류경돈 Kyung-don Ryu

DOI: JANT Vol.28(No.4) 379-385, 2024

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INS(inertial navigation system) aligns itself using gravity and Earth’s rotational rate from accelerometers and gyro sensors when stationary. Typically, ZUPT(zero velocity update), which is based on a linear error model Kalman filter, is used when it is stationary. However, such algorithms assume stationary conditions, leading to increased alignment errors or filter divergence during maritime mooring due to wave-induced motion. This paper designs a mooring alignment algorithm for maritime platforms using a Kalman filter, which uses large heading angle error model and an initial position correction technique. And it is validated by simulation. Furthermore, it is confirmed that applying this to a rotational INS dramatically improves performance through the principle of bias cancellation.

노치성 Chi-sung Roh , 김다니엘 Daniel Kim

DOI: JANT Vol.28(No.4) 386-392, 2024

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This paper constructs a precise dynamics model using flightlab, a specialized program for rotor modeling and performance analysis, to simulate urban air mobility (UAM). flightlab is well-suited for detailed modeling of UAM, particularly requiring detailed aerodynamic characteristics under high-altitude and urban wind conditions. The study focuses on implementing and analyzing a lift-cruise UAM model with distributed propulsion using flightlab. The lift-cruise model integrates motors for vertical take-off and fixed-wing flight. Given the limited specific examples of such UAM models in flightlab and challenges in evaluating with conventional fixed-wing or drone models, this research implements and verifies the lift-cruise model using matlab, comparing its performance against flightlab results to validate the modeling approach. This research aims to explore the potential of flightlab for detailed UAM modeling and contribute to technological advancements in future urban transportation.

최경철 Kyung-chul Choi , 김지훈 Ji-hun Kim , 최낙민 Nak-min Choi , 백경훈 Gyong-hoon Baek

DOI: JANT Vol.28(No.4) 393-399, 2024

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The digital map computer for advanced air vehicles (AAV) must be high-performance, lightweight, portable, and modular. It should receive data on terrain, weather, and obstacles from external modules to display digital maps accurately. This necessitates robust communication capabilities with external devices via an Ethernet interface and the ability to output digital map visuals clearly through an high-defintion multimedia Interface (HDMI) or digital visual interface (DVI) interface. This paper presents the design of both hardware and software architecture that fulfills these critical requirements for an AAV digital map system. Additionally, it establishes the minimum specifications needed and verifies the suitability of the designed digital map computer through rigorous performance measurements and testing. By ensuring these standards, the digital map computer can reliably support the complex navigational needs of AAV, enhancing operational efficiency and safety.

우지원 Ji Won Woo , 김양곤 Yang Gon Kim , 안정우 Jung Woo An , 박상윤 Sang Yun Park , 남경래 Gyeong Rae Nam

DOI: JANT Vol.28(No.4) 400-407, 2024

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The role of unmanned aerial vehicles (UAVs) in modern warfare is increasingly significant, making their capacity for autonomous missions essential. Accordingly, autonomous target detection/identification based on captured images is crucial, yet the effectiveness of AI models depends on image sharpness. Therefore, this study describes how to determine the field of view (FOV) of the camera and the flight position of the UAV considering the required spatial resolution. Firstly, the calculation of the size of the acquisition area is discussed in relation to the relative position of the UAV and the FOV of the camera. Through this, this paper first calculates the area that can satisfy the spatial resolution and then calculates the relative position of the UAV and the FOV of the camera that can satisfy it. Furthermore, this paper propose a method for calculating the effective range of the UAV's position that can satisfy the required spatial resolution, centred on the coordinate to be photographed. This is then processed into a tabular format, which can be used for mission planning.

