基于单周期互相关滤波的超声波TOF检测方法  

Accurate ultrasonic TOF measurement method based on monocycle cross-correlation filtering

作　　者：陈建[1] 孙晓颖[1] 林琳[1] 王波[1] 

机构地区：[1]吉林大学通信工程学院,长春130022

出　　处：《仪器仪表学报》2014年第3期664-669,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61171137);吉林省科技发展计划(201201029)资助项目

摘　　要：针对超声波渡越时间精确检测的要求,提出一种基于单周期相关滤波法的超声波渡越时间精确检测算法。该方法采用驻极体电容麦克风(ECM)接收超声波信号,利用单周期正弦波互相关滤波算法抑制低于20 kHz的声音信号干扰,在经相关滤波处理后的超声波信号缓冲区内,搜索得到超声波信号的峰值点,计算相邻周期峰值变化值,以峰值变化最大值为超声波到达判断依据,通过直线拟合方法计算出超声波的渡越时间。该方法采用单周期互相关滤波算法,克服了传统相关算法计算量大的缺点。在较低信噪比的条件下,仍具有较高的检测精度。该方法具有计算量小、实时性好、精度高等优点,为超声波测距、机器人导航、目标跟踪与定位、流量测量等超声波高精度检测提供一种计算量低、精度高的检测方法。仿真与实验结果验证了算法具有较高的精度和实时性。Aiming at the requirement of accurately measuring ultrasonic time of flight （TOF）,a high precise measurement method for ultrasonic time of flight was proposed based on monocycle cross-correlation filtering.The method uses electret capacitor microphone （ECM） to receive ultrasonic signal,adopts monocycle sine wave cross-correlation filtering algorithm to suppress audio signal interference below 20 kHz.After cross-correlation filtering,searching is performed in the ultrasonic signal data buffer to obtain the peak point of the ultrasonic signal and calculate the peak variation values in adjacent cycles.The maximum peak variation is taken as the judgment criteria of the ultrasonic arrival,and the straight line fitting method is adopted to calculate the ultrasonic time of flight.Using monocycle cross-correlation filtering algorithm,this method overcomes the shortcoming of large computation of traditional correlation algorithm.In low SNR condition,the method still has high detection accuracy.The proposed method features low computation,good real-time performance and high precision,which provides a good measurement method for high accuracy ultrasonic measurement in ultrasonic ranging,robot navigation,target localization and tracking,and flow measurement.Simulation and experiment results show the proposed method has high accuracy and good real time capability.

关 键 词：渡越时间 相关滤波 超声波 过零点检测 

分 类 号：TN911.72[电子电信—通信与信息系统]