Experimental Study of the Motion Response of a Bionic Manta Ray Vehicle Model under Regular Wave

The wave buoy analogy is mostly applied to ships, while its application in manta ray bionic vehicles is less frequently addressed. However, the vehicle needs to obtain wave direction information to adjust its own attitude when operating on the ocean surface. This study discusses a method for obtaining current main wave direction information for a manta ray bionic vehicle. Systematic wave tank experiments were performed to examine the relationship between the pitch, roll, and wave incidence direction of the vehicle. One of the important results is that the phase difference in the roll and pitch motion of the manta ray vehicle model at 30 and 60 degrees headings is very similar, while at 120 and 150 degrees, they are in anti-phase. Another result is that the directional parameter curve calculated from the power spectrum of the rolling and pitching motion time series data is symmetrical about a 90-degree wave direction. The conclusion of this study is that the manta ray bionic vehicle has excellent wave-following performance and can obtain information about the current main wave direction through the relationship between its roll and pitch movements and the relative incident wave direction.