Volcanic Ash Region Path Planning Based on Improved A-Star Algorithm

Table 1

Abbreviation table.

Symbol	Description
F(n)	The total cost from the global starting point to the global target point
	The cost of the shortest path from the global starting point to the current position
h(n)	The estimated cost of the shortest path from the current position to the global target point
PB	Position of volcanic ash condensation nuclei
VB	The speed of volcanic ash
RB	Radius of volcanic ash clouds
B	Volcanic ash area
VA	The speed of an airplane
N	The exploration node in the running space of the algorithm
ORCA	Optimal reciprocal collision avoidance
P(n)	The possibility of node x
Wi	The node to be explored in the next step
Wj	The node of the final destination of the aircraft
P	The global starting point
Q	The global target point
M	The linear distance between the current position and the global target point
s	Current starting point
D	Path length
	Change of angle
H	Distance off course
T	Run time
	The turning point
	Repulsive potential field
	Repulsion scale factor
	Distance from obstacle to aircraft
	The range of influence of the obstacle