Deformation And Strain Measurement And Its Application On The Blade Based On Machine Vision

As machine vision measurement with the advantages of high precision, noncontact, real-timeanalysis and control, etc, overcome the shortcomings of blades deformation measurement based onresistance strain gauge and maintain the original rodynamic shape of blades. So study the bladesdeformation based on machine vision measurement has important theoretical and practical values.Taking machine vision measurement of blades deformation for background,this paperresearch on monocular and binocular vision measurement based on mark points, and analysis theinfluence of camera resolution and camera field of view the on measurement accuracy: themeasurement accuracy is better with high camera resolution under same field; the measurementaccuracy is better with high camera focal length under same resolution. Research on monocularvision measurement based on digital image correlation,through the Harris corner detecting andmatching, which improved the initial value of Newton-Raphson,and improved the interpolationmethod., which increases the calculation efficiency and avoid the disadvantage that traditionalNewton-Raphson does not suit for the condition that the deformed image has a rotation angle. Withthe specific experiment, verify the measuring precision of monocular vision and binocular visionmeasurement, study on the influence of baseline and object distance on binocular vision accuracy:the precision is better with the baseline increases and the object distance decreases, the influence ofbaseline is lager than object distance, and compare the advantages and disadvantages betweenmonocular and binocular vision measurement.Test results showed that: the accuracy of the digitalimage correlation method was better than vision measurement based on mark points, and the digitalimage correlation method could measure the fullfield deformation and also with the disadvantageof experimental conditions, the operation and the picture quality. Finally measured the NACA0015type bending deformation and the dynamic deformation of fan blades, which provides a theoreticalguidance and experimental basis for the next step in the measurement of rotary blade deformation.