Kinematical control of motion of underwater vehicle in horizontal plane

Abstract

In the paper presented is a method of designing a fuzzy-logic-based autopilot for control of horizontal motion of an unmanned underwater vehicle. The control system's synthesis was performed under the assumption that the vehicle can move with variable linear and angular velocities and the quantities possible to be measured are: position and orientation of the vehicle in the inertial reference system. The task of the autopilot was to minimize the mean squares of deviations from the motion trajectory given in the form of a broken line defined by the coordinates of successive turning points. To generate control signals three independent fuzzy PD controllers using the control principles based on the Mac Vicar-Whelan's standard base, were applied. For the linguistic variables of each controller appropriate fuzzy sets were selected and linear membership functions of trapezoidal and triangular form were defined. The presented results of the simulation tests performed for the remotely operated underwater vehicle „Ukwiał", with and without influence of disturbances resulting from sea current, confirm the proposed approach to be correct and effective.