Coordinated Path Following of UAVs using Event-Triggered Communication over Networks with Digraph Topologies

TL;DR

This work tackles coordinated path following for multiple UAVs under limited communications by introducing a decentralized event-triggered communication scheme on digraph topologies. Each UAV maintains a coordination state $\gamma_i(t)$ and a trajectory reference $p_{d,i}(\gamma_i(t))$, with a Lyapunov-based ETC controller ensuring exponential convergence of coordination errors while guaranteeing Zeno-exclusion. The contributions include a concrete ETC-based control law, neighbor-estimation mechanisms, and rigorous stability analysis, validated by simulations on quadrotors showing reduced communication and robust synchronization under disturbances. The approach enables scalable, energy-efficient UAV coordination in networks with time-varying connectivity and constrained bandwidth.

Abstract

This article presents a novel time-coordination algorithm based on event-triggered communication to ensure multiple UAVs progress along their desired paths in coordination with one another. In the proposed algorithm, a UAV transmits its progression information to its neighbor UAVs only when a decentralized trigger condition is satisfied. Consequently, it significantly reduces the volume of inter-vehicle communications required to achieve the goal compared with the existing algorithms based on continuous communication. With such intermittent communications, it is shown that a decentralized coordination controller guarantees exponential convergence of the coordination error to a neighborhood of zero. Furthermore, a lower bound on the difference between two consecutive event-triggered times is provided showing that the Zeno behavior is excluded with the proposed algorithm. Lastly, simulation results validate the efficacy of the proposed algorithm.

Figures (6)

• Figure 1: Time-coordinated path-following of five quadrotors. The starting points of the desired trajectories, blue dots, are on $y=0\,m$. The final points, red dots, are on $y=150\,m$.
• Figure 2: Topology of the underlying communication network.
• Figure 3: Convergence of the coordination error $\gamma_i(t)-\gamma_j(t)$$(i<j)$ to a neighborhood of zero.
• Figure 4: Convergence of $\dot{\gamma}_i(t)$ to a neighborhood of $\dot{\gamma}_d(t)$.
• Figure 5: Path-following errors.

Theorems & Definitions (10)

• Remark 1
• Remark 2
• Remark 3
• Remark 4
• Remark 5
• Lemma 1
• proof
• Theorem 1
• proof
• Remark 6