Modeling and Simulation of sUAS Impact Characteristics Following In-Flight Failures

The injury potential to a human from a descending small Unmanned Aerial System (sUAS) following an in-flight failure has a large impact on how the FAA chooses to regulate sUAS flight over people. The impact characteristics of any sUAS post in-flight failure must be known before operating over people to determine how much impact energy the vehicle may introduce during the collision. This paper focuses on Modeling and Simulation of sUAS post in-flight failure to estimate its impact characteristics. Quadrotor models of three commercial UAVs are developed. Their post failure trajectories are simulated and validated from flight tests conducted at University of Alabama in Huntsville. Monte Carlo Simulation are also performed to estimate the worst-case impact for each vehicle and identify the effects of UAV flight altitude, velocity at the instant of failure, vehicle attitude, failure types and wind conditions on the UAV impact energy, impact orientation and horizontal displacement. Results from modeling agree very closely with flight tests. Modeling and Simulation results highlight the maximum velocities reached, impact angles, tumbling behavior of UAVs, and the effect of size, shape and mass of the UAV.