Research On Methods Of Path Planning And Replanning For UAVs

With the development of the aviation technology and electronic technology,the UAVs got a great advance in its capability, they have a broad future prospectsin military and civil application. Compare with the aircraft with a pilot, the UAVshave a smaller size, greater flexibility, lower prise, and the UAVs don’t suffer thedeath of soldiers, it is also easier for UAVs to take off. As a key technology of theUAV’s autonomous navigation, the path planning technology has become researchhot point of the UAVs. The path planning of UAVs is a complex problemincluding the consideration of arriveing time, fuel expend, threat and availableairspace, then give a optimal or sub-optimal solution of future flight path. Thisthesis focus on the path planning method for UAVs and on-line path re-plan forUAVs when emergency happens.This thesis give a detailed research on the development of autonomous controltechnology all over the world, give a analysis on the main direction andcharacteristic of the research of UAVs autonomous control technology, give aresearch of the development and the present situation of the UAVs autonomous pathplanning and re-plan.This thesis give a detailed introduction of UAVs path planning problem andbuild a reasonable math model of the problem. Separately present the expressionmethod of airspace and flight path. Give a basic constraint of flight path and theevaluate method of the path.Based on the threat from natrual environment and the enemy when the UAVexecutes the task, describe the method the UAV uses to deal with the threat andestablish the models of radar threat and the air defense’s threat.The paper describes the exsiting algorithm of UAV’s route planning, becauseof the characteristics of PSO’s capacity and less parameters but high speed ofconvergence, it was chosen to be the algorithm of route planning,and the paperstudies the problem of the route planning baseded on PSO and gives a method ofminishing inertia linearly to increase the speed of convergence.Based on the uncertainty of the environment in which the UAV flies and thesforzando of enemy or the new threat of air defense, the paper gives a method of the route planning baseded on PSO and simulates and anlysises. The result ofsimulation shows that this method is real-time.