Exploring feasibility of low altitude penetration of high-altitude long-distance gliding UUV (unmanned underwater vehicle)

The technology of high-altitude long-distance gliding UUV is an integration of high-altitude volplane and underwater voyage and the trajectory of low altitude penetration is an important part of the whole trajectory of highaltitude long-distance gliding UUV. Sections 1 through 3 explain the feasibility exploration mentioned in the title, whose core consists of: "By establishing the six-degrees of freedom motion equations of the UUV, the ballistic simulation and detailed analysis of the trajectory of the low altitude penetration are accomplished. Adopting the conventional constant altitude control scheme, the simulation results in section 2 illustrate that low altitude penetration cannot be achieved, due to excessive fall height, even below the ground plane. In order to avoid this phenomenon, two methods applied to resolve this problem respectively are utilizing limit rudder angle in the low altitude penetration (subsection 3.1) and rewriting the control equation over height (subsection 3.2). " The simulation results, given in Figs. 5 through 12, and their analysis show preliminarily that both of the two methods can indeed suppress the problems significantly; besides, the second one has better applicability and the system is relatively more stable.