Nonlinear Disturbance Observer-enhanced Depth Control for Submarine: A Sum of Squares Technique

摘要

The state feedback control using sum of squares technique (SOStools) combined with the nonlinear observer is applied to the depth control of a submarine. The mathematical model of the submarine is rewritten as the linear-like form, then the uncertainty caused by the variation of the hydrodynamic coefficients is treated as the disturbance, which can be estimated online by a nonlinear observer. The method can provide good robustness against the nonlinearity as well as the uncertainty, which is verified by the simulation.