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

提出了一种高速、高精度的形状和变形测量方法——集成移相法。在本研究中，我们对该方法进行了进一步的发展，提出了一种针对大型结构和连续运动物体的缺陷检测方法。我们的成果如下：●我们使得使用线性传感器获得云纹条纹成为可能，而不需要特殊的图像处理，它显示物体的轮廓线，基于扫描云纹方法的相同原理。●采用该方法对某混凝土墙体进行了实测，验证了其有效性。●研究了用光栅投影法测量大型结构的方法。提出了一种包含线性传感器捕获线的平面内投影方法。利用这种方法，我们研制了移相光学系统。我们还研究了一种有效投影光栅的方法，开发了在平面上投影均匀光栅的光栅投影方法。●研制了平行光光栅投影系统、测量实验装置和形状测量软件。我们整合了这些发展并进行了形状测量实验。为了提高测量精度，我们提出了一种基于多个参考平面的每像素校准方法。形状测量实验结果表明，该系统可实现分辨率小于1 mm的连续物体的形状测量。●在光栅图样强度分布不够精确的情况下，采用多平面测量可以提高测量精度。●通过计算验证，即使列车以300公里/小时的速度行驶，采用高亮度光源也能实现1毫米以下分辨率的形状测量。

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.