Study On The Two-ear Positioning Model Based On Bats

Nature is the best teacher of man,scientists use sound waves to locate navigation in less than 100 years,but the nature of bats in human civilization before the evolution of the use of ultrasound for positioning and navigation skills.They use their sonar system to analyze the sound waves to achieve their own navigation and positioning of prey.In this paper,a two-ear passive acoustic positioning system and a single mouth dual-ear Active acoustic positioning system are designed and completed by imitating the bat's binaural positioning mechanism and combining with the microphone array algorithm.Firstly,this paper introduces and analyzes the GCC,LMS and MUSIC algorithm,and simulates and tests various algorithms,and obtains the estimation performance of various algorithms in the noisy environment.In addition,this paper analyzes the conflict between the two-ear location and the spatial sampling theorem of bat using subspace algorithm,by imitating the bat's ear-regulating auricle and using wideband FM signal-assisted positioning method,the restriction of space sampling theorem is introduced by means of adjusting the spacing of the elements and using wideband FM signal.The limiting conditions of the spacing adjustment and the frequency regulation of the array are given through mathematical deduction.Secondly,a set of dual high speed continuous audio sampling equipment is designed with STM32 Core board and MEMS microphone,and the software and hardware environment is built for the verification of sound source localization system.The device can meet the storage speed requirement of 400KHz dual synchronous AD sampling with a sampling accuracy of 12 bits.In addition,in order to match the high-speed continuous AD sampling,the SDIO interface and the ping-pong buffering mechanism are used to save the audio signal.The current popular embedded Fatfs file system is transplanted,which simplifies the process of collecting signal.The interface used by this system has ADC,TIMER.SDIO,DMA and FATFS,which can provide some reference for the Low-cost miniaturized continuous audio acquisition system.Finally,a lot of practical tests are done based on the hardware environment.It is verified that the two-ear model can estimate the incident angle using the improved music algorithm mentioned above,and the success rate is higher than that of the GCC algorithm.Based on the passive two-ear positioning system,an active dual-ear positioning system is designed,and the results show that the active binaural positioning system can be used in the active positioning of the target in space when the echo is strong enough to provide a new idea for active sonar technology.