基于图像边缘识别的面内振动位移测试方法

In⁃Plane Vibration Measurement Technique Based on Image Edge Recognition Method

为降低传统测试系统的复杂度并减小其对被测结构的附加质量影响,提出了一种以视频图像作为测试信号的振动测试方法,建立了被测物体位移与图像边缘识别结果的对应关系。由于在经典的图像边缘处理中,不连续边缘和虚假边缘会对处理结果有一定的影响,利用数据拟合的方法对图像边缘处理方法进行了改进,从而使测试结果更加精确。为验证该测试方法的有效性,设计了实验验证系统。实验结果表明,改进的边缘处理方法相比于原有的方法,得到了目标物体更精确的边缘,其位移计算精度提高了12%,且在0~60 Hz的测试频段内,准确地得到了目标物体振动的大小和方向。所提出的测试方法具有测试系统简单、测试范围灵活及测试结果丰富等优点,可为有限测试环境下的振动测试提供一种新的思路。

This paper presents an in-plane vibration measurement technique to reduce the complexity of traditional vibration test system and eliminate its added mass influence on the measured structure.The corresponding relations between the displacement and the image edge recognition result of the measured structure are established.Because of the influence of discontinuous edges and false edges obtained by the traditional image edge recognition method on the test results,a data fitting method is adopted and the traditional image edge recognition method is improved,which make the testing results more accurate.Moreover,to verify the effectiveness of the proposed test method,a vibration test system is set up and corresponding typical experiments are carried out.Results show that a more precise edge of object is obtained by the proposed improved method compared with the traditional method.The precision of displacement calculation with the proposed improved approach is 12%higher than that with the traditional approach.Furthermore,both the vibration magnitude and direction of target object are captured precisely within the test frequency band of 0~60 Hz.It can be concluded that the in-plane vibration testing system proposed in this paper has the advantages of simple set-up,flexible frequency range and sufficient test data,and it is promising in finding an alternative method with limited testing conditions.