Nonlinear Observer with Time-Varying Gains for Inertial Navigation Aided by Satellite Reference Systems in Dynamic Positioning

Abstract

The measurement quality of Global Navigation Satellites Systems (GNSS) during marine operations will vary over time. Inherently, GNSS quality changes should be handled when GNSS is utilized as aid in inertial navigation systems. In this paper we present an observer for estimating position, velocity and attitude with time-varying gains for high performance sensor fusion based on GNSS quality and other quality indicators. The origin of the error dynamics is proven to be uniformly semiglobal exponentially stable. The concept is illustrated by simulating a vessel operating in dynamic positioning with GNSS and inertial sensors.