Onboard artificial stable platform system free from roll and pitch motions

This paper aims the development of an onboard artificial stable platform (ONASP) which is free from ship's rolling and pitching, using an improved Stewart type of parallel link driven by a small high accurate oil pressure pump, called direct drive volume (DDV) system. In this system, the inverse kinematic solutions to cancel the actual ships' rolling and pitching and in order to compensate time delay between the motions of platform and the ships' rolling and pitching, a predictive auto regressive model of object ship for the rolling and pitching are applied. In the paper, one simulator using the actual ONASP system is built in a laboratory and it is confirmed that an artificial stable platform to cancel roll and pitch motions of a small training ship can be realized. Lastly, this system is applied for making a stable platform free form rolling and pitching on the actual ship. Copyright (C) 2001 IFAC.