Three-dimensional Angular Measurement Based On Moiré Fringe And Auto-collimation

While AT&T ship is sailing on the sea, the deformation of hull can be cause byvarious kinds of factors, which can influence measuring accuracy, so the deformationshould be measured and fixed.This paper is focused on the measuring methods based on moiréfringes andself-collimation three-dimension angle measurement. The pitch and yaw angles androll angles can be indicated by the inclined plane and the edge of a right-angle prismrespectively. The pitch and yaw angles can be measured by the method ofself-collimation, and the roll angles can be measured by moiré fringes. Thetheoretical model of measurement is set up, and the measuring range, resolution andaccuracy are analyzed, especially the influence of pitch and yaw angles onmeasuring roll angles.Based on the theoretical analysis, we design a three-dimension deformationmeasurement system, particularly the design of optical system, mechanical systemand LED drive. In view of the designing results, we complete the alignment and getpictures of reticule and moiréfringes, besides the processing algorithms of reticuleand moiréfringes are studied.Finally, the static and dynamic experiments are conducted under laboratoryconditions. The experimental results show that: the RMS of static measurement accuracy within close range(2m) is less than5″,and the RMS of dynamicmeasurement accuracy is less than10″.As a result, the measuring method is verified.