Technology Research In UAV Path Planning In Complex Environment

UAV(unmanned Aerial Vehicles) route-planning is a high-tech which has developed rapidly in recent years,, having been widely used in civil and military fields, and has achieved a huge success in these areas. However, with the increasingly complex environment and increasing uncertainties of the mission, UAV route- planning requirements are getting higher and higher. So, the key issue of unmanned aircraft route planning is to establish a good environment model and to adopt efficient programming algorithm.Route-planning research background, research status and applications in various fields are briefly described in this paper firstly; and then, many algorithms,for example,algorithms of terrain simulation, algorithms of threats simulation, and algorithm of equivalents terrain fusion are achieved by using function method, aiming at UAV route-planning’s requirements for digital map; and preprocessing algorithm for digital terrain makes the smoothed equivalent digital terrain meet the requirements of UAV climb performance and turning curvature, so that the scanned time in the process of UAV route-optimization becomes shorter, while turning the threat avoidance into terrain avoidance to deal with, simplifying the route-optimization algorithms, and meeting the real-time requirements.Then absorbing the core idea of the particle swarm algorithm, which is the typical of swarm intelligence algorithm, considering inertia weight factor in the speed-evolution-equations for discrete domain search problem, while Simulated Annealing operation is introduced in determining the PSO algorithm parameters, which forms an improved particle swarm optimization algorithm, which make up parameter values depending on experience and deficiency of easily fall into the local optimal(i.e. premature)for the conventional PSO algorithm, improving their ability of global optimization, and then to solve UAV complex route planning.In addition, this paper presents a hierarchical route planning concept, planning a global reference track before take-off, when a sudden threat arises, local route planning will be done on the basis of the reference trajectory. And track evaluation functions are built using different values of weights in three factors, such as terrain threat, performance limitations and flight restrictions.Finally, this paper establishes a equivalent digital map using matlab 2013 a, and does the simulation respectively about global path-planning and local path-planning of sudden threat.This paper also imitates decision-makers to use different strategies to get UAV path in dealing with sudden threats by changing the weight value of the fitness function.The results of simulation experiments of global path-planning and local path-planningindicate that,when using a different initialization method, or changing the parameters of the fitness function, the method is a effectively way to improve the quality of the flight path,and also makes a quick response for unexpected threats. In addition, it provides a more extensive selection for decision-makers on the choice of strategies.