Research On Detection Algorithm Of Foreign Object Debris Based On Millimeter Wave Radar

The existence of foreign object debris(FOD)is a major potential safety hazard for aircraft,which not only causes huge economic losses,but also may endanger life safety.Therefore,the prevention of FOD is of great security significance,and FOD detection is one of the common measures to prevent FOD.FOD detection technology is mainly used to detect weak stationary target under strong ground clutter.This paper takes FOD detection as the research background,firstly,four radar clutter models are modeled,and the FOD detection algorithm based on radar is mainly discussed.In order to realize the automatic detection of FOD,several CFAR detection algorithms are proposed in time domain and space domain respectively.The main research work of this paper is as follows:(1)The scene of FOD detection is divided geometrically,the model of linear frequency modulate continuous wave signal is introduced,and the stretching operation is explained.Four commonly used radar clutter models and their applicable scenarios are introduced.Two clutter modeling methods are used to simulate clutter models,the simulation results are in good agreement with the theoretical clutter characteristics.(2)Since the traditional constant false alarm rate(CFAR)detection technology has the problem of poor detection performance at low signal to clutter ratio(SCR),a CFAR detection algorithm with fixed window length based on nonlinear shrinkage map and a two-level thresholds clutter-map detection algorithm based on nonlinear shrinkage map are proposed.Clutter suppression is realized by constructing nonlinear shrinkage map function.The false alarm probability and detection probability of the corresponding algorithm are derived,and the performance of the algorithm is analyzed.Simulation experiments and measured data show that the proposed algorithm has good detection performance in weak target detection.Compared with the classical clutter map CFAR,the detection probability of the proposed algorithm is improved by about 15%under the condition of low SCR.(3)The traditional CFAR detection algorithms in spatial domain play their potential in FOD detection,but the performance of these methods is degraded in the complex clutter background of airport runway.To address this issue,this paper proposes a detection algorithm based on entropy of power spectrum.The energy distribution of radar echo is analyzed,and the entropy feature of power spectrum is led into target detection.Simulation results show that contrast with the traditional spatial CFAR,the proposed algorithm can improve the detectability of targets,and the detection probability is increased by about 8%.