Pitching damping control analysis for optical stability and motion blur reduction of avian monitoring barges in coastal water
Small barges used for remote avian monitoring in coastal aquaculture farms suffer from pitching motions induced by waves, which cause camera motion blur and degrade object identification rates. This study aims to control the free motion of the barge to ensure the stability of camera images and mitigate motion blur. To maintain the reliability of high-resolution images (dynamic MTF of 0.9 or higher), the allowable pitching angular velocity was calculated as 0.415 deg/s. Computational fluid dynamics (CFD) was utilized to analyze the hull responses according to wave heights (0.1-0.3 m) and wave periods (2-4 s), and to evaluate the control performance of a linear damping system. Without the damper, the maximum angular velocity reached 2.908 deg/s under short-period (2 s) extreme waves, exceeding the allowable limit. When the damper was applied, the angular velocity was suppressed to 0.408 deg/s even under the same harsh conditions, satisfying the target criterion. It was confirmed that as the period increased, the control stability further improved, securing an overwhelming margin of safety against external disturbances. The damping system effectively absorbs vibrations that cause motion blur and can be a practical alternative to enhance the optical stability of remote aquaculture monitoring systems.