On-going UAV R&D at JAXA’s Aviation Program Group- Second Report with Emphasis on LTA Flight Control-

R&D on unmanned aerial vehicle (UAV) systems for the disaster monitoring has been conducted at JAXA since 2005. The Lighter than Air (LTA) type UAV is expected to be the essential part of such disaster monitoring UAV system. This paper reports the development and the flight test of LTA type UAV with much emphasis on its flight control and guidance system. In the course of conceptual design, an experimental vehicle or an LTA flying test bed was manufactured to prove key technologies. The test bed was a 14.0 m long unmanned non-rigid airship. It is controlled by commands from an R/C (radio control) transmitter (R/C mode) or the control signal from the onboard flight control computer FCC (autonomous mode). The FCC computes commands to effectors based primarily on attitude and position data from an onboard GPS/INS navigation system and airspeed data from a three-axis onboard ultrasonic anemometer. The onboard control system is developed basically similar to that in the 60m class unmanned airship that JAXA developed for the Stratospheric Platforms project., speed control, altitude control, and guidance in the horizontal plane are included. In addition to it, the hovering mode control that enables station keeping flight, automatic takeoff and landing is introduced. 3 flight tests were conducted in 2007 and 2008. The flight and guidance control worked well for the most part as: 1) Flight control functionalities of speed hold, altitude hold, and heading hold were verified; 2) Flight control and guidance functionality to trace way points was verified; 3) The capability of automatic landing as well as autonomous hovering was demonstrated