Research On Airborne Radar Target Detection And Track Planning Methods

The parameters of the radar pulse repetition frequency group and route are directly related to the detection performance of the early warning aircraft against the target in the background of clutter.On the one hand,the geographical environment of the radar is different under different routes.The range gate,Doppler gate and backscattering power of the same ground clutter will vary with the current carrier's radial distance,azimuth,relative motion status,main beam pointing,etc.which affects the detection performance of the radar for moving targets in certain directions and distances.On the other hand,the airborne early warning radar often adopts the multi-pulse repetition frequency working mode of medium and high pulse repetition frequency,and the specific value of the multi-pulse repetition frequency determines the ambiguity of clutter and target in the range-Doppler domain,together with the clutter distribution,determines the target detection dead zone after two-dimensional deblurring.In order to improve the target detection performance of the radar,the early warning aircraft can perform real-time dynamic trajectory planning and optimization of working parameters based on the temporarily acquired detection scene information,to reduce the target detection dead zone as much as possible.In addition,when multiple drones cooperate in reconnaissance of the mission area,the conventional method divides the area to be searched into several sub-areas,and then uses the "Z" route coverage and search targets in the sub-areas.This method not only has the shortcomings of long flight path,low reconnaissance efficiency,and high fuel consumption,but also is difficult to handle possible obstacles,a few drones are shot down or machine failures,and new drones join the work.Coping with new solutions.Aiming at the problem of target detection performance prediction,trajectory and working parameter selection assisted by geographic knowledge,this paper proposes a genetic algorithm-based early warning aircraft trajectory planning and re-frequency group optimization method.Aiming at the problems in multi-UAV collaborative area coverage search,a trajectory planning method for multi-UAV collaborative area coverage search is proposed.The main work includes: 1.Research on knowledge-aided EWA track planning and Pulse Repetition Frequency group optimization methods.First,considering the situation that clutter cannot be completely suppressed and affect the radar target detection performance,a multi-scene clutter simulation method containing different geographical environmental factors is studied.Furthermore,the evaluation method of radar detection performance is studied.Next,the cumulative value of the target discovery probability in the detection blind area map is used as the detection performance evaluation index,and a calculation method of the detection performance evaluation index at a single track point is formed.On this basis,a track planning method and a re-frequency group optimization method are proposed to improve the target detection performance,and a combination of track planning and re-frequency group optimization is proposed to further improve the detection performance,and a genetic algorithm is used to find the best.The simulation results show that this method can get better flight path and transmit re-frequency group,which can effectively reduce the detection blind zone.2.Research on track planning method of multi-UAV cooperative area search.First,the basic idea of multi-UAV area search dynamic trajectory planning is analyzed,and constraints such as the maximum turning angle and minimum turning radius of the UAV are considered.Then,the corresponding solutions are proposed for unexpected situations such as flying out of the boundary of the mission area and collision obstacles that may exist in the UAV mission search process.On this basis,a track planning method for multi-UAV collaborative area search is proposed and implemented based on modern classic intelligent algorithms.This method can not only plan a reasonable trajectory for multiple drones,but also adjust the route in real time under the conditions of obstacles blocking,a few drones being shot down or machine failures,new drones joining the work,etc.The advantages of small,high efficiency,flight path and complete coverage of the area.