基于双目立体视觉与数字散斑图像相关的全场振动测量

Full-field vibration measurement based on binocular stereo vision and digital speckle image correlation

研究了基于三维数字散斑图像相关方法(3D-DSCM)的三维全场振动测量相关问题。该方法通过双目高速摄像机连续采集散斑动态变形图像,结合数字散斑相关方法对目标点进行相关匹配,可得到随时间变化的物体离面振动位移信息。通过正弦激励稳态响应的比对实验、各参数(相关函数、子区大小、形函数)选择对测量结果的影响的实验研究。研究结果表明50 Hz稳态激励下的所测振动幅值相对误差小于3.5%、幅频曲线相关系数高于98%;相关函数、子区大小、形函数的选择都对计算的精度具有很大的影响。

The three dimensional full-field vibration measurement-related problems were studied based on the 3D digital speckle correlation method （3D-DSCM）. With this method, binocular high-speed cameras were used to continuously collect speckle dynamic deformation images and match target points combining with the digital speckle correlation method.The out-of-plane vibration displacement information of a body varying with time were obtained.Here, through comparative tests of the steady-state responses of the body to sine excitations,the effects of parameters including correlation function,area size and shape function on measurement results were studied.The results showed that the relative error of the vibration amplitude measured under the steady excitions of 50Hz is less than 3.5%,the amplitude-frequency curve correlation coefficient is higher than 98%;correlation function,area size,and shape functions have a great influence on the accuracy of calculation.