基于频谱分析的压缩空气泄漏直射和反射超声的识别  

Distinguishing between directed and reflected ultrasonic signals generated by a compressed air leak source based on spectral analysis

作　　者：廖平平[1] 蔡茂林[1] 许启跃[1] 石岩[1] 

机构地区：[1]北京航空航天大学自动化科学与电气工程学院,北京100191

出　　处：《振动与冲击》2013年第8期58-62,共5页Journal of Vibration and Shock

基　　金：国家科技支撑计划(2011BAF05B04)

摘　　要：介绍了气动系统中压缩空气泄漏超声检测的原理,分析了由反射超声信号导致的错误检测问题,并提出通过识别反射超声信号的方法来解决此问题;对直射和反射超声信号进行测量实验研究,发现并分析了直射和反射超声信号在频谱图形状上存在的明显区别;通过设计识别算法,得到可识别反射超声信号的反射特征系数(Reflectance Char-acteristic Coefficient,RCC);经实例计算发现:直射超声信号的RCC值在100以下,反射超声信号的RCC值在200以上。该结果对压缩空气泄漏检测中有效的识别出反射超声信号、避免由反射超声波导致的检测错误具有重要的实用价值。The principle of compressed air leak ultrasonic detection in pneumatic systems was introduced. The detection mistakes caused by a reflected ultrasonic was analyzed and a method solving this problem through distinguishing a reflected ultrasonic was proposed. Compressed air leak directed and reflected ultrasonic signals were studied through measurement tests. The obvious differences between the spectra of directed and reflected ultrasonic signals were found and analyzed. An algorithm for distinguishing a reflected ultrasonic was designed and using it the reflectance characteristic coefficient （RCC） of the reflected ultrasonic was calculated. From the case study, it was shown that the RCC value of a directed ultrasonic signal is below 100 while that of a reflected ultrasonic signal is above 200. The results were valuable for distinguishing a reflected ultrasonic and avoiding detection mistakes caused by a reflected ultrasonic in ultrasonic leak detection.

关 键 词：压缩空气 泄漏 超声检测 直射 反射 反射特征系数 

分 类 号：TH412[机械工程—机械制造及自动化]