Experimental investigation of T-foil hybrid control strategy for ship motion reduction in head seas

Abstract

A hybrid control strategy is proposed to control the T-foil, which can significantly increase the sea-keeping performance of a high-speed trimaran. The strategy includes a gain, which can adjust the maximum flap angle according to the real-time vessel motion response. To investigate the performance of the hybrid control strategy, experimental tests were conducted in a towing tank. The trimaran model with an active control T-foil was tested in head seas with various wave lengths at two forward speeds. The trimaran's heave, pitch, and local acceleration were measured and compared among four control strategies (passive, linear, step, and hybrid control). It is found that the hybrid control strategy can effectively reduce the motion response of the trimaran in the entire range of the wave lengths, and shows better adaptability than the other control strategies.