Optimization of deep stall landing trajectory for morphing aided UAV

In order to recover small unmanned aerial vehicles (UAVs) at a confined area, deep stall landing is investigated for UAV aided by morphing wing. Inspired by perching maneuver of birds, morphing wing is adopted to gain extra controllability during deep stall landing. Constraints like terminal velocity, sink rate, terminal attitude, down range of approach, input saturation, etc are considered. Then, deep-stall landing problem of small UAV aided by morphing wing in longitudinal plane has been formulated as an optimal control problem. The optimal trajectory and nominal reference control is solved numerically based on Gauss pseudo spectral method. Numerical results verify the effectiveness of proposed optimization method, and characteristics and mechanisms of optimized deep-stall landing trajectory for morphing aided UAV are discussed under various flight conditions and limits.