심영민 Yeong-min Sim , 황예승 Ye-seung Hwang , 전재욱 Jae-wook Chun , 이민재 Min-jae Lee , 문우춘 Woo-choon Moon

DOI: JANT Vol.28(No.4) 408-419, 2024

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Currently, the airport is expected to improve flight punctuality and operational efficiency after establishing A-CDM, which provides a foundation for mutual cooperation based on an information sharing system among stakeholders. An important element of the A-CDM is to share time information generated by each stakeholder from the arrival of an aircraft to ground operations and departure of the aircraft, thereby supporting timely arrival and departure of aircraft and improving the efficiency and punctuality of airport operations. In the UAM system, a vertiport that plays a role similar to an airport also needs to establish a system to share time information generated by each stakeholder for efficient operation of limited resources. In this regard, a method is needed to identify time information that needs to be shared by each stakeholder and apply technology to share it. In this paper, we propose an application method for system technology that classifies and mutually shares time information generated by stakeholders related to Vertiport operation according to data characteristics.

강광천 Kwang-chun Kang , 신수영 Su-young Shin , 윤형근 Hyoung-keun Yoon , 윤태경 Tae-gyeong Yun

DOI: JANT Vol.28(No.4) 420-427, 2024

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This study proposes a method for utilizing flight and flow - information for a collaborative environment (FF-ICE) for flight plan management based system wide information management (SWIM) technology for the safe and efficient operation of urban air mobility (UAM). SWIM provides a standardized infrastructure for air traffic data, enabling seamless information exchange among various stakeholders. This study purposed flight plan procedures for UAM operation regarding submitting preliminary and filed flight plans, validation and operational evaluation processes, state management, and the roles of each stakeholder. The system developed through the SWIM infrastructure for low-density urban air mobility traffic management. The study are expected to significantly enhance the safety and efficiency of UAM operations through strategic flight plan management methods.

김준성 Joon-sung Kim , 심재용 Jae-yong Sim , 장수림 Su-lim Jang , 임승찬 Seung-chan Lim , 정윤호 Yunho Jung

DOI: JANT Vol.28(No.4) 428-435, 2024

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In this paper, a human activity regeneration (HAR) system based on multiple input multiple output frequency modulation continuous wave (MIMO FMCW) radar was designed and implemented. Using point cloud data from MIMO radar sensors has advantages in terms of privacy, safety, and accuracy. For the implementation of the HAR system, a customized neural network based on PointPillars and depthwise separate convolutional neural network (DS-CNN) was developed. By processing high-resolution point cloud data through a lightweight network, high accuracy and efficiency were achieved. As a result, the accuracy of 98.27% and the computational complexity of 11.27M multiply-accumulates (Macs) were achieved. In addition, the developed neural network model was implemented on Raspberry-Pi embedded system and it was confirmed that point cloud data can be processed at a speed of up to 8 fps.

김도현 Do-hyun Kim , 장효석 Hyo-seok Chang

DOI: JANT Vol.28(No.4) 436-441, 2024

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Urban air mobility (UAM) is an innovative air traffic management system that utilizes electric vertical take off and landing aircraft(eVTOL) to transport passengers and cargo in urban areas. The corridor can be defined as the airspace that the vehicle operates in and must be collaboratively managed. For the stable operation of UAM, it is essential to have strategic separation and a collaborative decision-making(CDM) system for cooperation and coordination among stakeholders. This study examines the application of time-based milestones from traditional air traffic flow management to the UAM system to ensure safe traffic volume and optimize air traffic flow. For traffic flow management, the milestone time information is categorized into a total of 13 key milestone time indicators based on the UAM movement status, and the sharing entities providing each time indicator and the flow of milestones are defined. Emphasizing the need for a CDM to balance UAM traffic and capacity, sharing and managing milestone information among stakeholders is expected to improve UAM aircraft departure flow and enhance operational efficiency.

김경욱 Kyungwook Kim , 윤형근 Hyoung-keun Yoon

DOI: JANT Vol.28(No.4) 442-449, 2024

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In this paper, we aim to propose a comprehensive framework for cyber threat analysis of urban air mobility (UAM) or advanced air mobility (AAM) communications, navigation, surveillance, and information system infrastructure. By examining potential vulnerabilities and threat vectors, we seek to enhance the security and resilience of UAM infrastructure. We conduct a detailed cyber threat analysis to identify and categorize various types of cyber threats, assess their impact on the CNSi systems, and evaluate the vulnerabilities within these systems that may be exploited by such threats. This analysis will provide valuable insights for stakeholders involved in the deployment and operation of UAM systems, ultimately contributing to the safe and efficient integration of urban air transportation.

