AN “OFF THE SHELF” AVIONIC SYSTEM FOR ROTARY WING UAV RAPID PROTOTYPING

This paper presents the results, achieved at the Aerospace Engineering Department Laboratories of the University of Bologna - Italy (UNIBO), concerning the development of a “commercial off the shelf” (COTS) avionics system for rapid prototyping of small scale Rotary wing UAVs (RUAVs). The RUAV avionics package was developed as an integrated modular system using commercial and cost effective technologies. The avionics package is comprised of sensors, computer and data link hardware as well as software to control the vehicle. The CompactRio (cRIO) system from National Instruments was chosen as flight computer due to its reliability and reconfigurable architecture, to enable fast and easy integration of different input/output hardware and sensors. The Hirobo 60 helicopter mechanics was used as flying platform and modified to accommodate the avionics hardware. A more powerful engine, longer fiberglass blades, longer tail boom and tail blades were also mounted in order to increase the helicopter payload carrying capabilities. The avionic system was fast and easily programmable, resulting in a sudden speed-up of onboard hardware/software development and integration. The setup of this electronic package allowed recording of helicopter responses to pilot commands and provided deep insight into the small scale rotorcraft dynamics, facilitating the development helicopter models and control systems in the UNIBO Hardware In the Loop (HIL) simulator. A classical PI attitude controller was developed to test the avionics package control capabilities. First flight tests were performed in hovering conditions. Comparison between HIL simulation and experimental results showed good agreement.