ImpedanceDiffusion: Diffusion-Based Global Path Planning for UAV Swarm Navigation with Generative Impedance Control

Safe swarm navigation in cluttered indoor environment requires long-horizon planning, reactive obstacle avoidance, and adaptive compliance. We propose ImpedanceDiffusion, a hierarchical framework that leverages imageconditioned diffusion-based global path planning with Artificial Potential Field (APF) tracking and semantic-aware variable impedance control for aerial drone swarms. The diffusion model generates geometric global trajectories directly from RGB images without requiring explicit map construction. These trajectories are tracked by an APF-based reactive layer, while a VLM-RAG module performs semantic obstacle classification with ${9 0 \%}$ retrieval accuracy to adapt impedance parameters for mixed obstacle environments during execution. Two diffusion planners are evaluated: (i) a topview long-horizon planner using single-pass inference and (ii) a first-person-view (FPV) short-horizon planner deployed via a two-stage inference pipeline on top view. Both planners achieve a ${1 0 0 \%}$ trajectory generation rate across twenty static and dynamic experimental configurations and are validated via zero-shot sim-to-real deployment on Crazyflie 2.1 drones through the hierarchical APF-impedance control stack. The top-view planner produces smoother trajectories that yield conservative tracking speeds of $1. 0 - 1. 2 \mathrm{m} / \mathrm{s}$ near hard obstacles and ${0. 6}-{1. 0} \mathrm{m} / \mathrm{s}$ near soft obstacles. In contrast, the FPV planner generates trajectories with greater local clearance and typically higher speeds, reaching ${1. 4 - 2. 0} \mathrm{m} / \mathrm{s}$ near hard obstacles and up to $1.6 \mathrm{m} / \mathrm{s}$ near soft obstacles. Across 20 experimental configurations (100 total runs), the framework achieved a ${9 2 \%}$ success rate while maintaining stable impedance-based formation control with bounded oscillations and no in-flight collisions, demonstrating reliable and adaptive swarm navigation in cluttered indoor environments. Video of ImpedanceDiffusion: https://youtu.be/J-Ec2arIJVwGitHub of ImpedanceDiffusion: https://github.com/FaryalBatool/ImpedanceDiffusion.