Abstract:In order to accurately control the vertical movement of the profiling float, a variable volume oil bladder buoyancy regulation system that can precisely control the oil volume is proposed, which includes components such as an external oil bladder, a pressurized oil tank, solenoid ball valves with good sealing performance and a hydraulic pump with adjustable speed. The draw-wire displacement sensor is used to collect the liquid level position of the pressurized oil tank in real time to achieve oil volume monitoring and high-precision closed-loop feedback control of the volume of the external oil bladder. By designing a hydraulic system with extremely low leakage, the buoyancy of the system can be stabilized for a long time in the standby mode. In order to accurately control the buoyancy regulation system, a mathematical model of the control system is constructed, a Proportional Integral Differential (PID) control algorithm is introduced, and the stability simulation is carried out by Simulink. The test results show that the system can achieve precise control of buoyancy with a maximum overshoot of less than 1%. The stability and response speed are in line with expectations, which verifies the reliability of the control strategy.