采用串口传输大量的超声导波回波数据时,不仅传输速度慢,且易丢失数据,无法实时、准确检测;在超声导波激励/接收仪的基础上开发了USB2.0接口与仪器进行高速实时通信的上位机采集分析软件;软件利用标准API函数通过USB驱动操纵仪器,可设置仪器的激励频率、采样频率、激励电压等参数,且能进行手动/自动扫频,从而选取合适激励频率;软件应用于导波扫频实验中,可准确获取合适的激励频率,传输速率达63.883Mbps/s,满足高速、实时、准确采集数据的要求;其内部集成的小波降噪、FFT、信号包络、短时傅里叶变换功能,可有效提高导波信号的信噪比,分析其频率成分,准确抽取导波信号的波包峰值等;此软件应用于实际的钢杆扫频实验中,可准确定位合适的激励频率,增强了超声导波的实用性。
At present, the software for detecting and analyzing ultrasonic guided wave are less, and mostly the serial ports are used to transmit data. The transmission speed is so slow, and the data are easily lost, when using serial ports to collect a large amount of data of ul trasonic guided waves, so realtime, accurate detection is impossible. A PC data acquisition and analysis software has been developed based on ultrasonic guided wave excitation and receiving apparatus, which can communicate with the instrument through the USB2.0 bus highly and in real time. Software uses standard API functions to manipulate the instrument through USB driver, can set the excitation frequency, sampling frequency, voltage and other parameters of instrument, and can scan frequency automatically or manually to select suitable excita tion frequency for ultrasonic guided waves. The software is used in frequency sweep test for guided waves, it can accurately select the appro priate excitation frequency, and the transmission rate is up to 63. 883Mbps/s, meeting highspeed, real time, and accurate data collection requirements; wavelet noise reductions, FFT, signal envelope and shorttime Fourier transform functions integrated into software can ef fectively improve guided waves signal to noise ratio, analysis frequency components of guided waves, and accurately extract wave packet spikes of guided waves.