Dynamic modeling, control aspects and model predictive control of a parafoil and payload system

Control issues are investigated for a parafoil and payload system with left and right parafoil brakes used as the control mechanism. It is shown through dynamic modeling and simulation that parafoil and payload systems can exhibit two basic modes of lateral control, namely, roll and skid steering. Using a small parafoil and payload aircraft, glide rates and turn performance were measured and compared against a 9 DOF simulation model. This work shows that to properly capture control response of parafoil and payload aircraft, tilt of the parafoil canopy must be accounted for along with left and right parafoil brake deflection. Alternative methods of controlling a parafoil and payload by tilting the canopy for lateral control and changing rigging angle for longitudinal control are evaluated. A model predictive control strategy is developed for an autonomous parafoil and payload system. It is demonstrated in flight tests that a model predictive control strategy is a natural and effective method of achieving trajectory tracking in a parafoil and payload system.