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Previous Version of
the TU-Sofia Proceedings'
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March 2024
Table of Contents
| Proposal and Study of Model Predictive Control System for Automated Greenhouse Management |
| Ilker Yahov, Roumen Trifonov |
Abstract: This research explores the possibilities for application of Model Predictive Control (MPC) in greenhouse management to enhance climate precision and energy efficiency. Greenhouses play a crucial role in global food production, but maintaining ideal growing conditions is resource intensive. The study proposes an MPC strategy, empirically validated in a dynamic greenhouse environment, demonstrating its superiority in minimizing energy costs and achieving optimal resource consumption. Emphasizing alignment with Industry 4.0 principles, the research integrates MPC into modern agricultural practices, contributing to low energy consumption and reduced water and pesticide use. An experimental model simulates a commercial growth chamber, providing a platform for comprehensive testing under various scenarios. Despite inherent limitations, the model allows rigorous evaluation of different strategies, highlighting improved temperature control and energy efficiency. The study outlines innovative principles, emphasizing advantages such as intuitiveness, applicability to diverse processes, and robust constraint handling. Challenges, including accurate process modelling, are acknowledged. The findings promise to help revolutionizing greenhouse management, advancing the industry toward a more sustainable and technologically advanced future. Keywords: Energy Efficiency, Climate Optimization, Model Predictive Control (MPC), Greenhouse Management |
| DOI: 10.47978/TUS.2024.74.01.001 |
| Enhancing Tower Crane Stability through Mast Bracing and Finite Element Analysis |
| Chavdar Georgiev |
Abstract: Tower cranes are indispensable assets in modern construction projects, facilitating heavy lifting at towering heights exceeding 100 meters. However, their slender and lightweight design renders them susceptible to buckling failures, particularly in the mast and boom structures, raising concerns about static and dynamic stability. This paper presents a comprehensive finite element analysis methodology to assess buckling behavior in tower cranes, accounting for both structural and mechanical complexities. Through linear buckling analysis, critical buckling modes and load magnitudes are identified, while a comparative assessment is conducted between configurations with and without bracings. The results underscore the mast's compromised stability due to its extended length, leading to diminished stiffness. Conversely, tower cranes equipped with additional bracings demonstrate improved stability and operational safety. Furthermore, numerical simulation is employed to evaluate the efficacy of mast bracing in enhancing tower crane stability. This study emphasizes the pivotal role of mast bracing in augmenting the overall stiffness and stability of tower cranes, particularly in dynamic operating environments. It provides valuable insights into optimizing tower crane design and mitigating risks associated with crane operations in high-rise construction settings. Keywords: Tower cranes, Mast bracing, Finite Element Analysis, Stability, Buckling analysis, High-rise construction |
| DOI: 10.47978/TUS.2024.74.01.002 |
| Surface Roughness of Hardened Steel Parts Machined with Round Inserts Face Mills |
| Larysa Ye. Hlembotska, Lubomir V. Dimitrov, Valerii A. Kyrylovych, Oleksandr L. Melnyk, Natalia O. Balytska |
Abstract: When machining hardened steels with multi-blade tools, problems arise that have a negative impact on the surface quality and process productivity. This is especially true when finishing flat workpiece surfaces by face milling. The surface roughness, as one of the geometric indicators of surface quality, primarily depends on the shape and geometric parameters of the cutting edges of the mill. The expediency of using round inserts of face mills for machining parts made of hardened steels has been substantiated. New results concerning the quality of machined surfaces were obtained when machining with a face mill with a flat front surface of round inserts and a face mill with a cylindrical front surface of inserts. The influence of cutting modes on the machined surface roughness has been studied, which made it possible to recommend optimal cutting modes for face mills with round inserts according to the criterion of minimum surface roughness. It was found that at the maximum cutting modes, a face mill with cylindrical front surfaces of inserts produced a lower machined surface roughness than a face mill with flat front surfaces of round inserts. At the same time, when machining with a face milling cutter with cylindrical insert fronts, by 1.27 times increase in productivity is achieved. Keywords: Cylindrical front surface, Face milling, Hardened steels, Process productivity, Surface roughness |
| DOI: 10.47978/TUS.2024.74.01.003 |
Last changed on 13.04.2024, 13:54:05