A Study of the Shaft Power Measuring System Using Cameras

J. Ocean Eng. Technol. 2010;24(4):72-77.

Jeong Jeong-Soon,Kim Young-Bok,Choi Myung-Soo

Department of Mechanical and Control Engineering Graduate School of Pukyong National University,Department of Mechanical System Engineering Pukyong National University,Department of Maritime Police Science Chonnam National University

카메라를 이용한 축계 비틀림 계측 장치 개발

정정순,김영복,최명수

부경대학교 대학원 제어기계공학과,부경대학교 기계시스템공학과,전남대학교 해양경찰학과

Keywords: Torsional angle, Torsional load, Shaft power measurement, Camera, vision sensor, Monitoring system

핵심용어: 비틀림 각, 비틀림 하중, 축동력 측정, 카메라, 비전 센서, 모니터링 시스템

Abstract

This paper presents a method for measuring the shaft power of a marine main engine. Usually, in traditional systems for measuring shaft power, a strain gauge is used even though it has several disadvantages. First, it is difficult to set up the strain gauge on the shaft and acquire the correct signal for analysis. Second, it is very expensive and complicated. For these reasons, we investigated alternative approaches for measuring shaft power and proposed a new method that uses a vision-based measurement system. For this study, templates for image processing and CCD cameras were installed at the both ends of the shaft. Then, in order for the cameras to capture the images synchronously, we used a trigger mark and a optical sensor. The position of each template between the first and the second camera images were compared to calculate the torsion angle. The proposed measurement system can be installed more easily than traditional measurement systems and is suitable for any shaft because it does not contact the shaft. With this approach, it is possible to measure the shaft power while a ship is operating.