조화기진력에 의해 발생하는 구조물 진동 억제를 위한 지능형 진동보상기 개발

Abstract

The structure of a ship is inevitably subjected to vibrations caused by many excitation sources, such as the engine, the propeller, and sea waves. Moreover, the natural vibration characteristics of a ship tend to vary owing to the loading and operating conditions. Over recent years, given the decreasing weights of hulls and the increasing speeds of engines, the possibility of resonance in the structure has increased; this cannot be avoided by changing the structure alone. Hence, a more feasible method of counteracting the engine or propeller excitations needs to be developed. In this study, a vibration compensator comprising an unbalanced mass and a motor is considered as the counteracting actuator. The vibration compensator must be operated with the optimal phase relative to the engine or propeller excitations, in order to minimize the effect of the disturbance. To this end, an algorithm that can effectively and stably determine the optimal phase was developed, thus essentially resulting in an intelligent vibration compensator. The control performance of the proposed intelligent vibration compensator was verified both theoretically and experimentally. The theoretical and experimental results indicate that the vibrations caused by harmonic disturbances can be suppressed effectively.