Fuzzy Depth Control of Small Cylindrical Object Navigating near Free-Surface

Small cylindrical object navigating near free-surface is subject to wave disturbance. Wave disturbance can dramatically influence the depth control of the near-surface navigating object. A self-regulating fuzzy depth control method is proposed to keep the small cylindrical object navigate at the expected depth under free-surface disturbance. The near-surface dynamic model of the cylindrical object is presented and the fuzzy depth control method is modeled. The results obtained by a series of hardware-in-loop simulations demonstrate that the self-tuning fuzzy depth control method is valid to keep the small cylindrical object navigate steadily in the expected depth under free-surface disturbances.