A Resilient Forward-Looking Terrain Avoidance Warning Method for Helicopters

To reduce nuisance alarms caused by a fixed forward-looking boundary, this paper proposes a resilient forward-looking terrain avoidance method. The method constructed the resilient and adjustable forward-looking boundary model by using roll angle and navigation error, which makes the terrain data employed by the forward-looking alert closer to the terrain data overflown by the anticipated flight trajectory, reduces the nuisance alarm, and improves the reliability of the alert. Using real digital elevation maps and simulated flight testing, the proposed method was observed to provide alerting that is superior to the traditional forward-looking terrain avoidance technique.