目视检查是最广泛使用的检查与发现结构部件、机构和零件缺陷的方法之一。但是，要检查内联结构中难以看到的部件就必须拆卸或分解有关的部件。而在某些情况下不损坏结构是不可能做到的（例如，风缸和管道）。为了扩大目视检查的可能性，在世界各国的实践中正在使用刚性或柔性 Visual inspection is one of the most widely used methods for inspecting and finding structural parts, bodies and parts defects. However, it is necessary to disassemble or disassemble the relevant components in order to check the inaccessible components in the inline structure. In some cases it is not possible to damage the structure (for example, a cylinder and a pipe). In order to expand the possibilities of visual inspection, rigidity or flexibility is being used in the practice of various countries in the world