Design of landing trajectory for unpowered aircraft using an hp-adaptive Radau pseudospectral method

Aiming at the problem of an emergency landing of unpowered aircraft, this paper presents the design of landing trajectory. Firstly, the effect of the shear wind for the flight path is considered. Secondly, the problem of unpowered flight's landing is modeled by the time-optimal control method. The landing trajectory is divided into four piecewise trajectories and the characteristics of each are determined by some simple equations. The deflection angle of turn is obtained by the Dubins curves method. Thirdly, the problem is solved by the hp-adaptive radau pseudospectral method. Simulation results indicate that the designed landing trajectory could guide the unpowered plane landed safely and quickly.