4-DOF longitudinal dynamic simulation of powered-parafoil

With the consideration of relative motion between payload and canopy, longitudinal dynamic of parafoil was simulated. Canopy and suspension line were regarded as a 3-DOF rigid body. Adding another degree of freedom of swing payload, a 4-DOF longitudinal dynamic model was proposed. Dynamic response was solved after step increasing of throttle which led to increasing of climbing angle. The main reason of canopy collapse that happens just after throttle up is the rapid changes of angle of attack which can be over the stall angle. Control envelope was calculated that is composed of throttle value and corresponding growing rate of throttle. Little change of power up has no limit on increasing rate, but large change does, and the limit increases with the increasing throttle value. In addition, mechanical energy change of payload before and after landing was calculated. Rapid power up control was proposed as a new flare landing method for powered-parafoil. The results of mechanical energy analysis method show that this new flare control can decrease mechanical energy at the moment of landing that means weaker shock to front power system.