Flight Trials of a Rotorcraft Unmanned Aerial Vehicle Landing Autonomously at Unprepared Sites

This paper describes the flight testing and evaluation of technologies for the autonomous landing of a Yamaha RMAX helicopter at non-cooperative sites without the aid of GPS. The Yamaha RMAX used for these flight trials has been modified to include stereo cameras, a scanning laser, and an avionics payload. Machine vision stereo range mapping is used to generate an accurate terrain representation, and a safe landing area determination algorithm is used to select the safest landing point within the terrain. A machine vision self-localization system is used to measure the helicopter position during the descent and landing when GPS is unavailable. The software and hardware architecture of the flight system is presented and each system component is described. Results and lessons learned from the flight evaluation and optimization of the individual components are reported as well as the overall system performance with respect to a set of objective metrics for the autonomous landing flight trails.