Abstract: For earthquake scenarios, the article proposes a path planning algorithm for multi drone collaborative search. This method is an improved path search optimization algorithm based on depth first search and spanning tree ideas. The algorithm is divided into two steps. The first step can obtain all reasonable search paths of UAV under the specified step constraint. The second step can obtain the specified path combination number with high search probability under the condition of the specified number of UAVs. The calculation results show that the proposed path search algorithm guarantees the exhaustiveness and uniqueness of the path. Among the search path combinations satisfying the constraint conditions, the route with the highest target probability is found to mainly cover the densely populated residential areas, which is consistent with the reality. Moreover, through experimental simulation, the UAV can return more disaster site information by taking photos within the specified time, providing more accurate direction for the search and rescue team to make rescue plans.

Key words: unmanned aerial vehicle coordination, optimal search path, depth-first search, spanning tree, searching probability