Research On Low-altitude Unmanned Aerial Vehicle Detection System Based On Small Microphone Array

With the development of low-flying unmanned aerial technology,low-altitude unmanned aerial vehicles have been widely used in various fields,such as material transportation,disaster relief and agricultural irrigation for its advantages of compact,convenient,flexible and simple operation.However,the rapid increase in the number of UAVs has also exposed many problems,such as prying on personal privacy,endangering public security,and disclosing state secrets.According to the social situation of lacking effective supervision of low-altitude UAVs,this paper put forward a low-altitude UAVs detection method based on acoustic detection technology.Developing a low-altitude UAVs detecting system based on small microphone array.Providing a solution for low altitude security of cities.The low altitude UAVs detection system mainly contains two parts:the embedded hardware data acquisition platform and the location algorithm.The embedded hardware data acquisition platform using MEMS microphone to acquire the sound of UAVs.The main control chip uses a STM32F407ZET6 high performance microchip based on ARM Cortex-M4 kernel which contains many data transmission interfaces.The system can collection the flying sound data of UAVs with different sampling parameters.This paper uses the time difference of arrival(TDOA)estimation algorithm as the location algorithm.The time difference of arrival is obtained by the generalized cross correlation(GCC)algorithm,and then use the geometric method to calculate the orientation of the sound source.At last,this paper analyzed the detecting distance and angle estimation performance of low-altitude UAVs detection system,giving the detecting distance parameter and the accuracy of angle estimation.In addition,this paper also researched three environmental factors that may make some difference to the detection system,such as electromagnetic radiation,wind noise and temperature and humidity.The influence of the three different environmental factors on the performance parameters of the low-altitude UAVs detection system is qualitatively analyzed.