用于减小PMUT“盲区”的回波检测方法  

Echo Detection Method for Reducing"Blind Area"of PMUT

作　　者：王光华 张玉超 胡益民 苗斌[2,3] 张士钦 周红宇 赵祥永 李加东 WANG Guanghua;ZHANG Yuchao;HU Yimin;MIAO Bin;ZHANG Shiqin;ZHOU Hongyu;ZHAO Xiangyong;LI Jiadong(School of Mechanical and Electrical Engineering,Changchun University of Science and Technology,Changchun 130012,China;Suzhou Institute of Nano-Tech and Nano-Bionics(SINANO),Chinese Academy of Sciences,Suzhou 215123,China;Key Laboratory of Multifunctional Nanomaterials and Smart Systems,Chinese Academy of Sciences,Suzhou 215123,China;Mathematics and Science College,Shanghai Normal University,Shanghai 200234,China)

机构地区：[1]长春理工大学机电工程学院,吉林长春130012 [2]中国科学院苏州纳米技术与纳米仿生研究所,江苏苏州215123 [3]中国科学院多功能材料与轻巧系统重点实验室,江苏苏州215123 [4]上海师范大学数理学院,上海200234

出　　处：《压电与声光》2023年第3期363-367,共5页Piezoelectrics & Acoustooptics

基　　金：国家自然基金资助项目(编号:62074159);国家重点研发计划(项目编号:2021YFB3201600);国家自然科学基金资助项目(编号:52172005)。

摘　　要：收发一体式压电微机械超声波换能器(PMUT)的接收信号存在较长的拖尾,导致近场原始回波难以区分,造成测量盲区,对此提出了一种在拖尾段识别回波信号的方法。该方法利用解调对数放大器非线性压缩接收信号并进行包络处理,得到拖尾段具有明显极值点特征的包络曲线,并通过包络曲线极值点识别回波峰值。选取8组谐振频率不一的PMUT器件对该方法进行测试验证。结果表明,在最远测距大于300 cm的情况下,测量盲区缩减至10 cm附近,该方法具有一定的有效性与普适性。In view of the problem that the receiving signal of the integrated piezoelectric micro mechanical ultrasonic transducer(PMUT)has a long tail,which makes it difficult to distinguish the near-field original echo and causes a blind area in measurement,a method to identify the echo signal in the tail section is proposed in this paper.The method uses demodulated logarithmic amplifier to compress the received signal nonlinearly and carry out envelope processing to obtain the envelope curve with obvious extremum point characteristics in the trailing section.The peak value of echo is identified by the extremum point of envelope curve.Eight groups of PMUT devices with different resonant frequencies were selected to test and verify the method.The results show that the measuring blind area is reduced to around 10 cm when the farthest distance is more than 300 cm,which demontrates that the proposed method has certain effectiveness and universality.

关 键 词：PMUT 收发一体式 拖尾 测量盲区 极值点 峰值 

分 类 号：TN384[电子电信—物理电子学] U284.77[交通运输工程—交通信息工程及控制] TP312[交通运输工程—道路与铁道工程]