Onboard trajectory generation for compound UAV during the unpowered approach phase

To perform autonomous unpowered approach to designated landing interface, a three-dimensional trajectory generation method for compound UAV is presented. A reference profile by piecing together three flight segments is adopted in the trajectory generation scheme. By predict-correct method, the algorithm adjusts three parameters´ values of the trajectory and propagates the trajectory to match the landing interface status. Unlike the usually used optimization method, the method is able to generate reference profiles quickly, which indicates its ability for onboard calculation. Numerical results from different scenarios are presented in order to validate the effectiveness of the method.