This article investigates the problem of fixed-time formation tracking control for a heterogeneous multiagent system composed of unmanned aerial vehicles and unmanned ground vehicles in the presence of actuator faults, model uncertainties, and external disturbances. First, two fixed-time distributed observers are proposed, one of which is applied to detail-balanced directed graph and the other is applied to general directed graph. These two observers remove the requirements of global information and control signal of leader, as well as reduce communication flow. Second, a fixed-time disturbance observer is designed for each follower to estimate lumped uncertainties. Third, a Lyapunov-based formation controller is proposed to guarantee that the fixed-time synchronized formation is achieved for heterogeneous multiagent systems using estimation and backstepping technique. Furthermore, the obtained upper bound of convergence time only depends on the observer gains and controller parameters, which facilitates the adjustment of the settling time offline regardless of initial conditions under different formation requirements. Finally, the effectiveness of the proposed fixed-time protocol is verified using numerical simulations.

中文翻译：

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执行器故障和定向拓扑下异构多智能体系统的固定时间编队跟踪


本文研究了由无人机和无人地面车辆组成的异构多智能体系统在存在执行器故障、模型不确定性和外部干扰的情况下的固定时间编队跟踪控制问题。首先，提出了两种固定时间分布式观测器，其中一个应用于细节平衡有向图，另一个应用于一般有向图。这两个观察者消除了领导者对全局信息和控制信号的要求，并减少了通信流量。其次，为每个跟随器设计固定时间扰动观测器来估计集总不确定性。第三，提出了一种基于李雅普诺夫的编队控制器，利用估计和反步技术保证异构多智能体系统实现固定时间同步编队。此外，所获得的收敛时间上限仅取决于观测器增益和控制器参数，这有利于在不同地层要求下，无论初始条件如何，都可以离线调整稳定时间。最后，通过数值模拟验证了所提出的固定时间协议的有效性。