A Robust Impulsive Control Strategy of Supercavitating Vehicles in Changing Systems

Abstract

Supercavitation is a hydrodynamic phenomenon in which an underwater body is almost entirely inside the cavity wall. Since the density of the gas is much lower than that of water, skin friction drag can be reduced considerably. We develop controllers to control a supercavitating vehicle, which is a high-speed vehicle with a cavitator at its nose. We designed controllers based on impulsive inputs, which are used to change the pitch of the vehicle slightly. This slight pitch change is desirable, since a large pitch change can lead to instability of the vehicle due to large planing force. Moreover, our impulsive controllers are robust to disturbances. In practice, the vehicle consumed its fuel to move forward. This fuel consumption led to changing parameters of the vehicle, such as mass. To handle this changing system, we used fuzzy impulsive controllers. We ran simulations to verify the effectiveness of our controllers.