• 한국산업정보학회논문지
• /
• 제19권4호
• /
• pp.65-72
• /
• 2014

제조기업의 생산성을 높이기 위해서는 생산현장에서 발생하는 다양한 손실에 대한 분석 및 개선이 필요하다. 본 논문에서는 비가동 손실 분석을 위하여 기존에 구축한 생산현장 정보 수집 시스템을 활용한 설비/공정의 비가동 시간 수집 및 분석에 대하여 소개한다. 비가동 시간, 원인을 수집하기 위하여 생산현장 모니터링 정보, 사용자 등록 비가동 이벤트, 설비 고장진단 알고리듬, 작업자 입력을 활용하였다. 또한 수집된 비가동 시간의 분석을 수행하기 위한 웹 기반의 사용자 인터페이스를 개발하였다. 부품가공기업의 시범 적용을 통하여 시스템의 유용성을 확인하였다.

• Smart Structures and Systems
• /
• 제13권2호
• /
• pp.177-201
• /
• 2014

With the increased size and flexibility of the tower and blades, structural vibrations are becoming a limiting factor towards the design of even larger and more powerful wind turbines. Research into the use of vibration mitigation devices in the turbine tower has been carried out but the use of dampers in the blades has yet to be investigated in detail. Mitigating vibrations will increase the design life and hence economic viability of the turbine blades and allow for continual operation with decreased downtime. The aim of this paper is to investigate the effectiveness of Semi-Active Tuned Mass Dampers (STMDs) in reducing the edgewise vibrations in the turbine blades. A frequency tracking algorithm based on the Short Time Fourier Transform (STFT) technique is used to tune the damper. A theoretical model has been developed to capture the dynamic behaviour of the blades including the coupling with the tower to accurately model the dynamics of the entire turbine structure. The resulting model consists of time dependent equations of motion and negative damping terms due to the coupling present in the system. The performances of the STMDs based vibration controller have been tested under different loading and operating conditions. Numerical analysis has shown that variation in certain parameters of the system, along with the time varying nature of the system matrices has led to the need for STMDs to allow for real-time tuning to the resonant frequencies of the system.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1137-1140
• /
• 2005

Automatic welding has been used frequently on pipeline projects. The productivity and reliability are most essential features of the automatic welding system. The mechanized GMAW process is the most widely used welding process and the carriage and band system is most effective welding system for pipeline laying. This application-oriented paper introduces new automatic welding equipment for pipeline construction. It is based on cutting-edge design and practical welding physics to minimize downtime. This paper also describes the control system which was designed and implemented for new automatic welding equipment. The system has the self diagnostic function which facilitates maintenance and repairs, and also has the network function via which the welding task data can be transmitted and the welding process data can be monitored. The laser vision sensor was designed for narrow welding groove in order to implement higher accuracy of seam tracking and fully automatic operation.