设计了一个基于模态分析技术的嵌入式索力检测系统.其选择使用具有较好性能及计算精度的特征系统实现算法识别拉索的各阶模态频率,并利用基于频域平滑的重采样技术和随机减量技术对振动信号预处理以得到自由响应信号;基于ARM芯片和Linux平台,使用嵌入式J2SE技术开发实现了监测系统,并进行了实际工程应用测试.结果表明:在嵌入式系统中实现的预处理算法和特征系统实现算法能够较精确地识别出大多数情况下拉索振动信号的基频值,并据此计算出索力值,设计的嵌入式索力检测系统具有有效性和实用性.
An embedded cable force detection system based on the modal analysis technology is designed in this paper. In view of the characteristics of the embedded system, we select the ERA owing to its better performance and computational accuracy to identify the modal harmonic frequency of cable, and obtain the free response signal using the random decrement technique to preprocess the vibration signal. The detection system is engineered on the basis of the ARM9 chips, Linux operating system and embedded J2SE technology development. The test results from the field engineering measurement show that the improved random decrement technique and ERA implemented on the designated embedded system can quickly identify base frequency of most cable vibration signal from which the cable force values can be calculated for. The proposed approach has demonstrated the efficiency and practicability of embedded cable force detection system based on modal analysis techniques.