For the constant false alarm rate(CFAR)detection problem of active sonar in complex environment and propagation channel,an automatic CFAR detection method of active sonar based on hierarchical filters was proposed.Fir...For the constant false alarm rate(CFAR)detection problem of active sonar in complex environment and propagation channel,an automatic CFAR detection method of active sonar based on hierarchical filters was proposed.Firstly,based on the spatial response characteristics of the array and the morphological characteristics of the target echo,a spatio-temporal filter was designed to remove the background noise and reverberation signal.Then,a linear and nonlinear combined spatial filter were designed to extract the energy accumulation area of the active sonar sonogram.Finally,the multi-dimensional features such as the spatial azimuth distribution of the target echo,the shape matching and the signal-to-noise ratio between the accumulation point and the adjacent background were calculated and fused to realize the target detection.Numerical simulation and sea test data show that,the probability of automatically detecting targets by this algorithm is larger than 85%in three typical cases,and this algorithm can detect targets when the background noise fluctuates greatly,showing that the algorithm is more robust.展开更多
Harris hawks optimization(HHO)algorithm is an efficient method of solving function optimization problems.However,it is still confronted with some limitations in terms of low precision,low convergence speed and stagnat...Harris hawks optimization(HHO)algorithm is an efficient method of solving function optimization problems.However,it is still confronted with some limitations in terms of low precision,low convergence speed and stagnation to local optimum.To this end,an improved HHO(IHHO)algorithm based on good point set and nonlinear convergence formula is proposed.First,a good point set is used to initialize the positions of the population uniformly and randomly in the whole search area.Second,a nonlinear exponential convergence formula is designed to balance exploration stage and exploitation stage of IHHO algorithm,aiming to find all the areas containing the solutions more comprehensively and accurately.The proposed IHHO algorithm tests 17 functions and uses Wilcoxon test to verify the effectiveness.The results indicate that IHHO algorithm not only has faster convergence speed than other comparative algorithms,but also improves the accuracy of solution effectively and enhances its robustness under low dimensional and high dimensional conditions.展开更多
基金supported by the China State Shipbuilding Corporation Equipment Pre-Research Joint Fund(6141B03090103).
文摘For the constant false alarm rate(CFAR)detection problem of active sonar in complex environment and propagation channel,an automatic CFAR detection method of active sonar based on hierarchical filters was proposed.Firstly,based on the spatial response characteristics of the array and the morphological characteristics of the target echo,a spatio-temporal filter was designed to remove the background noise and reverberation signal.Then,a linear and nonlinear combined spatial filter were designed to extract the energy accumulation area of the active sonar sonogram.Finally,the multi-dimensional features such as the spatial azimuth distribution of the target echo,the shape matching and the signal-to-noise ratio between the accumulation point and the adjacent background were calculated and fused to realize the target detection.Numerical simulation and sea test data show that,the probability of automatically detecting targets by this algorithm is larger than 85%in three typical cases,and this algorithm can detect targets when the background noise fluctuates greatly,showing that the algorithm is more robust.
基金supported by the National Natural Science Foundation of China(61872126)。
文摘Harris hawks optimization(HHO)algorithm is an efficient method of solving function optimization problems.However,it is still confronted with some limitations in terms of low precision,low convergence speed and stagnation to local optimum.To this end,an improved HHO(IHHO)algorithm based on good point set and nonlinear convergence formula is proposed.First,a good point set is used to initialize the positions of the population uniformly and randomly in the whole search area.Second,a nonlinear exponential convergence formula is designed to balance exploration stage and exploitation stage of IHHO algorithm,aiming to find all the areas containing the solutions more comprehensively and accurately.The proposed IHHO algorithm tests 17 functions and uses Wilcoxon test to verify the effectiveness.The results indicate that IHHO algorithm not only has faster convergence speed than other comparative algorithms,but also improves the accuracy of solution effectively and enhances its robustness under low dimensional and high dimensional conditions.
