Aiming at the problem of underwater depth control of deep-sea profileing buoy

a method of fixed depth buoyancy control method based on ADRC is proposed. Aiming at the underwater motion characteristics of the deep-sea profiling buoy

a vertical motion controller based on ADRC is designed. According to the buoyancy adjustment mechanism of the buoy

the movement process of the buoy is analyzed

and the movement model for the buoy is established. Aiming at the nonlinear and strong coupling characteristics of the model

ADRC is used to realize the decoupling control of multivariable system. An extended state observer（ ESO） is used to estimate the uncertainties and external disturbances of the model

and dynamic feedback compensation is carried out in real time. The simulation results show that the designed tracking controller can overcome the influence of uncertainties and external interference in model

quickly establish steady state

and has good robustness and control performance.