An efficient algorithm for path-planning and collision avoidance of UAVs in multi-layer low-altitude airspace.

The use of air taxi under the concept of urban air mobility (UAM) is a new mode of transportation that can significantly reduce urban traffic, especially in the metropolis area. The operation of air taxi is studied based on the path planning and collision avoidance in low altitude airspace for UAVs. To solve this challenge, First, by using the A* algorithm, the path of each individual UAV is created by avoiding obstacles and restricted area. Then an optimization problem has been formulated in the form of integer linear programming with absolute value to eliminate the possibility of any collision between UAVs along the path. The idea of this problem is to change the altitude layer of UAVs in the conflict points. Comparing the results of this approach with other state-of-art approach in this context shows the superiority of this algorithm both in terms of travel time and program run time.