Deriving a six-dimensional mathematical model of an unmanned underwater vehicle motion control system with interval parameters

The paper is dedicated to a problem of mathematical modeling of a motion control system for unmanned underwater vehicle. The proposed model considers interval parametric uncertainty of underwater vehicle itself and water environment, nonlinearity of control object and actuator of the system and interaction between its control channels. In order to derive the model several objectives were accomplished: a mathematical model of underwater vehicle motion in a viscous fluid in all six degrees of freedom was derived; mathematical model of separate thruster and whole propulsion and steering system was derived; both model were linearized with the help of interval linearization method and, finally, a structure of the whole motion control system was determined. The model is applicable for simulation modeling of underwater vehicle motion and for analysis and synthesis of motion control systems in condition of interval parametric uncertainty.