Flapping-Wing UAV Autonomous Obstacle Avoidance

Bio-inspired monocular perception, image stabilization, reinforcement learning, and real-flight validation for a bird-like flapping-wing micro UAV.

This project studied autonomous obstacle avoidance for a bird-like flapping-wing micro aerial vehicle. Unlike multirotor UAVs, flapping-wing aircraft have severe constraints in size, payload, onboard computation, and image stability, while still needing fast perception, planning, and control during forward flight.

The platform had a total takeoff weight of about 250 g, a payload budget of about 20 g, and a flight speed of around 10 m/s. These constraints made common stereo or depth-camera solutions unsuitable, so the system used a lightweight monocular camera and a bio-inspired perception pipeline.

Key technical components:

  • Bio-inspired monocular obstacle perception based on the LGMD mechanism, inspired by insect compound-eye neural responses to looming objects.
  • IMU-assisted image stabilization to reduce flapping-induced pitch oscillation and improve monocular perception reliability.
  • AirSim-based simulation training for constant-altitude obstacle avoidance, where the UAV avoided trees through roll commands while flying toward a target.
  • Deep reinforcement learning policy training and deployment to real-world flight tests.
  • Real-flight validation on the “Xinge” flapping-wing UAV, with 10 minutes of flight time and 14 autonomous-mode switches, all completing obstacle avoidance successfully.
Bird-like flapping-wing UAV platform used for autonomous obstacle avoidance experiments.
Bio-inspired LGMD perception: looming obstacles generate progressively stronger visual responses before collision.
IMU-assisted monocular image stabilization reduced the effect of flapping-induced pitch oscillation on visual perception.
AirSim simulation environment for reinforcement-learning-based obstacle avoidance training.
Real-world autonomous obstacle avoidance flight test at Northwestern Polytechnical University. 2023.03.31
Flight test video: autonomous obstacle avoidance with a bird-like flapping-wing UAV.