用于移动机器人听觉导航的光纤麦克风阵列研制

Development of Fiber-Optic Microphone Array for Acoustic Navigation of Mobile Robots

听觉感知是移动机器人不可或缺的功能,传统电声式麦克风灵敏度较低、易受电磁干扰,致使移动机器人听觉感知能力较差,使用受到很大限制。采用自制的Fabry-Perot干涉式(FPI)光纤麦克风代替电声式麦克风,在市售移动机器人平台上构建了四元十字型光纤麦克风阵列,设计了基于FPGA的信号处理与声源定位算法程序,实现了机器人听觉感知与被动式声导航功能。介绍了FPI光纤麦克风的工作原理,测试并比较其与市售驻极体麦克风的灵敏度;优化了基于FPGA的声达时差(Time Difference of Arrival,TDOA)定位算法,完成了移动机器人搭载声源定位系统的设计与集成。实验表明移动机器人搭载的光纤麦克风声源定位系统具有水平全向声源定位功能,在平均距离为6.60 m的情况下,室内定位方位角平均误差为1.54°、距离平均误差为0.09 m;室外定位方位角平均误差为1.84°、距离平均误差为0.16 m,具有较高的精确度与稳定性;且移动机器人均能准确到达声源处完成声导航功能,具有很强的实用性与广阔的应用前景。

Auditory perception is an indispensable function of mobile robots.Electroacoustic microphones have the disadvantages of low sensitivity and susceptibility to electromagnetic interference,which greatly limits the use of mobile robots.In this paper,a Fabry-Perot interferometric(FPI)optical fiber microphone is used to replace the electroacoustic microphone,and a cross-type array is constructed on the mobile robot platform.The FPGA-based signal processing and sound source localization algorithm software is designed to realize the functions of robot auditory perception and passive acoustic navigation.Firstly,the working principle of FPI fiber optic microphone is introduced,and its sensitivity with electret microphone is tested and compared.Then,the FPGA-based time difference of arrival(TDOA)localization algorithm was optimized,and the design and integration of the sound source localization system on the mobile robot was completed.Experiments show that when the average distance is 6.60 m,the average error of indoor positioning azimuth is 1.54°and the average error of distance is 0.09 m and the average error of outdoor positioning azimuth is 1.84°and the average error of distance is 0.16 m.The robot can accurately reach the position of the sound source.All these show that the system has strong practicability and broad application prospects.