Design and Control of High Precision Buoyancy Adjustment System for Small AUVs

This paper addresses the issue of buoyancy variation caused by differences in seawater density at varying operational depths for small AUVs working within 200 meters. To tackle this, a buoyancy adjustment system is designed that uses a piston-type oil cylinder to take in and release oil. The system integrates a digital-to-analog converter with a cable sensor to achieve precise measurement and control of the oil volume by accurately measuring the piston position. A mathematical model of the buoyancy adjustment system is established, and a fuzzy PID control strategy optimized by the Beetle Antennae Search (BAS) algorithm is proposed. Through Simulink simulation analysis, the system's precision adjustment capability and stability are validated. The simulation results demonstrate that the system exhibits good control performance in terms of adjustment time, overshoot, and disturbance rejection, thereby proving its reliability and feasibility.