Low Altitude Flight Collision Avoidance with Using Digital Terrain Map Information

• Main Authors: Yeu-Chen Liou, 劉宇誠
• Other Authors: Ching-Shun Ho
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/33800365602214153605

碩士 === 國立成功大學 === 航空太空工程學系 === 87 === An avionic flight-warning system is one of the key factors in avionics safety. The traditional systems are relied on the position reports from either incoming flight or the radar detection. These are basically in the field of point-by-point computation. This study adopts a volume search approach with the aids from the digital terrain map (DTM). Due to a lot of civil avionic accidents occurred in mountain clash, the research scenario is set to be low attitude, low visibility, and rapid change in the circumstance. The main goal of this study is to design a flight warning system with 3D capability in which the positions of the studied vehicle are derived from GPS with the terrain information from the aerial photographs. The designed system has the process procedures including data extraction, distance computation, and graphic display. The whole process time has to be within an acceptable time interval. The designed system is tested by a simulated helicopter flight with using a true DTM data. Three data extraction approaches are adopted: full, static, and dynamic extractions. The dynamic extraction provides the best result with the total computation time under 0.09 seconds with 2-meter resolution. When the resolution requirement rise up to 8-meter, the computation time is within 0.006 seconds. Three flight conditions are also considered. The air speed is the main factor in the consideration. There are three levels: 0~80, 80~160, and > 160 km/hr. The designed response time is set to be 5 seconds. The system provides different resolutions of DTM according to various velocities.