Coordinated landing control of Unmanned Aerial Vehicle

The automatic landing control coordinating the Three-Dimensional (3D) position and 3D attitude with strong robustness and high precision is proposed for Unmanned Aerial Vehicle (UAV). The generalized landing trajectory including 3D position and 3D attitude is designed based on the optimization of the steady landing condition to guide the landing. The Altitude and pitch angle are quasi-decoupled by Direct Force Control (DFC), and lateral distance deviation, roll angle and yaw angle are coordinated taking the advantage of the lateral control which combines the roll motion and yaw motion with variable roll angle restriction and yaw angle restriction. The flight experiments under strong wind show the UAV could track the generalized landing trajectory robustly and touch the ground with high precision and security.