Variable Structure Control Algorithm based on Navigation Coordinate System for UAVs Path Following

This paper considers the problem of unmanned air vehicles (UAVs) path following in two-dimensional. To ensure the correct output of lateral deviation and heading angle, a dynamic navigation coordinate system based on the route points is defined, two mathematical models are established respectively for straight-line paths and circular-orbit paths, proper sliding mode and sliding approach guidance law are designed by variable structure control theory. Simulation result demonstrates the algorithm can effectuate the whole close-loop path following in wind environment with the advantages of easy-realized and timely.