Formation Flight Control of Networked-Delayed Quadrotors for Cooperative Slung Load Transportation

A formation control with fixed-time stability under network delay is investigated in this paper for a team of quadcopters cooperatively carrying a slung payload under a leader-follower paradigm. The vehicles’ dynamics are subject to nonlinearities, matched internal/external perturbation, and load disturbances. First, an Artstein’s reducing transformation is skillfully utilized to transform the input time-delayed double integrator error system into a delay-free system. Then, a novel Distributed Fixed-Time Homogeneous Sliding Mode Control Protocol (DFHSMC) is proposed for the multi-quadrotor system. Moreover, the control scheme comprises a disturbance observer to compensate for the lumped disturbances affecting the position dynamics. Thus, achieving the transportation task with a minimal swing. Overall, the synthesized controller can stabilize the delayed formation tracking errors at the origin in fixed-time uniformly to the values of the Initial Conditions (ICs). Besides, an explicit expression for the upper-bound on the settling-time is given. Finally, real experiments are carried out to corroborate the findings of this research work.