• Journal of Information Processing Systems
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• v.19 no.6
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• pp.745-755
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• 2023

The wire rope is an indispensable production machinery in coal mines. It is the main force-bearing equipment of the underground traction system. Accurate detection of wire rope defects and positions exerts an exceedingly crucial role in safe production. The existing defect detection solutions exhibit some deficiencies pertaining to the flexibility, accuracy and real-time performance of wire rope defect detection. To solve the aforementioned problems, this study utilizes the camera to sample the wire rope before the well entry, and proposes an object based on YOLOv5. The surface small-defect detection model realizes the accurate detection of small defects outside the wire rope. The transfer learning method is also introduced to enhance the model accuracy of small sample training. Herein, the enhanced YOLOv5 algorithm effectively enhances the accuracy of target detection and solves the defect detection problem of wire rope utilized in mine, and somewhat avoids accidents occasioned by wire rope damage. After a large number of experiments, it is revealed that in the task of wire rope defect detection, the average correctness rate and the average accuracy rate of the model are significantly enhanced with those before the modification, and that the detection speed can be maintained at a real-time level.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.35-38
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• 2003

The wire rope, one of the component of the elevator, is extremely important for the sage operation of the elevator. That is why the wire rope is replaced at a specific interval regradless of the operating conditions or the degree of damage to prevent the breakage of the wire rope. This is the waste of resources, causing economic and environmental loss. This paper has surveyed and analyzed and analyzed the status of replacing wire-rope by buildings that use elevators, in order to compare the replacement cycles of the wire rope under each operating conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.3
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• pp.418-424
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• 2014

A large number of wire rope has been used in various industries such as cranes and elevators. When wire used for a long time, wire defects occur such as disconnection and wear. It leads to an accident and damage to life and property. To prevent this accident, we proposed a wire rope fault detection system in this paper. We constructed the whole system choosing the leakage fault detection method using hall sensors and the method is simple and easy maintenance characteristics. Fault diagnosis and analysis were available through analog filter and amplification process. The amplified signal is transmitted to the computer through the data acquisition system. This signal could be obtained improved results through the digital filter process.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.4
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• pp.417-423
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• 2015

In this study, Magnetic Flux Leakage(MFL)-based inspection system was applied to detect the local fault of wire rope. To verify the feasibility of the proposed damage detection technique, an 4-channel MFL sensor head prototype was designed and fabricated. A wire rope with several types of cross-sectional damages were fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the wire rope specimen. To interpret the condition of the wire rope, magnetic flux signals were used to determine the locations of the flaws. To improve the resolution of signal, the instantaneous variation value of magnetic flux was utilized. Measured signals from the damaged specimen were compared with thresholds set for objective decision making. Finally, the results were compared with information on actual inflicted damages to confirm the accuracy and effectiveness of the proposed cable monitoring method.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.33-41
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• 2001

Wire ropes have been widely used in industrial applications, wherever heavy weight should be carried safely or mechanical energy should be transmitted fast. Especially, wire rope failures in operating elevator may lead to extensive property damage and serious injury to nearby personnel. Hence, it is very important to inspect wire rope periodically. Failure defection of wire rope requires fundamental knowledge of wire rope construction, rope behavior, properties of fault, sensing and signal processing method. In this research, the development of a new fault detecting system incorporating Hall-effect sensors to detect flaws such as abrasion, broken wire, corrosion and deformation for aged wire ropes in elevator, is described. For using a detector as a portable instrument, several performances for implementing sensing part with Hall-effect sensor, analog signal processing unit and programs are described. Experiments and field testing results for the implemented detecting system are also given. As a result, it is verified that the detecting system has good efficiency for inspecting faults of aged wire ropes in service.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.315-323
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• 2009

Pressure oscillations triggered by the unstable interaction of dynamic flow features of the hydraulic turbine with the hydraulic plant system - including the electrical design - can at times reach significant levels and could lead to damage of plant components or could reduce component lifetime significantly. Such a problem can arise for overload as well as for part load operation of the turbine. This paper discusses an approach to analyze the overload high pressure oscillation problem using computational fluid dynamic (CFD) modeling of the hydraulic machine combined with a network modeling technique of the hydraulic system. The key factor in this analysis is the determination of the overload vortex rope volume occurring within the turbine under the runner which is acting as an active element in the system. Two different modeling techniques to compute the flow field downstream of the runner will be presented in this paper. As a first approach, single phase flow simulations are used to evaluate the vortex rope volume before moving to more sophisticated modeling which incorporates two phase flow calculations employing cavitation modeling. The influence of these different modeling strategies on the simulated plant behavior will be discussed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.306-320
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• 2021

