerative steam turbine cycle. The waste heat from LAES discharge is used for feed water preheating. Thermodynamic analysis shows that the newly proposed hybrid LAES system has a round-trip efficiency of 16% higher than the standalone LAES.

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Key Words: Bragg fiber; bending; losses; Photonic Crystal Fiber; model of deformation.

Abstract. The article analyzes the losses in one type of Photonic Crystal Fiber – Bragg fiber. It is one-dimensional fiber, made as coaxial cylindrical layers. The fiber cladding is a dielectric mirror realized as a multilayer dielectric coating. The paper proposes a method based on geometric optics for the analysis of light propagation losses in a multilayer microstructured fiber with an air core, as a result of tunneling. A model of M-layer fiber with set refractive indices of the dielectric layers is proposed. The angles of incidence and reflection of the boundaries of each two layers of the fiber cladding according to Snelius’ law are calculated. The transverse reflection coefficients of each boundary between two layers for TM and TE polarization are calculated. The electric fields of the reflected and incident beams are calculated. The magnitudes of these vectors are recursively related to each boundary of the previous and next fiber layer. The input power of the light in the first fiber layer for TE and TM polarization is calculated. The losses from light reflection when it passing through all layers of the fiber as a function of the reflection coefficients are calculated. The normalized attenuation is calculated. The characteristic equation for the optical waveguide is decided. The angles of reflection in different modes are calculated. The distance between two consecutive reflections of the beam is calculated as a function of the reflection coefficients for the different polarizations and the reflection angles of the layers for TE and TM polarizations. They determine the reflection coefficient and the phase change when light passes through the whole fiber. The delays of the rays with TE and TM polarization are obtained. The expressions for the chromatic dispersion of the fiber for TE and TM polarization are then derived. A mathematical model of the deformation, presented as a change in the geometry of the fiber in this section as part of a circle is proposed. For this section of the deformed fiber by geometric transformations the connection between the angles of incidence and reflection in the straight and in the round section of the deformed fiber is calculated. The distance between two consecutive reflections from the fiber boundary surface of the rays trajectory is determined by the number of consecutive reflections in the core of the fiber. The reflection losses in TE and TM polarization, which are proportional to the number of beam reflections, are then determined. The phase delays for beams with TE and TM polarization for a fiber of a certain length are determined as the sum of the individual delays in the reflections of the beams. The proposed mathematical model and algorithm for calculating the attenuation of the fiber for different modes of TE and TM polarization, an example of M-layer PCF fiber with air core and alternating dielectric layers with two alternating coefficients and thicknesses is solved, so as to create at the average wavelength of light a phase shift of 900. A MATLAB program has been written. It simulates the attenuation and dispersion of a fiber with set optical parameters. After solving the characteristic equation for this fiber with the introduced parameters, the normalized attenuations for TE and TM polarization are calculated for fiber with and without deformation for different propagating modes. Calculations have been made for fibers with core radius of 20-200 μm for a light wavelength of 1559 nm. The attenuation and chromatic dispersion graphs for TE and TM polarization of several straight and deformed fibers with the same length and different number of layers were plotted. A conclusion about the influence of the core diameter, the bending radius and the number layers of the fiber cladding on the losses of the different propagated modes is made. A comparison of PCF losses and ordinary quartz single-mode fibers was made. In conclusion, the disadvantage of the proposed method is that only the meridional rays of the propagating light are analyzed and the dielectric losses in the fiber cladding are not taken into account. The advantage of the proposed method is the small computational complexity and the correct qualitative result of the PCF analysis with certain parameters. Guidelines for future development are proposed – analysis of the losses of the fiber, taking into account the non-meridional rays in the fiber. The possibilities for using PCF for information transmission and as dispersion compensators in telecommunications are pointed. The possibility of using the method for optimization of certain parameters of PCF of this kind is proposed.

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Key Words: NIR spectroscopy; Partial Least Square method; Radial Basis Functions Neural Networks; moisture content; fat content; pork meat samples.

