Nonlinear Observer Design for a Robotic Unmanned Surface Vehicle Using GPS and IMU Measurements with Experimental Results

This paper considers the state estimation problem of a robotic unmanned surface vehicle by using Global Positioning System (GPS) and inertial measurement unit (IMU) measurements. Firstly, the kinematic strapdown equations are developed for marine vehicles based on the experimental platform. Then, two nonlinear observers are proposed to estimate the position and velocity information of marine vehicles via loosely coupled GPS/IMU integration. One is based on the measurements of the position, velocity and acceleration, and the other is based on the measurements of the position and acceleration. For both nonlinear observers, the origin of the closed-loop systems are shown to be globally asymptotically stable. Finally, the results of simulations and experiments are given to verify the effectiveness of the two nonlinear observers.