Design of a prototype ocean current turbine - Part II: flight control system

This paper presents and compares control strategies for the 1/30th scale C-Plane prototype, an ocean current turbine under development at FAU. The C-Plane is a hydrodynamic platform that is tethered to the sea floor and uses sustained ocean currents to produce electricity. This turbine uses its wingtips and canard to control its depth and orientation so that it can maximize energy production while flying in a temporally and spatially varying current. Three different control systems are developed and compared in this paper using the mathematical model and dynamics simulation developed in the companion paper. These control approaches each use three sub-modes of operation (ascending, descending, and steady) and are the Mixed PID/Bang Bang (MPID), Mixed LQR/PID/Bang Bang (MLQR), and Mixed LQG/PID/Bang Bang (MLQG) control approaches. All three controllers are effective and were to control the C-Plane under expected operating conditions. The MPID controller proved to be slightly more effective and robust. (C) 2005 Elsevier Ltd. All rights reserved.