【摘要】 为了实现高压水射流冲击不同材质和几何尺寸靶物时的反射声音信号特征值的有效提取,应用小波降噪法和模极大值算法实现对反射声信号进行处理。采用传声器和NI公司的PCI6251采集卡搭建高速数据采集设备,实现反射声信号的高精度实时采集,应用Matlab编制小波降噪和模极大值提取反射靶物材质和几何尺寸反射声特征值程序,通过调用Mathscript节点实现所采集的信号在LabVIEW与Matlab中通讯,完成信号的降噪和有用信号的分离与提取,实验的结果验证了所建立的信号采集与处理系统能实现实时提取对应不同靶物材质及几何参数的特征值。利用模极大值算法和数据库技术最终完成对靶物材料及几何形状的在线识别。更多还原

【Abstract】 In order to extract the eigenvalue of the reflective sound signal produced when the targets having different material and geometry ware attacked by high pressure water-jet effectively,the reflective sound signal was processed by using wavelet noise reduction and wavelet modulus maximum algorithm.High-speed data acquisition equipment was built by using microphone and and NI PCI6251 data acquisition device which realize the accurate and real-time data acquisition.The reflective sound signal eigenvalue extraction software by using wavelet noise reduction and wavelet modulus maximum algorithm was programmed by adopting Matlab.The signal communication between LabVIEW and Matlab was realized by calling Math script node,The signal denoise and the useful signal separation can be accomplished by the software.The experiment results verified that the built signal acquisition and processing system can realize the real-time eigenvalue extracting.By building modulus maximum algorithm method and matching eigenvalue data base,the system can complete identification of material and geometry of eigenvalue.更多还原