윤태경 Tae Gyeong Yun , 오수환 Soohwan Oh

DOI: JANT Vol.28(No.4) 450-458, 2024

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Urban air mobility (UAM) shows great promise for commercialization, yet the technical foundations for ensuring safety in large-scale operations remain a challenge. The purpose of this paper was to analyze current air traffic conflict management techniques in order to develop strategies for implementing strategic conflict management within UAM traffic management systems. We found that UAM conflict management can benefit from demand and capacity balancing techniques, and a system-wide approach is essential. Specifically, the use of data sharing and probabilistic methods is essential for addressing flight time uncertainty and large-scale UAM operations effectively.

이영서 Young Seo Lee , 김지용 Ji Yong Kim , 김덕곤 Duk Gon Kim , 백경훈 Gyong Hoon Baek

DOI: JANT Vol.28(No.4) 459-465, 2024

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The flight control computer applied to manned/unmanned aircraft is one of the key components directly connected to the control of the aircraft, and is generally designed with a redundant architecture so that essential functions for flight can be maintained even if a failure occurs in a single channel. The operational flight program loaded on these redundant flight control computers should be designed considering a time synchronization between channels, input data selection methods from redundant sensors, and fault detection/isolation methods for channels. In this paper, we propose a redundancy management method applied to triplex compact flight control computers for advanced air vehicle. The proposed redundancy management method includes a synchronization algorithm between triplex channels, an input data voting method from sensors, a bus control right selection method for control command output, and a fault detection/isolation method for channels.

배동환 Dong-hwan Bae , 윤효중 Hyo-jung Yoon

DOI: JANT Vol.28(No.4) 466-471, 2024

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Recently, the Machine Learning based Artificial Intelligence has introduced in aviation field. In most cases, safety assurance of aviation software is achieved by applying RTCA DO-178C or DO-278A or similar standards. These standards were developed for and are well-suited to software that has inherent deterministic properties and explainability. Considering the characteristics of AI software based on ML, it is not feasible to assure the integrity of those new aviation systems using traditional software assurance standards mentioned above. In this paper, we research the certification framework that is newly suggested by EASA to deal with the aviation system including ML AI functions, and discuss what should the Korean authority and related industries prepare to cope with this issue.

김정훈 Jung-hoon Kim , 조희덕 Hee-duk Cho , 최선미 Seon-mi Choi

DOI: JANT Vol.28(No.4) 472-479, 2024

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Half of the world's total population lives in cities, continuous urbanization is progressing, and the urban population is expected to exceed two-thirds of the total population by 2050. To resolve this phenomenon, the Korean government is focusing on building a new urban air mobility (UAM) industrial ecosystem. Airlines are also part of the UAM industry ecosystem and are preparing to improve efficiency in safe operations, passenger safety, aircraft operation efficiency, and punctuality. This study performs demand forecasting using time series data on the number of daily passengers on Korean Air's Gimpo to Jeju route from 2019 to 2023. For this purpose, statistical and machine learning models such as SARIMA, Prophet, CatBoost, and Random Forest are applied. Methods for effectively capturing passenger demand patterns were evaluated through various models, and the machine learning-based Random Forest model showed the best prediction results. The research results will present an optimal model for accurate demand forecasting in the aviation industry and provide basic information needed for operational planning and resource allocation.

