撮像シミュレーションによる画像相関法の測定誤差発生メカニズムの解明

抄録

　　　Effects of relative positions of the random pattern and the imaging sensor for measurement error in digital image correlation method are investigated. In order to take account of the effect of the relative position of microlens array on the imaging sensor and the speckle image formed on the image plane, simulations of imaging processes are carried out. Errors of DIC measurement are evaluated using the simulated images having several displacements and initial gap between the center of the pixel and the speckle. As a result, relationships between the error and the displacements for each center gap show various profiles. The average profile of them shows a sinusoidal curve with a relatively low amplitude. Since various error profiles of each speckle in the random pattern are averaged in the subset area in DIC measurement of translation displacements, the error profile of the subset approaches the average sinusoidal curve.