Stanisław Lis

This paper presents the results of laboratory tests on the intensity of mass and heat exchange in a polytunnel, with a focus on the synergy between the polytunnel and a stone accumulator. The subject of study was a standard polytunnel made of double polythene sheathing. In the process of selecting the appropriate working conditions for such a polytunnel, the characteristic operating parameters were modeled and verified. They were related to the process of mass and energy exchange, which takes place in regular controlled-environment agriculture (CEA). Then, experimental tests of a heat accumulator on a fixed stone bed were carried out. The experiments were carried out for various accumulator surfaces ranging from 18.7 m² to 74.8 m², which was measured perpendicularly to the heat medium. To standardize the results obtained, the analysis included the unit area of the accumulator and the unit time of the experiment. In this way, 835 heat and mass exchange events were analyzed, including 437 accumulator charging processes and 398 discharging processes from April to October, which is a standard period of polytunnel use in the Polish climate. During the tests, internal and external parameters of the process were recorded, such as temperature, relative humidity, solar radiation, wind speed and air flow speed in the accumulator system. Based on the parameters, a set of empirical relationships was developed using mathematical modeling. This provided the foundation for calculating heat gains as a result of its storage in a stone accumulator and its discharging process. The research results, including the developed dependencies, not only fill the scientific gap in the field of heat storage, but can also be used in engineering design of polytunnels supported by a heat storage system on a stone bed. In addition, the proposed methodology can be used in the study of other heat accumulators, not only in plant production facilities.

This research covers the process of heat exchange in a cooling microunit equipped with Peltier modules. We put forward that by choosing the control algorithm, not only the control signal quality in such a system is affected but also its energy consumption. Tests were carried out for the following algorithms: relay, parallel PID, serial PID, and PID + DD. An experimental setup was developed that allowed for recording the step response of the investigated plant. Next, the transfer function of the plant was formulated, and a simulation model of the control system was developed using the MatLab^®-Simulink environment. Through computer simulation for a selected system operation procedure (cooling down to three set temperatures and maintaining them for 5000 s), the quality of control signals and the influence on energy use were investigated. The cumulative energy value for each of the algorithms and the cumulative difference in energy consumption between the controllers were calculated. The best results in terms of control quality were obtained for the parallel PID controller. The lowest energy consumption was observed for the relay controller, with the difference compared to other investigated controllers reaching 4.3% and 9.0%, without and with the presence of signal disturbances, respectively.

This research was carried out to compare selected forecasting methods, such as the following: Artificial Neural Networks (ANNs), Classification and Regression Trees (CARTs), Chi-squared Automatic Interaction Detector (CHAID), Fuzzy Logic Toolbox (FUZZY), Multivariant Adaptive Regression Splines (MARSs), Regression Trees (RTs), Rough Set Theory (RST), and Support Regression Trees (SRTs), in the context of determining the temperature of brine from vertical ground heat exchangers used by a heat pump heating system. The subject of the analysis was a public building located in Poland, in a temperate continental climate zone. The results of this study indicate that the models based on Rough Set Theory (RST) and Artificial Neural Networks (ANNs) achieved the highest accuracy in predicting brine temperature, with the choice of the preferred method depending on the input variables used for modeling. Using three independent variables (mean outdoor air temperature, month of the heating season, mean solar irradiance), Rough Set Theory (RST) was one of the best models, for which the evaluation rates were as follows: CV RMSE 21.6%, MAE 0.3 °C, MAPE 14.3%, MBE 3.1%, and R² 0.96. By including an additional variable (brine flow rate), Artificial Neural Networks (ANNs) achieved the most accurate predictions. They had the following evaluation rates: CV RMSE 4.6%, MAE 0.05 °C, MAPE 1.7%, MBE 0.4%, and R² 0.99.

W artykule przedstawiono problematykę funkcjonowania systemu lokalizacji typu LIDAR w zastosowaniach autonomicznych robotów mobilnych klasy AMR. Skupiono się na wykorzystaniu tych robotów jako platform jezdnych do różnych zadań, które wymagają precyzyjnego pozycjonowania. Badania i prace rozwojowe mające na celu stworzenie robota zdolnego do wykonywania prac ogrodniczych, takich jak monitorowanie uprawy (robot inspekcyjny), zbieranie owoców oraz prace pielęgnacyjne, doprowadziły do określenia wymagań konstrukcyjnych i eksploatacyjnych dla platformy jezdnej. W celu spełnienia tych wymagań, zdecydowano się na budowę dedykowanego systemu jezdnego, co zaowocowało przeprowadzeniem badań doświadczalnych w celu oceny dokładności pozycjonowania seryjnie produkowanego robota mobilnego. Wyniki tych badań będą stanowiły punkt odniesienia dla tworzonego prototypu. Wszystkie opisane działania mają na celu osiągnięcie wysokiej precyzji pozycjonowania, która jest kluczowa dla skuteczności wykonywanych zadań. Platformy jezdne robotów AMR zazwyczaj wykorzystują kilka systemów lokalizacyjnych, które współpracują ze sobą. Mogą to być układy kamer wzajemnie zsynchronizowanych lub oparte na triangulacji (pomiarze kątów do trzech obiektów znajdujących się na jednym obrazie). Te metody mogą być uzupełnione przez skanery laserowe, które mierzą odległości od obiektów w bliskim otoczeniu, pozwalając na równoczesny pomiar w szerokim zakresie kątowym. Analiza uzyskanych wyników pozwoliła stwierdzić, że wykorzystanie pojedynczej metody nawigacji w interfejsie robota mobilnego prowadzi do osiągnięcia niskiego stopnia powtarzalności i precyzji dla całego systemu robotycznego

