Separation motion's security of autonomous underwater vehicle

In order to provide theoretical basis for selecting an autonomous underwater vehicle's (AUV's) separation mode from the load's gravity release mode and the push-thrust separation one, the separation motion's security of AUV was analyzed quantitatively. According to the differences of interaction between load and carrier, kinetic equations of AUV's separation motion in the two modes were derived by using multi-rigid body mechanics principle. The separation motion's security model was proposed based on the shortest distance measurement between load and carrier after separating them thoroughly. The results show that, when load's gravity is greater than its buoyancy, separation motion's security increases with increasing initial separation velocity or accessional thrust force and decreases while the set separation angle is too large or too small for the former mode; for the latter mode, the separation motion's security is higher than that of the former mode at low initial separation velocity and strong thrust force, the high initiation velocity can lead to collision.