박세은 Se-eun Park , 박선민 Sun-min Park , 김휘양 Hui-yang Kim

DOI: JANT Vol.28(No.4) 480-489, 2024

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The Ministry of Land, Infrastructure and Transport duplicated a section of ATS Route Y579 connecting Jeju and Busan in 2022 to enhance aviation safety and operational efficiency. Before duplication, an offset procedure was applied to separate aircraft flying in opposite direction by deviating them to the right of their intended flight paths. However, on December 1, 2022, this offset procedure was abolished and replaced with two parallel route, Y571(towards Busan) and Y572(towards Jeju), to improve safety and efficiency. The duplication of ATS Routes has significant implications in various aspects. This study analyzes the safety of the newly established ATS Routes and compares their safety with the previously applied offset procedure to evaluate the effectiveness of the duplication. Additionally, it presents the significance from the perspective of airspace operation. A safety assessment has conducted using a modified version of the Reich CRM (collision risk model). The analysis results confirms that the level of safety improves after the duplication and that there were benefits in terms of airspace utilization.

황준혁 Jun-hyeok Hwang , 김규왕 Kyu-wang Kim

DOI: JANT Vol.28(No.4) 490-496, 2024

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Flight education is an essential element in ensuring the development and safety of the aviation industry. Korea's aviation industry has grown rapidly, and the need for professional flight training is increasing accordingly. The purpose of this paper is to analyze the current status of Korea's flight education environment and seek ways to improve it. In addition, we examined whether the operation method and educational environment of Korea's professional pilot training institutes were structured appropriately for student education, and conducted a survey on the flight education infrastructure targeting trainees, instructors, and aviation workers receiving training at Korea's pilot training institutes. Through the survey, we investigated the necessity and urgency of improving the infrastructure for domestic flight education and drew meaningful conclusions.

강남선 Nam-seon Kang , 이창식 Chang-sik Lee , 유성상 Seong-sang Yu , 이종민 Jong-min Lee , 손금준 Gum-jun Son

DOI: JANT Vol.28(No.4) 497-506, 2024

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In this study, we proposed security information and event management for ship as a technology to respond to maritime cybersecurity regulations and evolving cyber threats. We analyze the main technologies of network management system and security information and event management, which are representative technologies for responding to ship cyber security, and propose SIEM for ships based on this. Optimized for ships based on the International Maritime Organization's Maritime Cyber Threat Management Guidelines, IACS UR E26, 27, etc. Derive the main functions of the SIEM for ship, linkage and normalization plan for the ship's heterogeneous equipment, ship's cyber threat and ship detection policy to identify ship's cyber security threats, and ship's operating environment and operating personnel.

한삼승 Sam-seung Han , 김현덕 Hyeon-deok Kim , 김규왕 Kyu-wang Kim

DOI: JANT Vol.28(No.4) 507-517, 2024

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Analysis of air accident investigation data led experts from ICAO and IATA member countries to agree on the need for further improvements in flight safety and led to a comprehensive review of pilot training. As a result of this review, emphasis was placed on developing pilots' technical as well as non-technical competencies related to CRM. In 2013, ICAO recommended that contracting countries implement EBT to develop and strengthen pilots' competencies to improve flight safety. This study intend to find out how Korean airlines utilize EBT training programs and how they manage threats and errors when encountering abnormal situations to secure and promote safety, which is the original purpose of operations. We sought to derive ways to improve and develop non-technical core competencies.

김성엽 Sung-yeob Kim , 이명식 Myeong-sik Lee , 김현덕 Hyeon-deok Kim

DOI: JANT Vol.28(No.4) 518-523, 2024

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The explosive increase in demand for drones poses a major threat to the safety of existing aircraft operations and important national facilities operating in low-altitude airspace. In order to determine the type and degree of safety threats for low-altitude airspace drones, the types and types of threats from drones are evaluated through analysis of AHP(analysis hierarchy process) for aviation workers in each field. The composition of the threat factor hierarchy from drones was designed using a specific operation risk assessment (SORA) technique previously studied by the European Aviation Safety Agency (EASA), an advanced aviation country. Based on this, it will be possible to secure the low-altitude safety operation of existing aircraft by identifying and removing prior hazards between each aircraft operation and mission performance.