W artykule przedstawiono problematykę funkcjonowania lokalizacji w autonomicznych robotach mobilnych AMR. Lokalizację robota mobilnego przeprowadza się nie na podstawie jednego pomiaru, lecz serii pomiarów wykonywanych najczęściej podczas jazdy. Pojedynczy pomiar dostarcza częściowych danych. Dokładne wyznaczenie położenia robota na podstawie jednego pomiaru z zastosowanie kamery było możliwe przez stereowizję, czyli układ kamer sprzężonych ze sobą, lub przez triangulację, czyli pomiar azymutu do trzech obiektów znajdujących się na jednym zdjęciu. Jak zauważono w przeprowadzonych badaniach, do lokalizacji nadają się płaskie znaczniki z dwoma wyraźnymi pionowymi krawędziami zewnętrznymi. Analiza dokładności lokalizacji na podstawie blisko położonych znaczników znajdujących się na jednym obrazie pokazuje, że mogą wystąpić niekorzystne konfiguracje powodujące bardzo duży błąd lokalizacji. Z kolei dobrą dokładność w triangulacji zawsze uzyskamy, gdy znaczniki są znacznie od siebie kątowe, co wymaga porównania kilku zdjęć lub użycia skanera laserowego, który pozwala na niemal równoczesny pomiar w obszarze o szerokich granicach kątowych.

W artykule przedstawiono metodę analizy systemów sterowania realizowaną na etapie projektowania poprzez modelowanie i symulację komputerową. Należy podkreślić, że koszty związane z usunięciem ewentualnych błędów systemu na tym etapie są najniższe. Na wybranym przykładzie przedstawiono optymalizację algorytmu sterowania i jego nastaw w funkcji niezawodności wyrażającej się w odporności systemu na zakłócenia. W celu przeprowadzenia analizy zbudowano model fizyczny obiektu sterowania. Następnie zarejestrowano charakterystykę skokową obiektu. Na jej podstawie opracowano modele symulacyjne obiektu i układu sterowania, które stanowiły bazę do analizy poprzez symulację komputerową. Wyniki symulacji ostatecznie zweryfikowano na modelu fizycznego obiektu sterowania.

Energy efficiency in the building industry is related to the amount of energy that can be saved through thermal improvement. Therefore, it is important to determine the energy saving potential of the buildings to be thermally upgraded in order to check whether the set targets for the amount of energy saved will be reached after the implementation of corrective measures. In real residential buildings, when starting to make energy calculations, one can often encounter the problem of incomplete architectural documentation and inaccurate data characterizing the object in terms of thermal (thermal resistance of partitions) and usable (number of inhabitants). Therefore, there is a need to search for methods that will be suitable for quick technical analysis of measures taken to improve energy efficiency in existing buildings. The aim of this work was to test the usefulness of the type Takagi-Sugeno fuzzy models of inference model for predicting the energy efficiency of actual residential buildings that have undergone thermal improvement. For the group of 109 buildings a specific set of important variables characterizing the examined objects was identified. The quality of the prediction models developed for various combinations of input variables has been evaluated using, among other things, statistical calibration standards developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The obtained results were compared with other prediction models (based on the same input data sets) using artificial neural networks and rough sets theory.

In this work, the possibility of limiting energy consumption in the manufacturing process of bioethanol to obtain biofuel was analysed. For this purpose, a control algorithm has been optimised while retaining the good quality of the control signals. New in this study is the correlation of the control algorithm not only with the signal’s quality, but also with the energy consumption in such an energy-intensive process as rectification. The rectification process in a periodic production system has been researched. The process was modelled on a test station with the distillation mixture capacity of 25 dm³. For the optimization, the following control algorithms have been applied: relay, PID and PID after modification to I-PD. The simulation was carried out on a transfer function model of the plant that has been verified on a real object, a rectification column. The simulations of energy consumption and control signal’s quality have been carried out in the Matlab^®-Simulink environment after implementing the model of the research subject and control algorithms. In the simulation process, an interference signal with an amplitude of 3% and frequency of 2 mHz was used. The executed analyses of the control signal quality and the influence of the control algorithm on the energy consumption has shown some essential mutual relationships. The lowest energy consumption in the rectification process can be achieved using the I-PD controller—however, the signal quality deteriorates. The energy savings are slightly lower while using the PID controller, but the control signal quality improves significantly. From a practical point of view, in the considered problem the best control solution is the classic PID controller—the obtained energy effect was only slightly lower while retaining the good quality of the control signals.

Praca opisuje problematykę wyznaczania temperatury topliwości popiołu za pomocą indukcyjnego pieca rurowego wykonanego wg autorskiego projektu, realizującego proces spalania (stapiania) próbek popiołu zgodnie z normą z PN-ISO-540:2001. Proces ten...

The article presents the analysis of the automatic control of the bioethanol production process intended for biofuel. It presents the formulated general concept of the system and the method of designing a closed control system based on the iterative prototyping procedure. The modeling and the simulation were carried out in the Matlab®-Simulink environment. The simulation model of the object was developed based on the experimentally registered characteristics. It has been adjusted, i.e. the compatibility of its behavior with the object it reproduces has been confirmed. Based on the tuned model of the object, a control system model was created, which was the basis for computer simulation which enabled the control algorithm parameters to be established. The final verification of the correct operation of the system was performed with the use of hardware simulation. It was based on entering a negative feedback loop of the virtual control system of the real object elements into the loop. The results of the simulation confirmed the correctness of the adopted design.