To ensure safe port operations around the world, it is important to solve mooring problems. In particular, the many ports that face open seas have difficulties with long-period waves. As a countermeasure, the installation of a breakwater is proposed for mooring safety. However, this often cannot be put into practice because of financial issues. Instead, port terminals control berthing schedules with weather forecasting. However, mooring problems remain unsolved, because of inaccurate wave forecasting. To quantify the current situation, numerical simulations are presented with ship motions, fender deflections, and rope tensions. In addition, novel simulations for mooring ropes are proposed considering tension, friction, bending fatigue, and temperature. With this novel simulation, the optimal mooring method in terms of safety and economic efficiency was confirmed. In terms of safety, the optimal mooring method is verified to minimize dangerous mooring situations. Moreover, the optimal mooring method shows economic benefits and efficiency. It can help to reinforce the safety of port terminals and improve the efficiency of port operations.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.89-95
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• 2009

The purpose of the present study was to evaluate the safety under extreme environmental conditions and the dynamic safety under service environment conditions, of oceanographic buoy mooring systems consisting of a variety of materials, including chain, wire rope, nylon rope, and polypropylene rope. For the static safety assessment of a mooring system, after the calculation of external forces and the division of a mooring system into finite elements, the numerical integral was conducted to yield the elemental static tension until satisfying the geometrical convergence condition. To evaluate the dynamic safety, various processes were considered, including data collection about the anticipated areas for mooring, a determination of the parameters for the interpretation, the interpretation of the dynamic characteristics based on an analytic equation that takes into account the heave motion effect of a buoy hull and a mooring system, and a fatigue analysis of the linear cumulative damage. Based on the analysis results, a supplementary proposal for a wire rope that has a fracture in an actual mooring area was established.

• Journal of Korean Society of Steel Construction
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• v.22 no.2
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• pp.151-160
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• 2010

The number of cases of collapsed plastic greenhouses in farmlands has increased due to the heavy local snowfall caused by extraordinary atmospheric phenomena. Consequently, the economic losses of farmers have also increased. However the government policy in relation to damage pretension is insufficient and collapse case is repeated every year. The main reason for frame collapse is that the moment capacity of a steel pipe is not sufficient to resist a heavy snowload. In this study, experiments were conducted on the current frame system of a greenhouse with a tension tie. The frame consisted of two sections(${\phi}25.4{\times}1.5$, ${\phi}31.8{\times}1.5$), and its span length was 6.5 m. A temporary tension tie using a steel wire and a fabric rope was connected to the two joints, to which a curved beam and a straight column were connected. The pretension force was applied at the tension tie, and a vertical force simulating snowfall was applied until failure. The fabric rope frame increased the load-carrying capacity by 10-45% compared to the normal frame without a tension tie, and the steel wire frame increased the load-carrying capacity by 58-73% compared to the normal frame without a tension tie. Steel wire was found to be more effective as far as strength is concerned, but its connection details and pretension application are more difficult and complicated than those of the fabric rope. The test results thus show that the fabric rope is more preferable.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.679-681
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• 2005

The materials for transmission line construction were transported by road which opened in mountainous areas until the mid 1990s, However, from the mid 1990s, as social interest in the environment standard increases, a cable way and helicopter transport methods of construction have been applied to minimize damage to the environment and to build an environmental friendly system. The current cable way method is a single cable way system which has a lower section base to load materials into a carriage and carry them to the tower construction site by use of an engine and a main rope. Then the carriage lowers itself via a slope between the tower construction site and the lower section base. The single cable way system has the demerits of site acquisition for the lower section base, forest felling when installing the wire rope, and it is not applicable to a even topology Also it has to be installed separately at each tower site. Accordingly, to carry materials without forest felling and regardless of slope, the chain cable way system was developed to provide materials for more than two towers consecutively by use of an engine carriage and winch.