Parachute dynamics and perturbation analysis of precision airdrop system

To analyze the parachute dynamics and stability characteristics of precision airdrop system, the fluid–structure interaction (FSI) dynamics coupling with the flight trajectory of a parachute–payload system is comprehensively predicted by numerical methods. The inflation behavior of a disk-gap-band parachute is specifically investigated using the arbitrary Lagrangian–Euler (ALE) penalty coupling method. With the available aerodynamic data obtained from the FSI simulation, a nine-degree-of-freedom (9DOF) dynamic model of a parachute–payload system is built and solved to simulate the descent trajectory of the multi-body dynamic system. Finally, a linear five-degree-of-freedom (5DOF) dynamic model is developed, the perturbation characteristics and the motion laws of the parachute and payload under a wind gust are analyzed by the linearization method and verified by a comparison with flight test data. The results of airdrop test demonstrate that our method can be further applied to the guidance and control of precision airdrop systems.