A high fidelity simulation for vertical planar motion control of underwater vehicle navigating near surface waves using joint mechanism control

Abstract

Traditional underwater vehicle (UV) motion control simulations primarily rely on dynamic modeling but often neglect the precise consideration of fluid forces, such as turbulence effects, viscous phenomena, and flow separation. To address this limitation, this study focuses on UV operations near the water surface and embeds a vertical plane integrated control strategy, combining Line-of-Sight Proportional–Integral–Derivative (LOS-PID) rudder angle control and ballast weight control, within a Computational Fluid Dynamics (CFD) framework. This approach achieves precise depth maintenance and pitch stability. The primary contributions of this research include the following three aspects: (1) A novel high-fidelity motion simulation framework is proposed via coupling closed loop motion control algorithms within CFD to study the UV navigating near surface waves. (2) The sea state and water depth affect the surfacing behaviors of UV during low-speed navigation near the surface waves. The second order waves cause the surfacing velocity to become faster when the UV is going up, consequently bringing control difficulty. (3) A comparative analysis of different control strategies shows that the stern rudder control is unable to overcome the second-order wave induced motion while the joint mechanism (rudder and ballast) control demonstrates effective suppression of surfacing behavior of UV navigating near surface waves. This integrated motion simulation framework provides a robust approach for investigating the control and simultaneous fluid mechanic behaviors of UVs in complex oceanic environments.