Energy shaping for stably coordinating internally actuated underwater vehicles

This paper considers the problem of stabilization and coordination for underwater vehicles using internal moving mass actuators. The underwater vehicle (UV) is modeled as a neutrally buoyant, bottom-heavy, submerged rigid body in an ideal fluid. The force of interaction between the UV and internal moving mass destabilizes UV´s steady translation along its long axis if the moving mass is allowed to move freely inside the UV body. However, this interaction force can also be treated as a control input. Energy shaping is applied to control the motion of moving mass relative to the UV body such that the UV´s steady long axis translation with a designated attitude is stabilized. The proposed method is extended to design control laws to coordinate steady motions of multiple UVs.