Research on dynamics behaviours of small UAV parachute recovery system

The constraint between a parachute and a small UAV is quite complicated, and it is difficult to accurately establish the dynamics model of the small UAV parachute recovery system. In order to solve problems, a small UAV parachute recovery system is considered as a multibody system, including a parachute and a small UAV, and the connection between the parachute and the small UAV is assumed as a fixed point. The aerodynamic forces and moments of the parachute and the small UAV are established respectively, and they are introduced into the centre of mass of the parachute recovery system via virtual work. Then, based on Lagrangian equation, a six-degree-of-freedom dynamics model of the system is established. Finally, the accuracy of this model is verified. The influences of the parachute reference diameter and the system initial forward velocity on the dynamics of the recovery system are also studied in this paper.