  It is ubiquitously accepted that during the autonomous navigation of the
quadrotors, one of the most widely adopted unmanned aerial vehicles (UAVs),
safety always has the highest priority. However, it is observed that the ego
airflow disturbance can be a significant adverse factor during flights, causing
potential safety issues, especially in narrow and confined indoor environments.
Therefore, we propose a novel method to estimate and adapt indoor ego airflow
disturbance of quadrotors, meanwhile applying it to trajectory planning.
Firstly, the hover experiments for different quadrotors are conducted against
the proximity effects. Then with the collected acceleration variance, the
disturbances are modeled for the quadrotors according to the proposed
formulation. The disturbance model is also verified under hover conditions in
different reconstructed complex environments. Furthermore, the approximation of
Hamilton-Jacobi reachability analysis is performed according to the estimated
disturbances to facilitate the safe trajectory planning, which consists of
kinodynamic path search as well as B-spline trajectory optimization. The whole
planning framework is validated on multiple quadrotor platforms in different
indoor environments.
