Abstract:

To address the problem of the collaborative motion control problem for air-ground heterogeneous unmanned system composed of multi-unmanned aerial vehicle （UAV） and multi-unmanned ground vehicle （UGV）, based on an event-triggered communication strategy, a fast fixed-time time-varying formation containment control algorithm with disturbances is proposed. Firstly, according to air-ground collaborative mission types, the system desired trajectory, multi-UAV, and multi-UGV are defined as three-dimensional （3-D） tracking navigator, 3-D formation leader, and two-dimensional （2-D） follower, respectively. Then, the system is divided into two subgroups based on the state variable dimensions of each individual, and a unified mathematical model that characterizes the different degrees of freedom is established in the state space for the whole system according to the subgroup variable dimensions. Next, a distributed fixed-time event-triggered observer is developed for the 3-D formation leader to observe the information of the 3-D tracking navigator and a fixed-time formation controller for them based on the observation information. Furthermore, a distributed fixed-time event-triggered convex hull observer is proposed for the 2-D follower to estimate the convex hulls spanned by the 3-D formation leader, and a fixed-time formation containment controller is designed for all 2-D follower. Theoretical analysis indicates that, compared to the upper bound of the estimated time in traditional fixed-time cooperative control algorithms, the fixed-time formation control algorithm proposed in this paper exhibits lower conservatism, with its upper bound being closer to the actual convergence time of the system formation. Finally, this claim is verified through comparative simulation experiments.

Key words: unmanned aerial vehicle(UAV)-unmanned ground vehicle(UGV) system, time-varying formation containment control, event-triggered communication, distributed collaborative observation, fixed-time stability convergence