A New Approach to System Design Optimization of Underwater Gliders

Abstract

System design optimization of an underwater glider involves various disciplines, such as hydrodynamics, structure, sizing, control, power, payload, and trajectory, which overlap with each other and influence the endurance of the system. Compared with traditional optimization methods, multidisciplinary design optimization provides a more efficient method for complex engineering problems involving overlapping disciplines. This article establishes a universal disciplinary framework of an underwater glider after the system analysis, which involves five disciplines, including hydrodynamic shape, pressure hull, buoyancy, attitude, and energy. To decouple the relationship among these disciplines and improve the efficiency of optimization, approximate models in the disciplines of hydrodynamic shape and pressure hull are established. After the coupling analysis, a novel approach is proposed for the system design optimization of an underwater glider, in which the concurrent subspace optimization, penalty function method, and the multipopulation genetic algorithm are combined together. The approach proposed in this article can meet the diversified design requirements of underwater gliders in different observation missions, which is verified by a sea trial of an improved Petrel-L glider.