• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.1
• /
• pp.74-79
• /
• 2020

Safety inspection of cable-supported bridge has increasingly attention as many cable-supported bridges are currently constructed/operated. Whilst cables as a main component in cable-supported bridge should be inspected regularly, traditional method (visual inspection) has limitation to check the condition of cables properly due to restricted factors. It is evidently necessary to develop cable-inspection robot to overcome this concern. In this respect, the main aim in this study is to manufacture the improved robot compared with the existing robot. The improved functions of the robot in this study were that the robot can be operated in large cable diameter (greater than 200 mm) and climbing ability of the robot increases. In addition, electro-magnetic sensor as a non-destructive method in the robot was added to detect damaged cables and performance of the sensor was evaluated in indoor and field experiments. Consequently, the robot was able to move on the cable with ~0.2m/s and to detect damaged cables using the sensor. It was also confirmed that performance of the robot in field test is similar to that in indoor test.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2585-2587
• /
• 2005

본 논문은 전차선 급전 케이블 자동가설 로봇의 이동제어를 나타내었다. 작업로봇의 차륜 구동부를 모델링하여 이동제어 시스템이 작업로봇의 이동에 유용한 것을 구명하였다 실험을 하여 실용성을 검토하였다.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.1
• /
• pp.60-67
• /
• 2014

In this study, an automated cable non-destructive testing(NDT) system was developed to monitor the steel cables that are a core component of cable-stayed bridges. The magnetic flux leakage(MFL) method, which is suitable for ferromagnetic continuum structures and has been verified in previous studies, was applied to the cable inspection. A multi-channel MFL sensor head was fabricated using hall sensors and permanent magnets. A wheel-based cable climbing robot was fabricated to improve the accessibility to the cables, and operating software was developed to monitor the MFL-based NDT research and control the climbing robot. Remote data transmission and robot control were realized by applying wireless LAN communication. Finally, the developed element techniques were integrated into an MFL-based cable NDT system, and the field applicability of this system was verified through a field test at Seohae Bridge, which is a typical cable-stayed bridge currently in operation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.3
• /
• pp.246-252
• /
• 2020

Safety accidents have been reported due to falling accumulated snow from cables of cable-supported bridges. In addition to the direct damage caused by falling snow, secondary damage, such as traffic accidents, can occur. Various methods have been proposed to prevent these accidents, but there are still problems in safety and practicality. In this study, a cable robot type was selected as one of the active methods for removing accumulated snow on cables. An attempt was made to increase the climbing ability of the robot to improve the efficiency of snow removal. In addition, the available range of cable diameter for the robot can be adjusted flexibly to be applied to cables used in the field. A high-resolution camera was also installed to check the surface condition of the cable in real time to increase the utility, and be used as a cable inspection robot. A three-axis accelerometer and a tension conversion algorithm were added to measure the tension force of cables. To verify the performance, indoor and field experiments were conducted, and future improvements for the inspection robot were proposed.

• Proceedings of the KIPE Conference
• /
• 2011.11a
• /
• pp.36-37
• /
• 2011

본 논문에서는 한정된 공간에서 배터리 용량에 제약 없이 이동형 로봇이 동작할 수 있도록, 연속적으로 로봇에 전력을 공급할 수 있는 무선전력전달용 파워매트를 제안하였다. 파워매트는 단선의 급전케이블을 사용하여 케이블끼리 겹치지 않고 넓은 면적에 자기장을 발생시킬 수 있도록 구성하였고, 집전코일은 이동로봇의 바닥에 부착하여 파워매트의 모든 위치에서 연속적으로 전력을 공급 받을 수 있도록 구성하였다. 제안된 무선전력전달용 파워매트와 집전장치를 제작하였고, 시뮬레이션과 실험을 통해 우수성을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.1
• /
• pp.118-125
• /
• 2012

In this paper, an approach to designing controllers for the tension/movement control of working robot to install a stringing wire cable is presented. To design a controller, when the robot moves a certain distance maintaining constant tension, the dynamic model of a stringing wire cable which considers effects of weights according to changing lengths is presented. Also the tension at startup of the working robot is studied by numerical analysis which is based on the equation of the dynamic wire model. From the dynamic model for a stringing wire cable, working robot for tension/movement control is suggested and designed a feedforward controller with a accelerator gain to suppress a mutual interference of the both tasks of tension/movement control. Depending on the operating conditions of the working robot, the effectiveness of the suggested system has been verified by the simulation and experimental results.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.5
• /
• pp.7-13
• /
• 2009

• Journal of Ocean Engineering and Technology
• /
• v.33 no.2
• /
• pp.178-188
• /
• 2019

When burying underwater cables using robots, heading control is one of the key functions for the robots to improve task efficiency. This paper addresses the heading control issue for URI-T, an ROV for underwater construction tasks, including the burial and maintenance of cables or small diameter pipelines. Through modeling and identifying the heading motion of URI-T, the dynamic characteristics and input limitation are analyzed. Based on the identification results, a PD type controller with appropriate input treatment is designed for the heading control of URI-T. The performance of the heading controller was verified in water tank experiments. The field applicability of the proposed controller was also evaluated through the sea trial of URI-T at the East Sea, with a water depth of 500 m.

• 전기산업
• /
• v.3 no.4
• /
• pp.77-91
• /
• 1992

• Journal of Ocean Engineering and Technology
• /
• v.33 no.3
• /
• pp.300-311
• /
• 2019

An ROV trencher is a type of heavy-duty work class ROV equipped with high-pressure water jet tools for cutting into the sea floor and burying cables. This kind of trencher is mostly used for PLIB operations. This paper introduces the development of this kind of ROV trencher, which has a 698 kW power system, with a 250 kW hydraulic system and two 224 kW water jet systems. The project was launched in January 2014. After four years of design, manufacturing, and system integration, we carried out two sea trials near the Yeongilman port (about 20-30 m in depth) in Pohang to evaluate the system performance in November 2017 and August 2018. Through tests, we found that most of specifications were satisfied, including a maximum bury depth of 3 m, maximum bury speed of 2 km/h, and maximum forward speed of 1.54 m/s.