Search Results (3,855)

Unmanned aerial vehicles (UAVs) are a new, adaptable technology that has found its way into both military and civilian applications. Preserving the integrity of the UAV and its security during flight and, in particular, during the landing stage is essential for the performance of the assigned mission of the aircraft. This research examines a developed aircraft scheme. It was tested for static and dynamic stability in an XFLR5 virtual aerodynamic environment. The obtained results were transferred to MATLAB-Simulink, where the flight control algorithm was synthesized, the landing mode was set using an engineering flight plan, and an autonomous landing was simulated in the presence of wind disturbances with turbulence and noisy operation of the information measurement complex of the UAV. The algorithm for controlling the landing during the execution of the set flight trajectory, which contains a Kalman estimator and an optimal LQR controller combined in a general LQG control algorithm, is studied. Full article

The current building industry is facing challenges of labor shortages and labor-intensive practices. Effectively collaborating with robots will be crucial for industry upgrading. This research introduces a MR iterative design and robot-assisted construction mode based on human–robot collaboration, facilitating an integrated process innovation from design to construction. The development of the ROCOS (Robot Collaboration System) comprises three key aspects: (1) Layout Stage: using MR technology to layout the site, forming a full-scale integrated virtual and physical digital twin design environment. (2) Design Stage: conducting virtual iterative design in the digital twin environment and automatically simulating assembly processes. (3) Assembly Stage: translating simulated results into assembly path commands and driving a robotic arm to perform actual assembly. In the end, this research setup two experiments to examine the feasibility of this iterative design–construction loop script. The results showed that although the presence of obstacles reduced the designer’s freedom and increased the number of steps, the designer could still finish both tasks. This means that the ROCOS has value in the prototype of human–robot collaboration. In addition, some valuable findings from users’ feedback showed that potential improvements can be addressed in operability, customization, and real construction scenarios. Full article

Background: In recent years, there has been a growing use of technological advancements to enhance the rehabilitation of individuals who have suffered from cerebrovascular accidents. Virtual reality rehabilitation programs enable patients to engage in a customized therapy program while interacting with a computer-generated environment. Therefore, our goal was to investigate the effectiveness of virtual reality in occupational therapy for people’s rehabilitation after a cerebrovascular accident. Methods: We systematically searched databases (Pubmed/Medline, Scopus, Web of Science, and Science Direct) for randomized controlled trials published within the last 10 years. Studies involving adult stroke survivors undergoing virtual reality-based interventions aimed at improving upper-extremity motor function were included. The quality assessment followed PRISMA guidelines, with the risk of bias assessed using the Cochrane tool (version 6.4) and methodological quality evaluated using GRADEpro. Results: We selected sixteen studies that met the main criteria for the implementation of virtual reality technology. The interventions described in the articles focused mainly on the upper extremities and their fine motor skills. Conclusions: When used in conventional treatments to improve people’s motor and cognitive functions after a cerebrovascular accident, virtual reality emerges as a beneficial tool. Additionally, virtual reality encourages adherence to the interventional process of rehabilitation through occupational therapy. Full article

Cloud computing, as the most widely applied and prominent domain of distributed systems, has brought numerous advantages to users, including high resource sharing efficiency, strong availability, and excellent scalability. However, the complexity of cloud computing environments also introduces various risks and challenges. In the current landscape with numerous cloud service providers and diverse hardware configurations in cloud environments, addressing challenges such as establishing trust chains, achieving general-purpose virtual remote attestation, and ensuring secure virtual machine migration becomes a crucial issue that traditional remote attestation architectures cannot adequately handle. Confronted with these issues in a heterogeneous multi-cloud environment, we present a targeted solution—a secure migration-enabled generic virtual remote attestation architecture based on improved TEE. We introduce a hardware trusted module to establish and bind with a Virtual Root of Trust (VRoT), addressing the challenge of trust chain establishment. Simultaneously, our architecture utilizes the VRoT within TEE to realize a general-purpose virtual remote attestation solution across heterogeneous hardware configurations. Furthermore, we design a controller deployed in the trusted domain to verify migration conditions, facilitate key exchange, and manage the migration process, ensuring the security and integrity of virtual machine migration. Lastly, we conduct rigorous experiments to measure the overhead and performance of our proposed remote attestation scheme and virtual machine secure migration process. The results unequivocally demonstrate that our architecture provides better generality and migration security with only marginal overhead compared to other traditional remote attestation solutions. Full article

