A COMPARISON OF LASER AND STRUCTURED LIGHT SCANNING TECHNOLOGIES FOR ARCHAEOLOGICAL APPLICATIONS

Reverse engineering and in particular three-dimensional digitization have become an essential part of the documentation of archaeological findings. 3D scanning produces a high-precision digital reference document. The factors that influence the quality of the 3D scanned data are the scanned object’s surface colour, its glossiness and geometry, and the ambient light during the scanning process. However, the actual equipment and scanning technologies are of primary importance. The current paper presents a qualitative and quantitative comparison between two 3D scanning devices of different technologies; structured light 3D scanning and laser 3D scanning. The benchmark for this comparison is an ancient Roman vase from the city of Thessaloniki, Greece. The object was scanned with every possible setting on each scanner, but only one configuration of settings on each device was selected for the final comparison. The main criterion for the final selection of the two 3D models acquired with the use of the two technologies was the proximity in the number of points and polygons produced for digitally restoring the ancient vase in the best possible way. The results indicate important differences regarding the accuracy of the final digital model. The laser technology produced better accuracy but with a significant cost in scanning time and model data size. On the other hand, the structured light technology achieved the optimal combination of scanning quality and accuracy, along with reduced acquisition time of scan data.

Simulation study on power system short circuit fault based on EMTP

Electromagnetic transient simulation program EMTP is a common simulation commercial software in power system. It can effectively analyze and study power system. In this paper, EMTP is used to build the power system simulation model, and a variety of short-circuit faults in the power system are simulated and analyzed. The results show that the results accord with the actual theory, and the waveform can accurately and intuitively investigate the dynamic characteristics of power system faults. In addition, through the simulation comparison and analysis between different faults, it can be seen that the three-phase short-circuit fault is the most serious fault in the power system, which should be avoided in the actual production and life. This shows that EMTP is a powerful tool for power system simulation research, and provides a reference for the actual equipment selection requirements of the project.

Collaborative Augmented Digital Twin: A Novel Open-Source Augmented Reality Solution for Training and Maintenance Processes in the Shipyard of the Future

Large companies use a lot of resources on workshop operator training and industrial machinery maintenance since the lack of this practice or its poor implementation increases the cost and risks of operating and handling sensitive and/or hazardous machinery. Industrial Augmented Reality (IAR), a major technology in the Industry 4.0 paradigm that may enhance worker performance, minimize hazards and improve manufacturing processes, could be beneficial in this situation. This paper presents an IAR solution that allows for visualizing and interacting with the digital twin of a critical system. Specifically, the augmented digital twin of an industrial cooler was developed. The proposed IAR system provides a dynamic way to perform operator training with a full-size model of the actual equipment and to provide step-by-step guidance so that maintenance processes can be performed more safely and efficiently. The proposed system also allows several users to use devices at the same time, creating a new type of collaborative interaction by viewing the model in the same place and state. Performance tests with many simultaneous users have been conducted, with response latency being measured as the number of connected users grows. Furthermore, the suggested IAR system has been thoroughly tested in a real-world industrial environment.

A Study on the Response of the Rehabilitation Lower Device using Sliding Mode Controller

This paper presents the application of the sliding mode controller to simulate the control of a 3 Degree of Freedom (DoF) robot model that supports lower extremity rehabilitation exercises for stroke patients. The 3 DoF robot model has an established dynamic differential equation for each joint. This paper studied the response of links of the research model with a sliding mode controller proposed as the control solution. Matlab software was used in simulations of ankle, knee, and hip joints' drive for 2 cases, without and with load. Compared with other studies, the research results show that the sliding controller results in slight angular errors when applied to the research model, while the torque of the joints remains low. This result is the basis for calculating and selecting parameters for the actuator when manufacturing the actual equipment.

Ergonomic Hazards in the Workplace: Assessment, Evaluation and Prevention in the Educational Environment of Holy Cross College

This research was conducted to assess, evaluate and prevent the ergonomics hazards in the educational environment of Holy Cross College. College instructors at various workstations across the college facilities are among those that participate. The data was gathered through the use of an online survey form. It consists of 45 questions designed to have insight on the actual equipment setup, work posture, and work design, and environment utilized by the college faculty. The majority of the detected risks are at a critical level and may cause severe loss to the organization's scope, quality, schedule, and cost. The findings provided the necessary safety norms and resources to prevent ergonomic hazards that result in ergonomic health problems. All hazards designated as critical can be kept to minimum if actions and reactions are appropriately implemented by the relevant parties. As a result, the likelihood and magnitude of its occurrence and effects are reduced.

