Probabilistic approach in path planning for UAVs

This paper introduces a probabilistic approach to the problem of mission planning for UAVs (Unmanned Aerial Vehicles) flying through an area of multiple sources of threat. As the first step, this new approach is used in path planning. It is assumed that the probabilistic map of the area of operation is available during the mission. Probabilistic map is defined as the risk of exposure to the sources of threat as a function of position. In the path planning, the objective is to go to a target location along the shortest possible path with an acceptable probability of getting disabled or along an acceptably long path with the lowest possible probability of getting disabled. Depending on the definition of threat, a UAV is considered "disabled" by a source of threat when it is detected, hit or shut down. The conditional probability of a UAV getting disabled under the condition that it follows a certain path is defined and formulated based on the probabilistic map of the area. Then, two strategies that lead a UAV to the target through the area of operation is developed. The strategies use the local information of the probabilistic map and the information about the location of the target. They are parameterized to change the weighting on finding a shorter path or finding a path with smaller probability of getting disabled. Finally, the strategies are implemented in a case study to illustrate the application of the probabilistic approach. The paper includes a discussion on using the probabilistic approach in other phases of mission planning for multiple UAVs.