Based On Complex Three-dimensional Environment Constraints UAV Route Planning

UAV is playing a more and more important role in modern national defense mission, and trajectory planning as the core role of flight mission trajectory, is growing more and more vital, becoming a subject that all countries strive for researching. The so-called trajectory planning, is that without artificial intervention or under little artificial intervention, according to the constraint conditions such as aircraft performance, environmental influence, the planning system that automatically calculate the UAV optimal flight trajectory and guarantee the UAV to accomplish the mission safely and efficiently. The existing planning method analyze the process on the basis of planar space or using the elevation as an attribute in most cases, so the real three-dimensional region couldn’t be expressed preferably. As to the complex surroundings and other constraint conditions when the UAV is executing real mission, so it is necessary to exclude all kinds of threats in trajectory planning, in order to obtain the rational, efficient and secure UAV flight trajectory.This paper mainly studies the security and the optimality of trajectory planning mission, including the following aspects:1. Inducing the overall process of the trajectory planning, analyzing the problems needed to pay attention to during the planning process, that is evading threats and the optimal trajectory generation, and submitting specific implantation plan.2. Constraint conditions fall into two kinds:aircraft performance constraint condition and environmental influence constraint condition, as the basis of the trajectory planning mission. The aircraft performance constraint condition includes flight distance constraint, maximum corner constraint, and minimum step length constraint. The environmental threat constraint condition includes detection threat, firepower threat, terrain threat, and no-fly zone threat.3. Modeling each threat in order, as to the UAV would encounter detection threats such as radar and electromagnetism or firepower threats such as missile and anti-aircraft gun, detection threats modeling is on the basis of detecting radius, firepower threats modeling is on the basis of fire radius. In addition, there are other threats such as no-fly zone threat and so on, and modeling according to the specific situation.4. By selecting the appropriate secure threshold value, the UAV safe zone could be calculated, on the basis of safe zone, the optimal trajectory could be generated by the improved A*algorithm.The evaluation of the trajectory planning, including facts such as length, height, visibility, analyzing the optimality of the trajectory synthetically.At last, apply the above trajectory planning method to the trajectory planning instance, getting the optimal trajectory by considering each fact synthetically, by the evaluation of the trajectory planning, it could verify that the generated trajectory is reasonable, and the method is doable.