Three-dimensional configuration optimization of X semi-dynamic rudder for fully appended AUV based on response surface methodology and NSGA-II

A novel three-dimensional (3D) configuration method is proposed for the X semi-dynamic rudder (XSDR) design of a fully appended autonomous underwater vehicle (AUV), which realizes the balanced optimization of the maneuverability of the AUV and the efficiency and effectiveness of the XSDR. The XSDR is defined by twenty-one geometric parameters of the teardrop profile and quadrilateral profile, in which the teardrop profile is parameterized by the Bézier-PARSEC method. Seven key parameters of XSDR that significantly impact the hydrodynamic performance indices of XSDR and fully appended AUV are selected by the Plackett-Burman Design (PBD) method. Then, response surface methodology (RSM) comprehensive evaluation models are developed using the Box-Behnken design (BBD) method to elucidate the relationship between seven key parameters and two weighted metrics. These weighted metrics, which represent the hydrodynamic performance of XSDR and AUV, are derived using the analytic hierarchy process (AHP) and the entropy method . Therefore, a balanced optimization model is proposed and solved by the non-dominated sorting genetic algorithm II (NSGA-II) based on local density entropy. The results indicate that when the compromise points of the two weighted metrics are selected from the range of values within the Pareto frontier solution set, the weighted metrics of the AUV improve by 59.28 % and 51.55 %, while those of the XSDR improve by 28.40 % and 30.87 %. • The 3D configuration of X semi-dynamic rudder for AUV is optimized using a method that combines RSM and improved NSGA-II. • The X semi-dynamic rudder's parameterization considers both the teardrop and quadrilateral profile parameters. • A comprehensive evaluation method for X semi-dynamic rudder is proposed. • The validity of the simulation model is verified by measured AUV test data and public test data (SUBOFF_HSCR). • The methodology provides effective tools and guidance for rudder design and hydrodynamic simulation of AUV.