Fig. 4

Determination of the threat cost. rectangular threat zones (expanded by a safety buffer \({d}_{i}\)) are defined around buildings. For the waypoint set \({d}_{k}\), if a path point enters zone \({d}_{k}\in \left({X}_{i}-{d}_{i},{X}_{i+1}-{d}_{i}\right)\) (extended boundary), penalty R applies; if within \({d}_{k}\in \left({X}_{i},{X}_{i+1}\right)\) (obstacle space), penalty \(\infty\) activates.