Abstract. In this study the performance of linear and nonlinear chemometric methods has been investigated and compared. The transmittance spectra of pork meat samples were collected by SW-NIR (short wave near infrared) analyser in the spectral range of 850 nm to 1,050 nm. Partial Least Square (PLS1) method and Radial Basis Functions Neural Networks (RBF NN) were chosen for chemometric analysis of that samples for determination of moisture and fat content. The reason for using RBF ANN is significant nonlinearity which is exhibited between the spectra and the fat and moisture content. PLS1 and RBF NN with different architecture have been combined with different pre-processing techniques such as first derivative (D1), standard normal variate (SNV), multiplicative signal correction (MSC) and the combinations of MSC and SNV with first derivative. It was found that optimal pre-processing was MSC for moisture, and the combination of D1and SNV for fat. When PLS1 was used, results showed reduction of RMSEP and REP using MSC with 15 and 13% for moisture determination. In case of PLS1 fat determination considerable reduction of RMSEP and REP was observed using a combination of D1 and SNV with 48 and 47%. Compared to PLS1 regression with suitable preprocessing, RBF ANN showed better results: reduction of RMSEP and REP using a combination of D1 and SNV with 48% for moisture, and reduction using a combination of D1 and SNV with 59% for fat determination. These improvements together with the facility of SW-NIR technology to be implemented in the process engineering made it ideal for the meat industry.

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Key Words: Internet of Things; Wireless Sensor Network; smart home; integration; voice assistant.

Abstract. An integrated Smart Home system for monitoring and management of the elements of the working environment or at home in Home Assistant platform and is integrated with a voice assistant (Google Assistant) has been developed. The structure of the Smart Home (SH) system is based on the concept of the Internet of Things (IoT), which includes connectivity of devices and actuators, as well as the presence of Wireless Sensor Network (WSN). The main functions in each SH depend strongly on the requirements, way of live, special health issues, availability of pets and appliances etc. of the household members, as well as the home/house architecture, location etc. The developed integrated system structure consists of the following main modules: connected devices, measuring (sensor) module, processing module, visualization module (interface), communication module (voice communication). The system allows monitoring and control of various parameters of the environment, determination of geolocation, tracking the state of the connected devices, provides ascertainment of conditions or constraints during the implementation of logical algorithms or actions, etc. The developed integrated system solves the problem of using various interface applications, communication protocols and standards by integration of all its elements in one Application Programming Interface (API) and simultaneously the system is expanding its scope through its integration with a voice assistant (Google Assistant). In the developed integrated system solutions with pre-set functions, default functions and user selection functions are implemented. Also, specially designed by the author (G. Kolev), made and tested IoT boards for stepper motor control, RGB LED strip, as well as IoT board for control of small relays for concealed mounting are applied. The system operation rules can be set by the user (directly or in time) or depending on the values obtained from the sensors (Sensor-based Linked Open Rules). The developed SH system gives also the possibility for building actions according to the geolocation of each of the devices (users) via the GPS system of the phone. Elements, connected with the energy utilization (consumption) efficiency – electricity, water and heat consumption efficiency are also considered. The optimization of the consumption is directly connected with cost savings which adds an additional benefit to the undeniable advantages of the Smart Home system development. The process of development of integrated remote-control Smart Home systems can continue without limitation in time as far as the imagination of the designer and/or the users reaches.

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На 31 май 2022 г. Съюзът по автоматика и информатика „Джон Атанасов“ (САИ) проведе Общо събрание, на което Управителният съвет направи отчет за периода 2017-2021 г., бяха набелязани насоки за следващия отчетен период 2022-2025 г. и бяха проведени избори за нови ръководни органи на САИ.

В отчетния доклад беше акцентирано върху големия брой проведени престижни международни конференции и симпозиуми като: Advances in Neural Networks and Applications (ANNA), 15-17 септември 2018 г., Варна; 19-а IFAC конференция „Technology, Culture and International Stability” (TECIS’19)…

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Управителен съвет
1. Ангел Смрикаров
2. Валери Андреев
3. Ваня Стойкова
4. Валери Младенов
5. Васил Сгурев
6. Веселин Акиванов
7. Владимир Йоцов
8. Драгомир Добруджалиев
9. Емил Николов
10. Иван Куртев
11. Камен Спасов
12. Камен Перев
13. Кирил Алексиев
14. Кирил Боянов
15. Коста Бошнаков
16. Красимира Стоилова
17. Любка Дуковска
18. Минчо Хаджийски
19. Михаил Петров
20. Никола Николов
21. Никола Петков
22. Петко Русков
23. Пламен Ангелов
24. Румен Трифонов
25. Станимир Йорданов
26. Таня Пенчева
27. Христо Вълчанов
28. Цветелина Георгиева
29. Чавдар Дамянов
30. Ясен Горбунов

Повече

1. Увеличаване на членския състав (физически и юридически лица) и преди всичко привличане на млади специалисти, на колеги от бизнеса и на работещи в чужбина. Укрепване и разширяване на организационните структури и развитие на дейността им.
2. Продължаване на усвояването и широко прилагане на информационните технологии в съюзния живот в посока на обобщение на най-актуалните научно-технически предизвикателства в областта на дигитализацията и иновациите в духа на Индустрия 4.0.

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