Design of a UV with Adjustable Thruster Orientations and SA-SQP-Based Thruster Orientation Optimization

The uncertainties of underwater environments pose challenges to the stable operation of underwater vehicles (UVs). Disturbances such as waves and currents in the environment, coupled with the actuator fluid factors, introduce non-negligible disturbances in the six degrees of freedom, which significantly affect the stability of the UV and limit its maximum available operating force. To address these challenges, this article proposes a dynamic UV actuator configuration using eight thrusters, each with two additional degrees of freedom. Combined with simulated annealing and sequential quadratic programming (SA-SQP) optimization algorithms, the system allows real-time adjustment of the thruster direction to adapt to various scenarios. Compared with traditional thruster configurations, it provides greater thrust reserve and maneuverability. The proposed approach overcomes the limitation of traditional vector propulsion systems, which have insufficient torque in some poses. Simulations show that the design achieves, on average, twice the maximum torques in all directions compared to the reference configuration. Real-world experiments demonstrate that modifying the objective function of the SA-SQP algorithm to prioritize specific directions improved the surge force by 25%, and the pitch torque by 18%.