Graduation date: 2008
Determining the performance characteristics of various ocean wave energy converters (OWEC) has proven to be difficult due to problems replicating a baseline motion profile in the ocean or wave tank to compare these devices. The linear test bed seeks to mechanically simulate the relative linear motion between the active components experienced by a point absorber OWEC in an ocean environment. A gimbal mount allows the active components of a “float” of a point absorber OWEC to be mounted to the machine’s carriage, which is mechanically driven by timing belts. The “spar” portion of the OWEC is mounted to the base of the linear test bed so that as the carriage moves the float vertically, there is relative linear motion between the float and spar. The current control system allows researchers to input a vertical position versus time function to be tracked by the linear test bed.
However, researchers have desired to improve the linear test bed control system by implementing a force control algorithm based on hydrodynamic equations to accurately reproduce the driving force of the ocean wave. With only position control, the linear test bed will use any necessary force to follow that profile, exaggerating the capabilities of the wave especially if the device is electrically loaded. In addition, the hydrodynamic interaction of the OWEC and an ocean wave cannot be reproduced using only a position feedback control system. The linear test bed design, position control system, and a comprehensive presentation of the novel force control system are provided through this thesis work.