Resilience Assessment of Low-Altitude UAV Swarms Under Coupled Multi-Source Safety Constraints

Low-altitude UAV swarms in urban airspace simultaneously face conflict, environmental, communication, and energy constraints, which are tightly coupled and may trigger cascading failures through nonlinear amplification. Most existing studies focus on single-constraint risk and rarely account for coupling-driven cascading effects on swarm resilience. This paper proposes a resilience assessment method for low-altitude UAV swarms under coupled multi-source safety constraints. Four core constraints are quantified and aggregated through cross-coupling terms into a composite safety-constraint index; a cascading-failure model embeds the coupling amplification into both triggering and propagation; and a comprehensive resilience index is constructed from structural and functional dimensions via percolation theory. A case study on an urban logistics swarm shows that four-constraint coupling drops the comprehensive resilience index by 43.6% relative to normal operation, with coupling amplification up to$15.9\%$; ignoring coupling systematically underestimates risk, and the environmental constraint exerts the strongest independent influence among the four.