System Identification for the Hammerhead Autonomous Underwater Vehicle

Abstract

Autonomous underwater vehicles are designed by oceanic engineers to help them
perform numerous duties that could bee too dangerous, time consuming or expensive for human
to do. Operating this vehicle requires a thorough preparation to avoid costly technical problems
which may happen in the middle of a critical or life threatening mission. Capturing the
dynamics of a vehicle and expressing it in mathematical equations are paramount, but proved to
be an intricate task as a result of nonlinearity in vehicle dynamics and the degrees of freedom of
vehicle movement. Certain hydrodynamic parameters for a vehicle model can be determined
analytically. However, other parameters will need to be identified using scaled model or full
tank test. To compensate this, an alternate route using system identification methods can be
used. The methods are quite effective in providing reliable and accurate models based only on
input-output data obtained from vehicle trials. For the Hammerhead vehicle, the benefits
offered by the methods are quite desirable and therefore utilized throughout vehicle
development stages.