트랙기반 중작업용 ROV에 적용 가능한 어라운드 뷰 소나 및 굴착깊이 측정 소나 성능 검증에 관한 연구

A study on the performance verification of an around-view sonar and an excavation depth measurement sonar application to ROV for track-based heavy works

Abstract

본 논문은 트랙기반 중작업용 ROV(Remotely Operated underwater Vehicle)에 적용 가능한 어라운드 뷰 소나 및 굴착깊이 측정 소나의 성능 검증에 대한 내용을 다루고 있다. 현재 국산화 개발 중인 중작업용 ROV에 활용 가능한 어라운드 뷰 소나 및 굴착깊이 측정 소나를 장착하여 수조 및 실해역에서 성능 검증 실험을 수행하였다. 어라운드 뷰 소나의 경우 이미지 소나를 ROV 전후좌우 4방향에 장착하고, 굴착깊이 측정 소나는 멀티 빔 음향측심기(Multi Beam Echo Sounder, MBES) 기술로써 ROV 전방에 장착된다. 본 논문에서 개발한 소나를 장착하고 ROV를 실해역에 진수시켜 소나를 운용한 결과 소나 시스템들은 작업 중 발생하는 침전된 부유물이 발생하거나 탁도가 높은 해역에 영향을 거의 받지 않으며 어라운드 뷰 소나의 경우 ROV 전방 30 m 거리에 있는 암반지형, 자갈, 모래톱 등을 확인할 수 있었다. 그리고 굴착깊이 측정 소나의 경우 ROV가 굴착 작업을 수행 후 굴착 깊이를 측정 가능함을 확인하였다. 본 논문에서 제안한 어라운드 뷰 소나와 굴착깊이 측정 소나를 활용함으로써 작업효율성을 높일 수 있음을 입증하였다.

In this paper, the performance verification of an around-view sonar and an excavation depth measuring sonar applicable to track-based ROVs (Remotely Operated underwater Vehicles) for heavy duty work is studied. For the performance verification, an experiment is carried out in a water tank and at sea by attaching the around-view sonar and the excavation depth measuring sonar for a heavy work ROV. In the case of the around-view sonar, image sonars are mounted on ROV in four directions (front, back, left and right) and in the case of the excavation depth measuring sonar, the same kind of MBES (Multi Beam Echo Sounder) is mounted on the front of the ROV. The result of an operation test of the ROV equipped with these sonars shows that the sonar systems are rarely affected by high turbidity due to sedimentation during the operation. In the case of the around-view sonar, it is possible to see rock formation, gravel and sandbank 30 m ahead of the ROV. It is confirmed that the excavation depth can be measured after the ROV has performed the excavation. This experiment demonstrates that the ROV can improve the efficiency of the work by utilizing the around-view sonar and the excavation depth measuring sonar.

Fig. 1. Environment of ROV test underwater.

Fig. 2. Installed ROV around-view sonar & excavation depth measurement sonar (a: image sonar, b: multi-beam echo sounder).

Fig. 3. Diagram of around-view & excavation depth measurement sonar.

Fig. 4. Examples of image sonar principles.

Fig. 5. Concept of operating image sonar.

Fig. 6. Sample of around-view sonar image (barge).

Fig. 7. Concept of excavation depth measurement sonar.

Fig. 8. Concept of excavation depth measurement sonar.

Fig. 9. Sample of excavation depth measurement sonar.

Fig. 10. Concept of around-view sonar test in water tank.

Fig. 11. Result image of around-view sonar test in water tank.

Fig. 12. Concept of maximum excavation depth measurement test in water tank.

Fig. 13. Result image of maximum excavation depth measurement test in water tank (2D & 3D).

Fig. 14. Shoal seabed image of around-view sonar.

Fig. 15 Rocky & pebble seabed image of around-view sonar.

Fig. 16. Rocky & pebble seabed image of around-view sonar (excavation area).

Fig. 17. ROV slip image of around-view sonar.

Fig. 18. Excavation seabed image of excavation depth measurement sonar (2D, width, height measurement).

Fig. 19. Excavation seabed image of excavation depth measurement sonar (3D).