Autonomous navigation in unknown environments with obstacles remains challenging for micro aerial vehicles (MAVs) due to their limited onboard computing and sensing resources. Although various collision avoidance methods have been developed, it is still possible for drones to collide with unobserved obstacles due to unpredictable disturbances, sensor limitations, and control uncertainty. Instead of completely avoiding collisions, this article proposes Air Bumper, a collision detection and reaction framework, for fully autonomous flight in 3D environments to improve the safety of drones. Our framework only utilizes the onboard inertial measurement unit (IMU) to detect and estimate collisions. We further design a collision recovery control for rapid recovery and collision-aware mapping to integrate collision information into general LiDAR-based sensing and planning frameworks. Our simulation and experimental results show that the quadrotor can rapidly detect, estimate, and recover from collisions with obstacles in 3D space and continue the flight smoothly with the help of the collision-aware map.

翻译：在未知环境中自主导航并规避障碍物对微型飞行器（MAV）而言仍具挑战性，这主要受限于其机载计算与传感资源。尽管已开发出多种避障方法，但由于不可预测的干扰、传感器局限以及控制不确定性，无人机仍可能与非观测障碍物发生碰撞。本文并非主张完全避免碰撞，而是提出一种名为Air Bumper的碰撞检测与反应框架，用于实现3D环境下的全自主飞行，从而提升无人机的安全性。本框架仅利用机载惯性测量单元（IMU）来检测并估计碰撞。我们进一步设计了碰撞恢复控制以实现快速恢复，并构建了碰撞感知映射模块，将碰撞信息集成至通用的LiDAR传感与规划框架中。仿真与实验结果表明，四旋翼飞行器能够快速检测、估计并恢复与3D空间中障碍物的碰撞，并借助碰撞感知地图平滑地继续飞行。