국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Flight Test Evaluation of the ILS on the Mega-Float Airport using the MuPAL-ε Research Helicopter
저자	Yoshinori Okuno, Naoki Matayoshi, Koki Hozumi, Kohei Funabiki, Hirokazu Ishii, Hisashi Yokoyama
Keyword	Helicopter; ILS; Flight Test
URL	http://send.nal.go.jp/send/jpn/dlpdf.php3/naltr0001429.pdf?id=NALTR0001429
보고서번호	NAL-TR-1429
발행년도	2001. 7
출처	NAL (National Aerospace Laboratory of Japan)
ABSTRACT	Flight test evaluation of an Instrument Landing System (ILS) sited on the Mega-Float, an experimental floating airport, was conducted using the National Aerospace Laboratory of Japan's MuPAL-e research helicopter. As a possible solution to the need for new airports, the Technological Research Association of Mega-Float has been developing floating airport technologies and has constructed the world's largest floating marine structure offshore of Yokosuka, in Tokyo Bay, as an experimental facility. This so-called Mega-Float has a runway measuring 1,000 meters long, 60 meters wide (the entire facility is up to 120 meters wide), and 3 meters thick. Since the Mega-Float is constructed mainly from steel, there is the possibility of electromagnetic influence affecting radio waves emitted by equipment such as ILS transmitters, radio altimeter, and Doppler velocimeter. The ILS glide slope radio signal, which is formed by both direct radio waves from an antenna and ground reflection waves, is thought to be particularly susceptible to such influences. To investigate possible radio anomalies, MuPAL-e conducted ILS approaches to compare received ILS signals with accurate position data obtained from an onboard hybrid DGPS/INS navigation system. ILS sweep maneuvers that exploit the unique flight capabilities of a helicopter, such as hover, vertical climb and sideways flight, were also carried out around the ILS approach path. Some characteristic ILS signal errors were observed, such as a periodic fluctuation of the glide slope signal and an asymmetric variation of the localizer signal. Numerical analysis conducted by the Electronic Navigation Research Institute revealed that these radio anomalies were mainly due to the diffraction of radio waves by the edges of the Mega-Float structure, the control tower located beside its runway, and "dolphin" structures (piles to which the Mega-Float is moored in the open water). The presented ILS evaluation method was thus demonstrated to be effective for directly measuring the spatial distributions of ILS signal errors and clarifying their causes.