Rehabilitation involves all types of patients, including people with schizophrenia. Schizophrenia is considered a complex syndrome characterized in general by fundamental and characteristic distortions of thinking and perception. The quality of life of a person with schizophrenia can be compromised by difficulty in carrying out their daily tasks and by the social stigma of their condition. The importance of training and sensitizing students in rehabilitation areas to this type of problem to improve the rehabilitation processes in which they will participate as future professionals involves empathy and the ability to communicate with these populations. It is possible through virtual reality to create immersive environments to simulate some psychotic symptoms characteristic of people with schizophrenia, such as visual hallucinations and hearing voices. The aim of this study was to test the effect of exposure to experiences characteristic of schizophrenia through two different types of immersive environments, graphical computational virtual reality and 360° video, on students from areas of social rehabilitation regarding empathy, social distance, and attitudes towards people with schizophrenia. Although the results were positive for the three parameters under study, no significant differences were found for each of them between the environments to which the participants were exposed. This study concluded that the choice between the two types of immersive environments should be based on the project’s objectives, the target audience’s needs, and available resources, rather than the type of environment itself, as their impact was similar. Full article

Shape modeling is a dynamic area in computer graphics with significant applications in computer-aided design, animation, architecture, and entertainment. Virtual sculpting, a key paradigm in free-form modeling, has traditionally been performed on desktop computers where users manipulate meshes with controllers and view the models on two-dimensional displays. However, the advent of Extended Reality (XR) technology has ushered in immersive interactive experiences, expanding the possibilities for virtual sculpting across various environments. A real-time virtual sculpting system implemented in a Virtual Reality (VR) setting is introduced in this paper, utilizing quasi-uniform meshes as the foundational structure. In our innovative sculpting system, we design an integrated framework encompassing a surface selection algorithm, mesh optimization technique, mesh deformation strategy, and topology fusion methodology, which are all tailored to meet the needs of the sculpting process. The universal, user-friendly sculpting tools designed to support free-form topology are offered in this system, ensuring that the meshes remain watertight, manifold, and free from self-intersections throughout the sculpting process. The models produced are versatile and suitable for use in diverse fields such as gaming, art, and education. Experimental results confirm the system’s real-time performance and universality, highlighting its user-centric design. Full article

Network visualization, in mathematics often referred to as graph visualization, has evolved significantly over time, offering various methods to effectively represent complex data structures. New methods and devices advance the possibilities of visualization both from the point of view of the quality of displayed information and of the possibilities of visualizing a larger amount of data. Immersive visualization includes the user directly in presented visual representation but requires a native 3D environment for direct interaction with visualized information. This article describes an approach to creating a force-directed immersive 3D network visualization algorithm available for application in immersive environments, such as a cave automatic virtual environment or virtual reality. The algorithm aims to address the challenge of creating visually appealing and easily interpretable visualizations by utilizing 3D space and the Unity engine. The results show successfully visualized data and developed interactive visualization methods, overcoming limitations of basic force-directed implementations. The main contribution of the presented research is the force-directed algorithm with springs and controlled placement as an immersive visualization technique that combines the use of springs and attractive forces to stabilize a network in a 3D environment. Full article

