A simplified virtual obstacle avoidance approach for aircraft altitude bounded flight maneuvers

Avoiding collision with obstacles and terrain has always been a critical issue for aircraft during low altitude flight landing and approach maneuvers, especially in airports located in mountainous areas. In low altitude flight, it is desirable to find a safe trajectory that is compatible with the aircraft capabilities and at the same time optimizes flight efficiencies. Safety is a fundamental concern when in terrain following (TF) and/or terrain avoidance (TA) flight modes, and aircraft design for these types of missions emphasizes the inclusion of terrain and obstacle avoidance flight (TOAF) capabilities.