INTEGRATION OF GPS/INS/VISION SENSORS TO NAVIGATE UNMANNED AERIAL VEHICLES

摘要

This paper presents an integrated GPS/INS/Vision navigation system for Unmanned Aerial Vehicles (UAVs). A CCD (Charge-Coupled Device) video camera and laser rangefinder (LRF) based vision system, combined with inertial sensors, provides the information on the vertical and horizontal movements of the UAV (helicopter) relative to the ground, which is critical for the safety of UAV operations. Two Kalman filers have been designed to operate separately to provide a reliable check on the navigation solutions. When GPS signals are available, the GPS measurements are used to update the error states in the two Kalman filters, in order to estimate the INS sensors, LRF and optic flow modelling errors, and provide redundant navigation solutions. With the corrected measurements from the vision system, the UAV's relative movements relative to the ground are then estimated continuously, even during GPS signal blockages. The modelling strategies and the data fusion procedure for this sensor integration scenario are discussed with some numerical analysis results, demonstrating the potential performance of the proposed triple integration.