Omnidirectional Motion Trajectory Tracking Control Method for AUVs

The precise trajectory tracking capability of autonomous undersea vehicles(AUVs) is crucial for completing underwater tasks such as exploration, obstacle avoidance, and pipeline inspection. However, AUVs are typically underactuated systems that satisfy non-holonomic dynamic constraints, and they cannot track some specific trajectories or perform some specific underwater maneuvers, such as station-keeping U-turns and point-circling observations. Most researchers focus on improving the trajectory tracking capability of AUVs based on underactuated system theory. This paper, however, proposed a new omnidirectional motion trajectory tracking control method for AUVs from the perspective of structural improvement, drawing on the configuration design of remotely operated vehicles(ROVs). The method retained the original low-drag streamlined torpedo-like structural design and motion mode of AUVs while endowing them with a new omnidirectional motion mode. Using the Bluefin series AUV as an example, the paper designed and modified the omnidirectional motion structure and developed a trajectory generation algorithm based on the Hermite algorithm, a trajectory guidance algorithm based on the scaling factor, and a sailing-heading hybrid control algorithm. Both simulation and underwater experiments validate the control method. The results show this method can achieve omnidirectional navigation, solve motion constraint problems in AUV trajectory tracking, enable them to track any trajectory, and complete specific underwater maneuvers.