Reactive inflight obstacle avoidance via radar feedback

Avoidance of unmapped obstacles is critical to autonomous flight in forested areas and urban canyons. The small vehicles capable of navigating in these spaces necessarily cannot carry the heavy and sophisticated sensor packages carried on large aircraft. We propose simple reactive feedback laws that enable obstacle avoidance for a hover-capable unmanned aerial vehicle (UAV) using a crude low resolution, small field of view radar sensor. The basic component in these laws is the reduction in the velocity component in the direction of the obstacle. We illustrate the performance of these feedback laws on a point mass double integrator model with velocity and acceleration limits. Simulation results in both 2-D and 3-D settings are presented.