Security of AUV's separation motion in two separation modes

An autonomous underwater vehicle (AUV) consists of load and launcher. We adopt two separation modes: Mode 1 using thrust force between load and launcher and Mode 2 using load's gravity. Considering the interaction between load and launcher in the course of separation motion, we derive the equations of motion for the multi-rigid body. We establish a security model for separation motion and then we derive eq. (8) in the full paper for calculating the minimum distance Ω between load and launcher after complete separation. We also discuss quantitatively the influence of the minimum distance on the security of AUV's separation motion in Mode 1 and Mode 2 respectively. The discussion results, shown in Figs. 4 and 5 and Tables 1 and 2 in the full paper, indicate preliminarily that, under the condition that the launcher has positive buoyancy and no control, collision is avoidable in Mode 1, and the separation security in Mode 1 is higher than that in Mode 2 under certain conditions.