• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.5
• /
• pp.698-704
• /
• 2010

The machine vision system has been widely applied at automatic inspection field of the industries. Especially, the machine vision system shows good performance at difficult inspection field by contact method. In this paper, the automatic system of a slant method to inspect screw/bolt shape using machine vision is developed. The inspection system uses pattern matching method that search similar degree of the lucidity, the average lucidity, length and angle of inspection set up area using a circular scan and a line scan method. Also the feeding method for inspection product is the slant method, and feed rate is controlled by the ramp angle adjustment. This inspection system is composed of a feeding device, a transfer device, vision systems, a lighting device and computer, and is composed the sorting discharge system of the inferior product. The performance test carried out the feeding speed, the shape correct degree and the sorting discharge speed according to the type of screw/bolt. This sorting inspection system showed a satisfied test results in whole inspection items. Presently, this sorting inspection system is being used in the manufacturing process of screw/bolt usefully.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.146-148
• /
• 2002

An automatic inspection vision systems whose development was the industry applications motor rear side member. This system are connected to the 9 ea camera fur the process inspection the bolt, nuts, units in the rear side member product. This automatic inspection vision systems can perform inspection of not attached the bolt, nuts, units, etc fast and accuracy in react time fashion. And then perform very sophisticated inspection which human workers can not perform.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.173-176
• /
• 2005

The present work has been studied the reliability improvement of inspection method for explosive bolt body. The standard value of impact test is made from impact test of explosive bolt body and a useful data is established to the correlation between the hardness and impact data of bolt body. The method is overcome an error obtained from conventional inspection by analysing the mechanical data from each inspection and can be improved to the reliability when mechanical property of explosive bolt body is inspected.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1331-1332
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.259-260
• /
• 2010

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.10
• /
• pp.3608-3626
• /
• 2021

The detection of bolts is an important task in high-speed train inspection systems, and it is frequently performed to ensure the safety of trains. The difficulty of the vision-based bolt inspection system lies in small sample defect detection, which makes the end-to-end network ineffective. In this paper, the problem is resolved in two stages, which includes the detection network and cascaded classification networks. For small bolt detection, all bolts including defective bolts and normal bolts are put together for conducting annotation training, a new loss function and a new boundingbox selection based on the smallest axis-aligned convex set are proposed. These allow YOLOv3 network to obtain the accurate position and bounding box of the various bolts. The average precision has been greatly improved on PASCAL VOC, MS COCO and actual data set. After that, the Siamese network is employed for estimating the status of the bolts. Using the convolutional Siamese network, we are able to get strong results on few-shot classification. Extensive experiments and comparisons on actual data set show that the system outperforms state-of-the-art algorithms in bolt inspection.

• Journal of the Korean Society of Safety
• /
• v.35 no.5
• /
• pp.1-8
• /
• 2020

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, microstructural characterization, fractography analysis by Optical Microscope(OM) and Scanning Electron Microscopy(SEM), and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.

• Journal of Digital Convergence
• /
• v.16 no.3
• /
• pp.303-309
• /
• 2018

Computer vision technology is a component inspection to obtain a video image from the camera to the machine to perform the capabilities of the human eye with a field of artificial intelligence, and then analyzed by the algorithm to determine to determine the good and bad of production parts It is widely applied. Shape inspection method was used as how to identify the location of the start point and the end point of the search range, measure the height to the line scan method, in such a manner as to determine the presence or absence of the bolt tabs average brightness of the inspection area in a circular scan type value And the degree of similarity was calculated. The total time it takes to test in the test performance tests of two types of bolts tab enables test 300 min, and demonstrated the accuracy and efficiency of the inspection on the production line represented a complete inspection accuracy.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.4
• /
• pp.135-140
• /
• 2005

In case of rock bolt useable by tunnel reinforcement methods at field is applied problem of typical rock bolt pull test diagram method propositional in documents and is not thesis of clearness analysis basis about result of rock bolt pull test. So this paper suggested in consideration of foreign basis and field condition that the first, "suggestion of apposite diagram method at tight ground and difference application of rock bolt pull test method at loose and tight ground" and the second, "thesis of estimation basis non-thesis of design and specification, test etc".

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.6
• /
• pp.124-131
• /
• 2010

Rock Bolt generally utilizes deformed reinforcing bar welded from structural steel of which strength is higher than required for making advantageous use of the support function of ground. In the condition with highly corrosive underground water, however, problem frequently occurs on tunnel and slope stabilization in terms of repair, rehabilitation and maintenance issues due to the destruction of Rock Bolt by corrosion of steel. A structural performance evaluation for GFRP Rock Bolt was conducted for the purpose of resolving the foregoing problem and at the same time developing a permanently-usable support material. This study intended to evaluate the safety factor of GFRP Rock Bolt by implementing the slope stability interpretation via structural analysis on the basis of its structural characteristics derived from both tensile force function test and shear force function test. It is judged based on the results that GFRP Rock Bolt would secure sufficient ground stability as an alternative material for existing Steel Rock Bolt.