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形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2016-10-28, 資料番号: PA1720006000

Fukushima Dai-ichi nuclear power plant received a severe damage due to huge tsunami waves caused by the Great East Japan Earthquake in 2011. This tragedy requires radiation monitoring around the plant using unmanned systems, this paper therefore addresses the flight controller design for an unmanned airplane which is developed for the radiation monitoring. The flight controller has a conventional structure, i.e. Stability/Control Augmentation System (S/CAS) and guidance loops using PID controllers. The controller gains are determined by minimizing appropriately defined cost functions for several models; that is, the worst control performance among multiple models is minimized to obtain robust flight controller gains (so-called “multiple model approach”). Control performance of our flight controller was evaluated through flight tests and preliminary demonstration flights were conducted near the plant.

In 2011, Fukushima Dai-ichi nuclear power plant received a severe damage from the Great East Japan Earthquake, and spread massive radioactive contaminants. Due to this tragedy, the necessity of unmanned radiation monitoring system has been increasing in Japan. Therefore, Japan Aerospace Exploration Agency (JAXA) and Japan Atomic Energy Agency (JAEA) have been jointly developing Unmanned Airplane for Radiation Monitoring System, in short UARMS, as one of such systems. The basic flight controller of UARMS was designed and the usefulness of UARMS has already been well illustrated by demonstration flight in Fukushima; however path-tracking controller has been required for precise monitoring because radiation monitoring is planned to be conducted not only in town areas but also in mountain areas. To this end, the path-tracking controller is designed as a preview controller with its gains being optimized off-line by using multiple model approach for robust control performance. Demonstration flight was conducted in Fukushima to confirm the integrity of the designed preview path-tracking controller.

The performance of the Direct Lift Control system of NAL’s new in-flight simulator, “MuPAL-α ”, was evaluated by wind tunnel and flight tests. As a result, it was proved that: 1) The vertical acceleration generated by the DLC system satisfies the design requirements; 2) The maximum rolling and yawing moments created by asymmetric deflection of the DLC flaps are easily cancelled by aileron deflection, so malfunction of the DLC system has little effect on the safety of the aircraft.