Fuzzy logic PID based control design and performance for a pectoral fin propelled unmanned underwater vehicle

This paper describes the modeling, simulation, and control of a UUV in six degree-of-freedom (6-DOF) motion using two NRL actively controlled-curvature fins. Computational fluid dynamic (CFD) analysis and experimental results are used in modeling the fin as part of the 6-DOF vehicle model. A fuzzy logic proportional-integral-derivative (PID) based control system has been developed to smoothly transition between preprogrammed sets of fin kinematics in order to create a stable and highly maneuverable UUV. Two different approaches to a fuzzy logic PID controller are analyzed: weighted gait combination (WGC), and modification of mean bulk angle bias (MBAB). Advantages and disadvantages of both methods at the vehicle level are discussed. Simulation results show desirable system performance over a wide range of maneuvers.