Vessel attitude estimation by camera sensors

Vessel attitude is one of the most sensitive information in important operation. For instance, during ship cargo loading or discharge operation an un-accurate estimation of vessel attitude could compromise the safety of the procedure. Ship pith and roll parameters are directly measured by traditional sensors (bubble levels) or indirectly estimated from ship motion monitoring. Also inertial sensors, that provide a continuous attitude information, are actually used in offshore riser monitoring and dynamic positioning systems but not spread in all commercial ships. The aim of the proposed study is to provide vessel roll and pith using a cheap technology just widespread in shipping. This work presents the project of an embedded solution that uses visual information, captured by a consumer camera that “looks” the horizon. The camera system is constrained to the ship hull, while a computer unit is able to detect and track the horizon line, that fall within the image bounds. The paper describes how the horizon’s movements provide pitch and roll angles, furthermore, in order to perform an accuracy analysis, several static tests were carried out.