利用数字图像边缘检测识别梁的模态参数

摘要

基于数字图像边缘检测技术,对附集中质量的某梁模型进行振动测试,以普通数码摄像头与PC机作为视频采集设备,实时获取梁的振动图像,运用三次多项式拟合实现边缘的亚像素定位,以获取梁振动的位移时程曲线,后处理采用模态分析识别梁的模态参数,试验表明采用该方法进行低频结构的模态试验是可行的.%Based on digital image edge detection technology, the vibration testing of the simply supported beam model suspended with concentrated masses is identified in this paper,the real-time vibration images of beam is obtained by the general digital camera and PC as its hardware, meanwhile, uses cubic polynomial to fit the edges to realize sub-pixel localization, displacement-time curve of beam with vibration is obtained. In the post-processing,the modal parameter of simply supported beam model is identified by the modal analysis. The testing results show that achieving the modal test of low-frequency structures by the method of this testing system is feasible.