#Aerial Robotics #LiDAR Inertial Odometry #State Estimation #Robot Safety #Drone #PX4

A real forest flight of our quadrotor, mapped by AGIptive-LIOM: from take-off through the forest and back to the take-off point, then the whole loop from above (offline replay, 10× speed, points coloured by height).

A quadrotor that flies on LiDAR-inertial odometry closes its control loop on the estimate, so a divergence that nobody notices can cost the vehicle. Many of the failures we met came from the sensors rather than the scene: clock steps, a blocked view, starting while moving, an IMU that clips at impacts. AGIptive-LIOM is a flight-safe, failure-aware LiDAR-inertial odometry for quadrotors: it guards against these faults, knows when its estimate is degraded, and tells the flight controller.

Highlights

  • Guards against real sensor faults. A timing layer tells a clock step from a data dropout using the other sensor's timestamps and repairs the step; further guards handle a blocked view, a moving start and merged scans.
  • Knows when it is degraded. An onboard health monitor that needs no ground truth reports OK, DEGRADED or FAILED with every scan, including a drift indicator for directions the LiDAR cannot see.
  • Tells the flight controller. The monitor sets the quality of the vision message to PX4, so PX4's own filter stops fusing a failed estimate. In simulated closed-loop flights this kept PX4's filter on the truth while the odometry failed.
  • Judged by how it fails. Eight methods on identical public recordings, fault injection and closed-loop simulated flights, with failures counted by cause. It is not the most accurate method, and real flights in the loop are still to come.
Position error over 70 seconds on a log scale, on a hopping robot whose IMU clips at every landing. FAST-LIO2 diverges to thousands of metres, Point-LIO drifts to metres, AGIptive-LIOM and RESPLE2 stay at centimetres.

A hopping robot whose internal IMU clips at every landing (public HOPPER data, one run per method). FAST-LIO2 diverges and Point-LIO drifts; AGIptive-LIOM and RESPLE2 stay at a few centimetres.

Code will be released once the paper is submitted.