In this study, a cooperative robotic system comprising two Selective Compliance Assembly Robot Arm (SCARA) robots was developed and simulated. An algorithm was proposed for the coordination of robots in cooperative tasks, along with a Rapidly exploring Random Tree (RRT) path planner for obstacle avoidance. The proposed system proved effective in transferring objects between robots and in handling various scenarios of variable complexity without collisions. The implementation of advanced trajectory planning and coordination algorithms significantly improves the adaptability and autonomy of robotic systems, allowing robots to predict and react to the movements of their counterparts and changes in the environment in real time. This capability is crucial for maintaining a safe and efficient work environment. The importance of synchronization and effective communication between robots is highlighted to avoid collisions and optimize trajectories and cycle times. All tests were conducted in virtual environments, allowing for the evaluation and refinement of the performance of the robots’ performance under controlled conditions. The positive results obtained in the simulations suggest that the system is well suited for future practical implementation in industrial and manufacturing applications, such as chemical handling, collaborative welding, quality inspection, among others. These findings underscore the potential of the cooperative SCARA system to improve the efficiency and safety in industrial applications using advanced algorithms and control techniques, establishing a solid foundation for future research and development in the field of cooperative robotics. Full article

Sensory analysis methodologies are performed in sensory booths designed to minimise external stimuli, lacking ecological validity. Immersive environments are used to introduce contextual cues, but there is a lack of studies using mixed reality systems. The main goal of this study was to evaluate an augmented virtuality (AV) system where participants are inserted into a virtual environment and evaluate a real product, being able to interact with both dimensions. A panel of 102 consumers evaluated five samples of commercial peach nectars in three sessions, each in a different environment: public food court, living room (AV environments), and laboratory (traditional sensory booth). Consumers rated overall liking, followed by open comments, and also answered an Engagement (EQ) and a Presence Questionnaire (PQ). The type of environment only affected hedonic discrimination among samples, with the laboratory setting being the only one with sample discrimination. Nonetheless, each sample was not evaluated differently across the different environments. Concerning engagement, the environment only significantly influenced the EQ’s ‘Affective Value’ factor, being higher when using an AV system. The level of presence in the virtual environment was significantly higher in the public food court, being significantly correlated with the EQ factor scores. Full article

The evolving landscape of industrial manufacturing is increasingly embracing automation within smart factories. However, the critical role of human operators, particularly in manual assembly and disassembly tasks, remains undiminished. This paper explores the complexities arising from mass customization and remanufacturing, which significantly enhance the intricacy of these manual tasks. Human involvement is essential in these tasks due to their complexity, necessitating a structured learning process to enhance efficiency and mitigate the learning–forgetting cycle. This study focuses on the utilization of virtual reality (VR) as an innovative training tool to address these challenges. By conducting a systematic literature review (SLR) on the impact of VR on training operators for assembly and disassembly tasks, this paper evaluates the current level of VR application, the used technologies, the operator performance, and the VR benefits and limitations. The analysis reveals a limited but promising application of VR in training, highlighting its potential to improve learning outcomes, productivity, and safety while reducing costs. However, the research also identifies gaps in the practical application of VR for training purposes suggesting a future research agenda to explore its full potential. Full article

As technology advances, the field of electrical and computer engineering continuously demands the introduction of innovative new tools and methodologies to facilitate the effective learning and comprehension of fundamental concepts. This research addresses an identified gap in technology-augmented education capabilities and researches the integration of virtual reality (VR) technology with real-time electronic circuit simulation to enable and enhance the visualization of non-observable concepts such as voltage distribution and current flow within these circuits. In this paper, we describe the development of our immersive educational platform, which makes understanding these abstract concepts intuitive and engaging. This research also involves the design and development of a VR-based circuit simulation environment. By leveraging VR’s immersive capabilities, our system enables users to physically interact with electronic components, observe the flow of electrical signals, and manipulate circuit parameters in real-time. Through this immersive experience, learners can gain a deeper understanding of fundamental electronic principles, transcending the limitations of traditional two-dimensional diagrams and equations. Furthermore, this research focuses on the implementation of advanced and novel visualization techniques within the VR environment for non-observable electrical and electromagnetic properties, providing users with a clearer and more intuitive understanding of electrical circuit concepts. Examples include color-coded pathways for current flow and dynamic voltage gradient visualization. Additionally, real-time data representation and graphical overlays are researched and integrated to offer users insights into the dynamic behavior of circuits, allowing for better analysis and troubleshooting. Full article