이중근 Lee Joong-keun , 이정현 Lee Jung Hyun , 김현덕 Kim Hyeon-deok

DOI: JANT Vol.28(No.4) 524-531, 2024

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In a global environment, airlines are striving to secure competitiveness and generate profits through customer satisfaction. The first thing to do in order to provide services to customers is the safety of the aircraft, and the basis for realizing safety is the continuous maintenance of maintenance quality. The degree of development of aviation technology is progressing unimaginably fast, but the overall environment of aviation mechanics working at the front line to maintain maintenance quality remains largely unchanged. This study aims to identify the level of education and training provided to aircraft maintenance engineers and safety culture, and to examine the effect of self-esteem on maintenance quality. Previous studies have been conducted on maintenance engineers’ education and training, organizational performance, and job stress, but there has been a lack of studies on maintenance quality. Therefore, this study aims to identify the relationship between variables affecting maintenance quality and to suggest implications for improving maintenance quality through empirical analysis.

이동규 Dong-gyu Lee , 김경일 Kyung-il Kim , 조규섭 Gue-serb Cho , 김경택 Kyung-taek Kim

DOI: JANT Vol.28(No.4) 532-537, 2024

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In this study, wear characteristics and microstructure changes due to changes in alloy composition of Ni-Cr-Mo-V and Ni-Cr-Mo low-alloy steels used in brake discs for transportation system such as aircraft and high-speed trains. As a result of the hardness test, the hardness of C-Mo-V steel was the highest at 39.4±0.9HRc, and the hardness of Ni-Cr-Mo steel was the lowest at 32.4±0.6HRc. The friction coefficient tended to decrease as the vertical load increased. At a vertical load of 1 N, the friction coefficient of Ni-Cr-Mo steel was the highest at 0.842, and at a vertical load of 5 N, Mn-Cr-V steel was the highest at 0.696. Ni-Cr-Mo showed the largest wear scar width, depth, and wear amount, with a width of 711 μm, a depth of 8.24 μm, and a wear amount of 11 mg under a vertical load of 1 N, and a width of 1,017 μm, a depth of 19.17 μm, and a wear amount of 17 mg under a vertical load of 5 N. As a result of wear mechanism analysis, ploughing, delamination, and adhesion in all specimens, with plastic deformation being more prominently observed in Ni-Cr-Mo.

여준호 Junho Yeo , 이종익 Jong-ig Lee

DOI: JANT Vol.28(No.4) 538-543, 2024

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In this paper, the miniaturization of a chipless RFID tag using an interdigital-capacitor-shaped slot was studied. The proposed interdigital-capacitor-shaped slot was appended on the rectangular conductor plate printed on one side of a 20 mm × 50 mm FR4 substrate with a thickness of 0.8 mm. The resonant dip frequency of the bistatic RCS for the proposed interdigital-capacitor-shaped slot was compared with the cases when the H-shaped and modified bent H-shaped slots were added, respectively, on the conductor plate. The simulated resonant dip frequencies for H-shaped and modified bent H-shaped slots were 5.907 GHz and 3.741 GHz, respectively. When the proposed interdigital-capacitor-shaped slot was added, the resonant dip frequency was decreased to 2.889 GHz, and, therefore, the slot length was reduced by 51.1% compared to the H-shaped slot case. Experiment results show that the resonant dip frequency of the fabricated nterdigital-capacitor-shaped slot was 3.07 GHz.

김호형 Hohyeong Kim , 김민지 Min-ji Kim , 김경택 Kyung-taek Kim

DOI: JANT Vol.28(No.4) 544-551, 2024

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[Abstract] In this study, the electrochemical polarization data required for the simulation of the plating process, simulation of plating conditions, and characterization of the plating layer were discussed. The electrochemical polarization data obtained by potentiodynamic polarization tests and potentiostat analysis of Ni and Cu were used to observe changes in the overvoltage distribution with the flow conditions of the plating solution. In the simulation of plating conditions, the current density distribution and plating thickness distribution were evaluated under different variables to analyze the influence of the location and number of contacts on the rack pins on the plating quality. Simulation results under variables such as anode geometry, interpole distance, auxiliary anode placement, and variation of substrate spacing were used to explore ways to improve plating thickness deviation. Additionally, plating layer characterization analyzed the thickness, adhesion, and delamination of the plating layer with and without buffer layer formation. The simulation results can be utilized as important basic data for improving the efficiency and quality of the plating process.

