Spiral Landing Trajectory and Pursuit Guidance Law Design for Vision-Based Net-Recovery UAV

Abstract

This paper deals with spiral landing trajectory and terminal landing guidance law for a net-recovery landing of a fixed-wing UAV(Unmanned Aerial Vehicle). The net-recovery landing flight is divided into two phases. In the first phase, a spiral descending path is designed from any initial position to a final approaching waypoint toward a recovery net. The flight path angle of the UAV is controlled to be aligned to the approaching direction at the end of the spiral descent. In the second phase, the aircraft is directly guided from the approaching waypoint to the recovery net with a pseudo pursuit landing guidance law. Sequential imaginary landing and approaching points are generated using a cubic polynomial in the pseudo pursuit landing guidance law. Therefore, the UAV at high altitude with any heading angle can spiral down toward the recovery net without loitering and can fly into the recovery net smoothly. Six degree-of-freedom numerical simulation is performed to verify the performance of the spiral descent path and pseudo pursuit guidance law. Nomenclature α = angle of attack β = angle of sideslip γ = flight path angle a δ = aileron deflection angle e δ = elevator deflection angle r δ = rudder deflection angle A η = heading angle of aircraft ,0 c