The analysis of aircraft equipment essential for the use of ADS-B, implementation in 2021

The fluidity of air traffic depends mainly on the coherence of the minimum separation requirements between aircraft in the airspace and the advanced exchange of air traffic information obtained through the interoperability of ATM systems and surveillance data exchange systems between aircraft and ATM system. In the paper on the implementation of unified global solutions, ICAO indicated that the key requirement is that the functions of on-ground ATM systems concerning the source of information surveillance (aircraft position). ICAO encourages the widespread use of ADS-B technology (Automatic Dependent Surveillance – Broadcast). The paper presents the concept of using ADS-B, analyzes the problems resulting from the need to ensure interoperability, and shows the results of measurements and analyzes of the actual equipment level of aircraft operating from two airports in TMA Warsaw: Warsaw Chopin Airport (EPWA) and Warsaw Modlin (EPMO). In summary, the authors refer to the level of meeting the requirements of the ADS-B equipment in the context of formal and legal requirements and the time remaining until the published requirements are fully applicable.

Microwave Imaging for Breast Cancer Detection

Microwave imaging (MI) is characterized by no exposure, stronger contrast between soft tissues than X-rays and ultrasound, and a smaller device scale. This chapter describes the electrical properties of the breast tissue that underlie MI, and then outlines the MI hardware configuration and three imaging algorithms: confocal imaging, scattering tomography, and near-field holography. After that, we will introduce the actual equipment and experimental results using the three imaging algorithms. Finally, we will summarize the challenges of realizing a medical imaging device using MI.

Vibration-Based Detection of Loosened Bolts on Pipes Attached to Bridges

U-bolts are critical points of maintenance in pipeline facilities supported by girders of bridges. However, it is difficult to detect loosened U-bolts by visual inspection. To avoid this problem, we have developed a vibration-based method to detect loosening of bolts based on measurements of actual equipment. First, the vibration of a communication pipeline attached to a road bridge was measured when vehicles passed over it. During the measurements, the U-bolts were set in tightened and loosened states. We found that the frequency changes between the tightened and loosened states was too small for practical use. On the other hand, a strong spectrum in the high frequency region (above 80 Hz) appeared only in the tightened state. Next, a model facility was built to simulate a communication pipeline attached to bridge. A hammering test and modal and frequency response analyses were performed by using the finite element method (FEM). The results suggested that high frequency peaks appearing only in the tightened U-bolt are due to the higher rate of force transfer of the natural frequency from the platform. In addition, the pipe is strongly fixed when the U-bolt is tightened, which may lead to stronger high order modes that cause complex deformation of the pipe. The conventional method is to detect loosening of bolts from changes in the natural frequency. However, in actual equipment, confirming the absence of a high-frequency spectrum is more suitable for detecting loosened bolts.

Position and speed optimization of servo motor control through FPGA

We have put our model in this paper in which we will be controlling the speed and direction of the servomotor through FPGA. So, as to guarantee the precision from the check control procedure, we have made a project in which the document provides the control plane associated with servo motor depending on Altera DE1 board gentle primary processor as program controller. The system utilizes FPGA since the primary gadget, as well as within Quartus II 10.0 program atmosphere. The associated control components aremade to type a good executable control program in which speed and direction will be controlled the servo motor performance. The particular handle signs from your handle method are usually separated and amplified which results in the push to appreciate the particular handle with the servo motor. Based on the features associated with Altera, it is expounded through 2 facets of equipment’s hardware as well as a software program that supplies an answer for that style associated with the servo control system. This particular document utilizes the actual PID control formula to manage the actual common screening device to attain versatile as well as precise control reasons. The actual equipment execution from the PID control formula is put in place through FPGA; precise as well as effective control program is built to enhance the speed and performance of the servomotor through FPGA.

Research on Roller Status Diagnosis of CRDM Based on SWT and HHT

For the control rod drive mechanism roller vibration signal’s characteristics of nonlinear and nonstationary. Based on actual equipment life experiment and roller fault experiment, a status diagnosis method of roller of control rod drive mechanism based on Semi-soft wavelet threshold and Hilbert-Huang transform is proposed. Firstly, semi-soft wavelet threshold method is used to reduce noise interference and the influence of end-point effect on empirical mode decomposition, and the improved Hilbert transform method is used to extract the fault characteristics of roller vibration signal. The experimental results show that the method can effectively eliminate the interference of noises and realize the status diagnosis of the roller.