A Generalized Predictive Control-Based Path Following Method for Parafoil Systems in Wind Environments

Parafoil systems represent flexible wing vehicles. In case a vehicle is flying at low altitude, it is well known that the vehicle is more susceptible to winds. Also, due to the nonlinear, large inertial existing within the system, traditional control methods, such as traditional proportional-integral-derivative (PID), cannot guarantee the quality of path following. Therefore, we here apply generalized predictive control (GPC)-based method for parafoil systems to follow the designed path for a better control effect. To achieve this, we first propose a novel modeling method based on computational fluid dynamics to build a dynamic model of the parafoil system in windy environments. Afterward, a guidance law is designed according to a hybrid approach that combines the cross track error and the line of sight. In addition, the path following controller is established by using GPC. Finally, we generate and interpret numerical results to demonstrate the feasibility of the horizontal path following method in windy environments by utilizing the semi-physical simulation platform. The achieved results show that the GPC controller achieves high precision path following. More precisely, it possesses a better anti-wind ability and tracking accuracy and, therefore, the method outperforms PID controller.