Trajectory optimization and control algorithm of longitudinal perch landing assisted by thruster

This paper proposes a concept and optimization results of perch landing of a fixed wing aircraft using thrusters. Unlike previous researches in perch landing, which can only be applied to small and light vehicles such as MAV, the proposed method can be applied to general size UAV due to usage of thrusters. Optimization of the perching maneuver was conducted to minimize the fuel consumption with the magnitudes of thrusters as control variables. The problem was formulated as the dynamic optimization problem under constraints, and solved using the Gauss pseudo-spectral method. Gauss Pseudo Spectral method (GPM) is used to find the optimal solution. PID type controllers for the attitude and velocity control of the vehicle are suggested. The effectiveness of the controllers was validated by comparing its simulation results with the optimal trajectory.