Effectiveness Comparison of Selected 3D Tracking Controllers for Underactuated UUVs with Small Displacement of Mass Center

This work is devoted a particular trajectory tracking problem of underactuated unmanned underwater vehicles (UUVs) with model reduced to five degrees of freedom (DOF). Such a model is quite widespread in the literature and used to describe the dynamics of UUVs. On this basis, various control strategies are designed, such that the closed-loop system track the trajectory with assumed accuracy. Unfortunately, the main drawback of this approach is that the presented results relate to the situation when the center of the mass is the same as the geometric center-point. Several algorithms have been selected for testing the control effectiveness (one based on the model with shifted center of the mass and other four based on the assumption that this center is in the same place as the geometric center). The goal of the paper is to check whether the correction mechanisms contained in the controller ensure the implementation of the trajectory tracking task. Simulation results on the five-DOF vehicle model show performance of the considered control schemes in the presence of a small shift of the mass center.