Research on the Rolling Motion Mode of a SWATH-USV

Abstract

This paper takes a SWATH-USV as the research object, and carries out a series of static water roll attenuation tests under different drafts and different initial roll angles. In order to study the roll motion mode of the SWATH-USV, we have established three mathematical models of the roll motion mode, and written the system identification software in C# language, based on the system identification theory and the genetic programming algorithm. Firstly, by calculating the predicted values of angular velocity under different drafts and different initial roll angles, the error between the test value and the fitted value was analyzed, and the consistency between the predicted value and the test result was found to be good, which proves the reliability of the system identification software. Secondly, through the further processing of the test data, the variation law of the torque coefficient affecting the rolling motion with the draft and the initial roll angle is preliminarily analyzed. Finally, the polynomial response surface method is applied to fit the equation containing the rolling hydrodynamic torque coefficient and the recovery moment coefficient, and the equation is found to be applicability. The analysis results and methods can provide reference for the study of the wave resistance of such USV, and provide important technical support for the subsequent optimization of the boat type.