Abstract:

In practical applications, autonomous quadrotors are still facing significant challenges, such as the detection and avoidance of very small and even dynamic obstacles (e.g., tree branches, power lines). In our research, we propose a compact, integrated, and fully autonomous quadrotor system, which can fly safely in clutter environment while avoiding dynamic small obstacles. Our quadrotor platform is equipped with a forward-looking three‐dimensional (3D) light detection and ranging (lidar) sensor and an inertial measurement unit (IMU) to perceive the environment and an onboard embedded computer to perform all the estimation, control, and planning tasks. The computer estimates the current pose of the UAV, maintains a local map (time-accumulated point clouds KD-Trees) and computes a safe trajectory using kinodynamic A* search to the goal point. The whole perception and planning system can run onboard at 50Hz with careful optimization. Indoor and outdoor experiments have proved that the system can avoid dynamic small obstacles (down to 20mm diameter bar) while flying at 2m/s in clutter environments.