无人机声学定位技术综述

Review for UAV Acoustic Positioning

近年来“低小慢”无人机的过快增长,肆意飞行严重威胁了城市安防和公众安全。如何在复杂低空环境下有效地定位“低小慢”无人机,成为亟待解决的社会问题。由于雷达、光电探测等手段存在盲区、辐射强度弱等问题,导致近距离定位效果不理想。声学定位因其传感器成本低,阵列布放形式灵活,近距离定位误差较小,有效地补充了雷达、光电等定位方法的缺陷。文中对无人机声学定位方法进行了综述,分析了无人机噪声的频谱,发现这些噪声信号具有很强的线谱结构,这些线谱具有丰富的谐频成分和很高的信噪比,且抗干扰能力较强。首先结合旋翼噪声的声学特性得出了从时域角度和频域角度定位无人机的可行性;接着介绍了声学定位方法的原理,并给出了算法仿真结果,比较了时域和频域定位方法的均方根误差;然后统计了近年来国内外高校基于声学定位的低空无人机的实现方法,发现基于到达时间差(TDOA)的平面阵列使用最广,定位效果较好;最后对未来低空无人机声学定位进行了展望。

In recent years,the rapid growth of“low,small and slow”UAVs(Unmanned Aerial Vehicles)and their uncontrolled flying have posed a serious threat to urban security and public safety.How to effectively locate“low,small and slow”UAVs in complex low-altitude situations has become an urgent social problem.Due to the blind spot and weak radiation intensity of radar and photoelectric detection,the effect of close range positioning is not ideal.Acoustic positioning,effectively compensates for the disadvantages of radar and photoelectric positioning methods due to its low sensor cost,flexible array placement and small positioning error.This paper summarized the acoustic positioning methods for UAVs.The spectrum of UAV noise was analyzed and it found that these noise signals have a strong line spectrum structure.These line spectra are rich in harmonic frequency components,have a high signal-to-noise ratio and are highly resistant to interference.Firstly,the acoustic characteristics of rotor noise were integrated to derive the capability of locating the UAV from both time and frequency domain perspectives.Secondly the principles of acoustic localization methods were introduced and the algorithm simulation results were given.It also compared the root mean square error of the time domain and frequency domain localization methods.Next,the implementation methods of acoustic-based localization of low-altitude UAVs in universities at home and abroad in recent years were counted,and it found that the planar array based on time difference of arrival(TDOA)is most widely used and has better localization effect.Finally,acoustic localization of low-altitude UAVs in the future was prospected.