Abstract: A path planning scheme based-on different threats for unmanned combat air vehicles is developed. Firstlythe principle to select path in local area with different threats is established, and a new approach to create the pathdiagram by different threats is presented. Secondly the evolutionary algorithms based-on graph model is described.Results of simulation show that this path planning method can be used to generate an optimal path without smoothness. Thus a breakthrough has been made for the initial path planning by using the Voronoi diagram only for samethreats.

Key words: path planning, unmanned combat air vehicles, graph model, evolutionary algorithms