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- MakaleAçık Erişim2024Scopus SJRQ3Machine learning driven optimization and parameter selection of multi-surface HTS Maglev
Ozkat, Erkan Caner; Abdioglu, Murat; Ozturk, U. Kemal
This research aims to tackle the challenges posed by precise force measurement for high temperature superconducting (HTS) Maglev systems, including mechanical constraints, step motor limitations, and sensor resolutions. For this aim, six machine learning (ML) models namely Support Vector Machine (SVM), Gaussian Process Regression (GPR), Extreme Gradient Boosting (XGB), Long Short-Term Memory (LSTM), Extreme Machine Learning (EML), and Convolutional Neural Network (CNN) were developed to predict levitation force (Fz) and lateral force (Fx) based on process parameters including permanent magnet width (PMW), field cooling height (FCH), the movement in the z-axis (vertical distance), and the movement in the x-axis (lateral distance). Among six ML models, CNN emerged as the most accurate model, demonstrating smaller root mean square deviation (RMSD) without compromising correlation coefficients. Furthermore, an innovative process window approach was introduced to select process parameters that simultaneously meet the minimum value of Fz and maximum value of Fx, named β1 and β2, set at 90 N and 0 N, respectively. Within this window, PMW of 30 mm and z values less than 10 mm were found to be consistent for all FCH and x values. The novelty of this study is to formulate the optimisation problem in HTS Maglev using the developed ML model by addressing two specific objectives one of which focuses on maximizing Fz while ensuring Fx remains within a defined tolerance (β3), representing the minimum allowable ratio of the levitation force to the total force, and the second problem aims to maximize Fz while obtaining zero Fx. The optimum PMW, FCH, x, and z values were obtained at 30 mm, 30 mm, 4 mm and 5 mm, corresponding to Fz and Fx values of 224.2 N and -53.8 N for option 1. As for option 2, the process parameters were obtained as 28.6 mm, 25.9 mm, 0 mm, and 5 mm, corresponding to Fz and Fx values of 194.2 N and 0 N. It was obtained both experimentally and by the optimization that Fz reaches close its maximum as the Fx gains attractive character. Hence, it is expected that the outcomes of this study will significantly benefit the design of HTS Maglev systems and find valuable applications across various transportation engineering projects.
AtıfScopus21WoS18
İncele - MakaleAçık Erişim2021Scopus SJRQ3Comparing of the Magnetic Force Parameters of Superconducting Maglev System Using Horizontal and Vertical PMG Geometry in Multi-Surface HTS-PMG Arrangement
Ozturk, Kemal; Savaskan, Burcu; Abdioglu, Murat; Cansiz, Ahmet; Dilek, Durukan Burak; Karaahmet, Zekeriya
In this study, a detailed static and dynamic experimental studies were carried out in different cooling heights (CH) by using two different multi-surface HTS-PMG arrangements with horizontal (MS-H) and vertical (MS-V) geometries to determine the optimum magnetic force, static stiffness, dynamic response, and dynamic stiffness parameters of superconducting Maglev system. The maximum levitation force values (in CH = 25 mm) were obtained as 202 N and 84 N, respectively, with horizontal and vertical geometry HTS-PMG arrangements, while the maximum guidance force values (in CH = 5 mm) were obtained as −58 N and −22 N, respectively. Also, the vertical static (in CH = 25 mm) and dynamic stiffness (in CH = 5 mm) values were determined as 33.8 N/mm and 37.8 N/mm, respectively, for MS-H and 12.3 N/mm and 25.1 N/mm, respectively, for MS-V arrangements. The bigger levitation force, guidance force, and both static and dynamic magnetic stiffness values of MS-H arrangement with horizontal geometry than that of MS-V arrangement with vertical geometry indicate that the horizontal HTS-PMG geometry is more suitable for practical Maglev applications in terms of loading capacity and movement stability.
AtıfScopus5WoS4OpenAlex4İncele