应用数字散斑相关的运动轴面位置匹配

由于进行转轴动态扭矩测量时的旋转运动会导致应变测量无法直接进行,故提出了应用数字散斑相关技术的动态转轴表面位置匹配方法。该方法可通过对旋转运动中轴面位置的识别实现后续转轴表面应变位移的计算。搭建了运动轴面数字散斑相关实验系统,进行了轴面灰度值稳定转角范围的标定实验、标准转角的转角位移测量实验和运动轴面位置识别实验。实验表明,本系统轴表面图像在-π/15~π/15转角内灰度值较稳定,该转角范围对应转动方向160个像素,相关系数曲面有明显峰值,转角为-π/15和π/15的相关度分别为0.389 2和0.322 1,超出该范围后图像灰度信息淹没在由轴面弧度变化引起的噪声中;标准转角轴面位移识别精度和运动轴面位置识别精度为1像素。本文方法解决了旋转运动轴面的位置匹配这类大位移测量问题,为动态转轴的位移、应变等测量问题提供了有效方法。

Position matching of dynamic shaft surface based on digital speckle correlation

As the rotating movement in dynamic torque measurement will prevent the strain measurement directly, a position matching method for the dynamic shaft surface was proposed based on the digital image correlation method. The method recognizes the position of shaft surface in rotating movement to calculate its strain displacement. An digital image correlation experimental system for the movement shaft surface was set up, and a calibration experiment to determine the angle ranges of shaft surface with stable grey values, a measurement experiment of standard angle displacement, and an identification experiment for the position of dynamic shaft surface were set up, respectively. Experiments show that the grey value is stable when the angle range is -π/15-π/15, in which the obvious correlation peak has been extended to 160 pixels in the rotational direction. The relevance is respectively 0.389 2 and 0.322 1 when the angels are -π/15 and π/15. Out of which, the image gray gradation information is submerged in the noise caused by the changes of shaft radians. Moreover, both the precisions of standard rotation-deflection and dynamic position of the shaft surface are 1 pixel. The method solves the problem on position matching of the dynamic shaft surface and also provides an effective method for measuring the strain and displacement of the dynamic shaft.