Accurate Modeling and Homing Control for Parafoil Delivery System Based on Wind Disturbance Rejection

Abstract

Parafoil delivery systems play an irreplaceable role in the area of the airdrop supply and aircraft recovery. Their main function is to transport the payload to the target position. The system applies a large flexible parafoil to provide the lift force and control the flight direction. The parafoil is strongly nonlinear and vulnerable to the wind disturbance. To solve this problem, in this study, we explore a novel flexible modeling method and a homing control methodology for the parafoil. First, an 8-degree-of-freedom dynamic model is built. By clarifying the functions of the different aerodynamic coefficients, the model can maximally simulate the flight states of the system. Then, a trajectory planning method based on a Gaussian pseudospectral method is presented to calculate the optimal reference trajectory by considering the influence of the constant wind. Next, the wind disturbance, such as constant wind and gusts, is compensated by an improved active disturbance rejection controller (ADRC) in the trajectory tracking. Finally, compared with the traditional PID and ADRC, the results of the flight experiment illustrate the correctness and feasibility of the proposed modeling and homing control methodology.