In Situ Damping Parameter Estimation for an Underwater Vehicle Using Onboard Sensors*

Abstract

In underwater vehicle navigation, accurate model parameters are crucial for the development of control and localization algorithms. However, the identification of hydrodynamic parameters is nontrivial, and experimental evaluation is usually required for accurate determination. Since the vehicle configuration is not unique and may change between missions, identification methods are needed that allow fast estimation of vehicle parameters in the field shortly before the start of a mission. In this work, we investigate the estimation of translational damping parameters for an underwater vehicle using onboard sensor measurements from self-propelled experiments. To improve the estimation of body forces, we have augmented the thruster model to consider decreasing battery voltage and hydrodynamic performance loss. Furthermore, we conducted field tests with an underwater vehicle equipped with an acoustic modem as well as an RTK-GNSS reference system to investigate the fast identification of surge damping parameters. The experimental results show that with the fitted damping model, the steady-state velocities in the range of 0. 4m/s to 0.85 m/s are predicted with an error less than 0.05 m/s.