Development of High-Speed-Scanning, Three-dimensional Mapping System

开发了高速扫描三维测绘系统，该系统可以对腐蚀损伤面和断裂面进行空间和远程测量。该系统基于激光光的像散聚焦误差信号法，该方法已应用于磁光盘系统的焦伺服系统中。新设计的光学系统是为了测量更大范围的170 μ m腐蚀损坏表面，并进行了改进，以补偿试样的反射率变化，并消除干扰光，如荧光灯。测量了腐蚀坑、腐蚀疲劳腐蚀损伤面、空气中循环应力腐蚀开裂和疲劳的断口面、腐蚀磨损面等三维形貌；该系统能够精确测量宽区域（25毫米）的三维形状，包括具有突然高度变化的表面，如腐蚀坑。

The high-speed-scanning, three-dimensional mapping system has been developped, which can spatially and remotely measure the surface topographies including corrosion damaged surfaces and fracture surfaces. The system is based upon the astigmatic focus error signal method using laser lights, which has been already applied to the focal servo system in magnetooptical disk systems.The optical system was newly designed in order to measure a wider range of 170 mu m for corrosion damaged surfaces, and was improved to compensate the reflectivity changes of specimens and to remove disturbing lights from such as fluorescent lamps. The three-dimensional shapes, including corrosion pits, corrosion damaged surfaces in corrosion fatigue, fracture surfaces of both cyclic stress corrosion cracking and fatigue in air, and the surface of corrosive wear were measured; the system is able to measure precisely the wide areas ( 25 mm) of three-dimensional shapes, including surfaces which have sudden height changes such as corrosion pits.