Dynamic stability analysis of a single-point hanging container

To study the dynamic stability of a single-point hanging container, the divergent motion of the hanging container was captured by a wind tunnel test, and the motion equation of the single-point hanging system was decoupled for dynamics analysis. It was found that the reason for the divergent motion of the container was that the lateral aerodynamic force had a motivating effect on the swing motion. The stability criterion showed that the necessary condition for the stability of the single-point hanging system was the damping action of the yawing moment and lateral force of the hanging body on its yawing motion, but an excessive yawing recovery force may reduce the dynamic stability of the hanging system. Keeping the lateral damping force and yawing recovery moment appropriate, reducing the resistance, and increasing the mass and moment of inertia of the hanging body were beneficial to the stability of the hanging system. In the process of hanging flight, if the hanging system becomes unstable, the helicopter can be controlled by decelerating properly, and the sling length can be reduced to increase the flight speed of the stable forward flight of the helicopter with an external hanging body. Besides, there is an optimal sling length to ensure the optimal stability of the single-point hanging system at cruising speed.