3D displacement distribution measurement using sampling Moire method with multiple cameras

Abstract

A sampling moire method is useful to measure deformations of a large structure such as a building and a bridge. The sampling moire method can analyze 3D displacement using two cameras. The sensitivity of the displacement measurement for the z-direction is lower than the displacement measurement in the x-and the v-directions in this method because the cameras are placed near the direction of the z-axis against the object in general. However, the measurement noise level can be decreased with increasing the number of cameras. In this paper, the principle and the calibration method to measure 3D displacement using the sampling moire method with multiple cameras are shown. As the application, 3D displacement distribution measurement of a cantilever using the sampling moire method with multiple cameras is performed. The accuracy of the 3D displacement measured with using three cameras is compared to the displacement of the cantilever.