Adaptive fractional‐order nonsingular fast terminal sliding mode formation control of multiple quadrotor UAVs‐based distributed estimator

Abstract

This paper mainly solves two major problems that are unavoidable in leader–follower formation process of quadrotor UAV group: the existence of external uncertainty disturbance and communication limited between quadrotor unmanned aerial vehicle (UAV) group. To solve the problem that only one of the followers in the leader–follower formation can obtain the leader's information, an improved distributed estimator is proposed in this paper, which can accurately estimate the leader's information for each follower. In addition, in order to eliminate the influence of uncertain external disturbance on the performance of quadrotor UAV, an adaptive estimation law is designed based only on velocity and position variables. For the attitude and position subsystem of the quadrotor UAV, a sliding surface with fractional‐order term is designed. Which makes the quadrotor UAV tracking error system obtain good robustness at the stage of reaching the sliding surface and fast convergence and accurate tracking performance in the sliding stage. Based on Lyapunov stability theory, the convergence results are analyzed strictly. The results show that the algorithm can make the position distance between leader and followers converge to the desired offset. Simulation results verify the effectiveness and superiority of the control algorithm.

Surrogate Optimal Fractional Control for Constrained Operational Service of UAV Systems

“…In order to mitigate disturbance, a FOC-extended state observer of a Tri-copter UAV was developed in [27]. Furthermore, an adaptive FOCsliding mode formation control of a multiple quadrotor UAV-based distributed estimator was developed in [28]. The authors in [29] proposed a robust formation tracking problem for a heterogeneous multi-robot system with FOC, consisting of UAVs and unmanned surface vehicles (USVs), to handle multiple disturbances.…”

Event‐triggered sampled‐data synchronization of complex networks with uncertain inner coupling and time‐varying delays

“…Sampled-data control (SDC) has important applications in digital technology, aerospace, and signal transmission [18]. The term SDC refers to the process in which the continuous-time input signal is sampled and quantized by a digital computer to generate a discrete-time input signal, which eventually reverts to a continuous-time input signal through the action of a zero-order holder (ZOH) [19][20][21]. In the sampling control system, it has been observed that as the sampling interval increases, there is a corresponding reduction in communication channel occupancy, a decrease in controller drive load, and a decrease in signal transmission [22,23].…”