이성렬 Seong-real Lee

DOI: JANT Vol.28(No.4) 552-558, 2024

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In dispersion management, which involves additionally inserting a dispersion compensation fiber of an appropriate length to eliminate or reduce the chromatic dispersion of a single-mode fiber, determining the form of the dispersion map, which is the cumulative dispersion profile according to the transmission distance, is the most basic and important. In this paper, the various symmetric dispersion map based on trapezoids applied to dispersion-managed links combined with mid-span spectral inversion (MSSI), which compensates for the distortion caused by Kerr nonlinear effects through optical phase conjugation in the middle of the entire transmission link are proposed, and the effect of each dispersion map on distortion compensation of wavelength division multiplexed (WDM) signals is analyzed. Although the degree of compensation varies depending on the factors that determine the detailed shape of the proposed trapezoid-shaped dispersion map and RDPS (residual dispersion per span), overall, it was confirmed that distortion compensation for signals with a small extinction ratio was more effective than distortion compensation for WDM channel signals with a large extinction ratio.

이서영 Seo-young Lee , 유연휘 Yeon-hwi You , 박효경 Hyo-gyeong Park , 박병주 Byeong-ju Park , 문일영 Il-young Moon

DOI: JANT Vol.28(No.4) 559-565, 2024

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Research on autonomous vehicles is being actively conducted. As autonomous vehicles emerge, there will be a transitional period in which traditional and autonomous vehicles coexist, potentially leading to a higher accident rate. Currently, when a traffic accident occurs, the fault ratio is determined according to the criteria set by the General Insurance Association of Korea. However, the time required to investigate the type of accident is substantial. Additionally, there is an increasing trend in fault ratio disputes, with requests for reconsideration even after the fault ratio has been determined. To reduce these temporal and material costs, we propose a deep learning model that automatically determines fault ratios. In this study, we aimed to determine fault ratios based on accident video through a image classification model based on ResNet-18 and video action recognition using TSN. If this model commercialized, could significantly reduce the time required to measure fault ratios. Moreover, it provides an objective metric for fault ratios that can be offered to the parties involved, potentially alleviating fault ratio disputes.

이영교 Young-kyo Lee

DOI: JANT Vol.28(No.4) 566-573, 2024

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Applying autonomous driving technology to construction sites is very difficult due to safety issues. However, the application of various positioning and sensing devices, such as cameras and radars, to construction equipment is very active. Based on these technological trends, the government is making various efforts, including the Serious Accident Punishment Act and support for industrial safety management expenses, to reduce the incidence of accidents caused by construction equipment and industrial vehicles. And, related industries have been developing various safety equipment over the past few years and applying them to the field. In this paper, we investigate the current status of safety equipment-related technologies currently applied to construction equipment and industrial vehicles, and propose a direction for the development of safety technology in construction equipment based on artificial intelligence. Improving the safety and work efficiency of construction equipment based on the technology proposed in this paper should be reviewed through simulation in the future.

임익수 Eeksu Leem

DOI: JANT Vol.28(No.4) 574-581, 2024

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This study explores the usability of extended reality (XR) content tailored for production process training, with a focus on user experience. Participants engaged with extended reality training modules, and qualitative data was subsequently collected through interviews. These interviews evaluated the hardware, user interface, and overall user satisfaction. The analysis utilized python packages for keyword extraction and word cloud visualization, offering insights into user perceptions. The findings revealed that although the hardware was deemed comfortable, concerns were raised regarding its weight and heat emission. The interactive interface, which relies on hand tracking, encountered issues with recognition rates, leading to suggestions for alternative input methods. Users acknowledged extended reality’s potential impact on industries like healthcare and education, sharing both positive and negative views on the technology. This research enhances our understanding of user responses and guides the future enhancement of extended reality content for industrial applications, aiming to improve its quality and practical usability