Omni-Directional Aerial Transportation System: Modeling, Control, and Experimental Validation

Aerial transportation systems have demonstrated unique application value in various fields, particularly in logistics transportation, and have garnered significant attention recently. Most of the existing researches on cable-suspended transportation system regard the payload as a point mass, neglecting the attitude of the payload. To achieve the attitude control of nonpoint mass payload during transportation, that can significantly expand the application scope, this article develops the omni-directional aerial transportation system, where a fully actuated UAV is utilized instead of the underactuated UAV, and a bar-shaped payload is slunged by two cables. However, compared with the single-cable suspension system, this system manifests more complex dynamic coupling and nonlinearity. Specifically, the UAV's attitude subsystem is coupled with the swing of payload. To deal with these problems, an antiswing control approach is presented, where an enhanced-coupling signal is constructed to improve the capability of payload swing elimination. The asymptotic convergence of the equilibrium point is strictly proved by Lyapunov techniques and LaSalle's invariance theorem. Furthermore, two groups of hardware experiments are conducted to validate the effectiveness of the proposed control method. To the best of our knowledge, the omni-directional aerial transportation system and control solution are developed to achieve the attitude control of payload during transportation with single UAV for the first time in this article.