Research On Passive Location Method Of Moving Target In Multi-path Environment

The passive localization method based on fuzzy function combines the acoustic field environment and signal processing technology.Compared with the traditional signal processing technology,this method makes full use of the information contained in the acoustic field environment and has better processing performance.The passive localization method of fuzzy function has broad application prospects in the field of passive localization of small-scale platform targets.This paper mainly studies the passive localization of sound source target based on fuzzy function in multi-path environment.Firstly,the paper briefly introduces the basic principle of fuzzy function localization method.Then,the localization performance of three kinds of commonly used fuzzy function processors is theoretically analyzed,and an improved multiconstraint fuzzy function processor is proposed for the shortcomings of large fuzzy interval,and low localization accuracy of the original multi-constraint fuzzy function processor.Constraining the processor,the method can effectively suppress side lobe interference in the positioning result by adding a suitable diagonal matrix to the covariance matrix of the measurement field,and can also appropriately increase the environmental mismatch resistance of the method.In order to further improve the localization effect of the fuzzy function localization method,the paper studies the vector fuzzy function localization method using the particle vibration velocity based on the sound pressure fuzzy function localization method,and simulates and analyzes their respective performances.Compared with the simulation results of the sound pressure fuzzy function localization method,the vector-based fuzzy function localization method has better localization performance.Then,this paper studies the effect of environmental mismatch on the performance of fuzzy function localization methods.Since there is always a deviation between the established copy field and the actual measured acoustic field,the problem of environmental mismatch is common in the process of sound source target localization.In this paper,the environment mismatch is simulated by changing the parameters of the acoustic field model,which is used to analyze the influence of different environment parameters on the positioning performance of different processors.The simulation analysis of the performance impact of fuzzy function localization method under the conditions of sound velocity gradient,water depth,bottom topography and substrate mismatch is emphatically carried out.After the above positioning simulation analysis,based on the passive target positioning problem in the multi-path environment studied in this paper,before the actual shallow water test,the paper firstly carried out the fuzzy function localization in the strong multi-path environment of the reverberation pool.Algorithms and experimental studies.In order to solve the problem of fast calculation of the three-dimensional acoustic field in the reverberation pool,based on the virtual source method,an analytical expression for calculating the threedimensional acoustic field in the reverberation pool is deduced,and the selection of the pool boundary parameters in the analytical expression is discussed.Thereby,the physical field model of the reverberation pool is established.The method uses spatial geometry to analyze the reflection of sound rays in the reverberation pool intuitively,which simplifies the boundary problem of the reverberation pool and avoids the problem of establishing an ideal underwater diffusion field.Through simulation and experiment,the correctness of the sound pressure calculation result of this method is verified.Then,in the reverberation pool environment,the fuzzy function localization experiment was carried out by using the multi-way arrival time delay.The experimental results show that,based on the fuzzy function localization method,the sound source in the reverberation pool can be accurately 3D localized with a single hydrophone.Finally,based on the above research results,the experimental data on the lake were processed.The processing results show that the fuzzy function-based localization method can effectively locate the sound source target in the lake.Compared with the scalar fuzzy function localization method,the vector-based fuzzy function localization method has better localization performance and robustness,and has a broader application prospect.