Remote operations have been greatly enhanced by advancements in technology, enabling remote control of machinery in hazardous environments. However, it is still a challenge to design remote control interfaces and provide feedback in a way that would enhance situational awareness without negatively affecting cognitive load. This study investigates how different audio feedback designs can support remote boom operation and, additionally, explores the potential impact of gamification elements on operator performance and motivation. Due to COVID-19 restrictions, this study was conducted remotely with 16 participants using a simulated environment featuring a virtual excavator. Participants performed digging tasks using two audio feedback designs: frequency-modulated beeping and realistic spatialized steam sounds. The findings indicate that both audio designs are beneficial for remote boom operations: the beeping sound was perceived as more comfortable and efficient in determining the proximity of a hidden object and helped in avoiding collisions, whereas spatial sounds enhanced the sense of presence. Therefore, we suggest combining both audio designs for optimal performance and emphasize the importance of customizable feedback in remote operations. This study also revealed that gamification elements could both positively and negatively affect performance and motivation, highlighting the need for careful design tailored to specific task requirements. Full article

Raster data represent one of the fundamental data formats utilized in GIS. As the technology used to observe the Earth continues to evolve, the spatial and temporal resolution of raster data is becoming increasingly refined, while the data scale is expanding. One of the key issues in the development of GIS technology is to determine how to make large-scale raster data better to provide computation, visualization, and analysis services in the Internet environment. This paper proposes a decentralized COG-pyramid-based map service method (DCPMS). In comparison to traditional raster data online service technology, such as GIS servers and static tiles, DCPMS employs virtual mapping to reduce data storage costs and combines tile technology with a cloud-native storage scheme to enhance the concurrency of supportable requests. Furthermore, the band calculation process is shifted to the client, thereby effectively resolving the issue of efficient customized band calculation and data rendering in the context of a large-scale raster data online service. The results indicate DCPMS delivers commendable performance. Its decentralized architecture significantly enhances performance in high concurrency scenarios. With a thousand concurrent requests, the response time of DCPMS is reduced by 74% compared to the GIS server. Moreover, this service exhibits considerable strengths in data preprocessing and storage, suggesting a novel pathway for future technical improvement of large-scale raster data map services. Full article

This paper proposes a kinetostatic approach for analyzing the joint torques of a redundant snake robot. The method is suitable for weightless space environments. With the high degree of freedom and flexible cable actuation, the redundant snake robot is well-suited for utilization in space-weightless environments. This method reduces computational cost by using the multiplication of matrices and vectors instead of inverse matrices. Taking advantage of the velocity screw (twist) and force screw (wrench), this strategy provides an idea for redundant serial robots to achieve the calculation of joint torques. This methodology is straightforward for programming and has good computational efficiency. The instantaneous work performed by the actuation is expressed with the force screw. According to the principle of virtual work, the kinetostatic equation of the robot can be obtained and the torque required for each joint can be determined. Meanwhile, to solve the inertia force generated by joint acceleration, D’Alembert’s principle is adopted to transform the dynamic problem into a static problem. Through kinetostatic analysis of a redundant snake robot, this paper shows the approach of establishing the kinetostatic model to calculate the torque in screw form. At the same time, the actuation distribution of the redundant snake robot is also cracked effectively for practical purposes. Due to the difficulty of achieving weightless space environments, this paper validates the method by using ADAMS simulation without gravity in the simulation. Full article

Virtual commissioning (VC), defined as the simulation and testing of systems in a virtual environment before physical implementation, plays a key role in addressing the challenges of integrating and validating complex systems efficiently and effectively. This paper focuses on the topic of virtual commissioning, summarizing and organizing existing research in the field. The paper provides a comprehensive overview of various design methods and technologies currently in use. A case study of virtual commissioning is also presented within the area of the Cyber-Physical Manufacturing Systems Laboratory of the Széchenyi István University, detailing the solution steps taken. Drawing on both research and practical experience, the paper proposes a novel framework to support virtual commissioning design, referred to as the “Virtual Commissioning House” (VCH). The methodology is evaluated through comparisons with existing virtual commissioning solutions, demonstrating its effectiveness. Full article