Health Monitoring for Large Structure by Shape and Defect Inspection Method Using Phase Analysis of Linear Sensor

点击翻译按钮获取中文摘要

We had developed a high-speed and high-accuracy shape and deformation measurement method using Integrated Phase-shifting Method. In this study, we made further development to this method to propose a defect inspection method for the large structure and the continuously moving object. Our achievements are as shown below.●We made it possible to use the linear sensor to obtain moire fringes without special image processing, which show the contour lines of an object based on the same principle of the scanning moire method.●We measured an concrete wall with the proposed method and confirmed its efficiency.●We made a study of the grating projection method to measure the large structure. We proposed a method of in-plane projecting including the capture line of the linear sensor. Using this method, we developed the phase-shifting optical system. We also studied for a method to project the grating efficiently and developed the method of grating projection that projects uniform gratings on the plane.●We developed the grating projection system with parallel light, the measurement experimental setup and the shape measurement software. We integrated those developments and conducted shape measurement experiments.●To measure more accurately, we proposed a method of every pixel calibration with multiple reference planes. The result of our shape measurement experiment proved that shape measurement of the continuous object with the resolution of 1 mm or less is realized with this system.●We confirmed that measurement accuracy can be improved by using multiple planes even though the intensity distribution of the grating pattern is not accurate enough.●We verified that the proposed method realized the shape measurement with the resolution of 1 mm or less computationally by using the light source with high brightness even if it is conducted by the running train at 300 km/hr.