Fault-Tolerant Control for Multirotor Aerial Transportation Systems With Blade Damage

Aerial transportation systems are important ways for cargo delivery, especially in forest fire-fighting, postdisaster rescue, etc. While the harsh working environments may lead to multirotor failure, such as blade damage. Due to the inherent dynamic coupling existing between the payload and the multirotor, the blade damage will not only affect the dynamics of the multirotor and cause positioning failure but also aggravate the payload sway motion. In order to ensure the positioning accuracy and reduce payload oscillations, a fault-tolerant control scheme for the aerial transportation system is in urgent need. To this end, a finite-time disturbance observer-based nonlinear hierarchical control scheme is designed for the aerial transportation system to handle the lumped disturbance caused by blade damage. Specifically, the following two control objectives are achieved: 1) both the positioning of the multirotor and 2) the swing suppression of the payload with blade damage condition. Lyapunov techniques and LaSalle's invariance theorem are utilized to prove the convergence of the equilibrium point. Finally, simulation and experiment tests are conducted to verify the excellent performance of the proposed control scheme with different damage degrees of blades. As far as we know, this article proposes the first fault-tolerant controller for multirotor aerial transportation systems to realize simultaneous multirotor positioning and payload swing suppression even with blade damage.