An Augmented State Vector Approach to GPS-Based Localization

Abstract

The ANSER project (Airport Night Surveillance Expert Robot) is described, exploiting a mobile robot for autonomous surveillance in civilian airports and similar wide outdoor areas. The paper focuses on the localization subsystem of the patrolling robot, composed of a nondifferential GPS unit and a laser rangefinder for map-based localization (inertial sensors are absent). Moreover, it shows that an augmented state vector approach and an Extended Kalman filter can be successfully employed to estimate the colored components in GPS noise, thus getting closer to the conditions for the EKF to be applicable.