Sensitivity analysis of submersibles’ manoeuvrability and its application to the design of actuator inputs

The influences of hydrodynamic coefficients on the prediction of manoeuvrability were examined by sensitivity analysis (SA) of direct method. The equations of motion used were the standard equations of motion for submarine [Gertler, M., Hagen, G.R., 1967. Standard equations of motion for submarine simulation. DTNSRDC Report], and three submersibles with different appendages were considered. Numerical simulations of three types of sea trials are performed to obtain the sensitivities of motions to hydrodynamic coefficients. Since the accuracy of hydrodynamic coefficients’ estimates is increased by the use of sensitivity-maximizing inputs, the sensitivity-optimal actuator commands that are sequences of bang-bang type inputs were deduced with genetic algorithm (GA) optimization technique.