The Research Of 3D Small-field Imaging System Based On Fringe Projection Technique

The 3D(Three-dimensional) shape measurement for small objects is an important branch of the modern testing technique. The corresponding 3D shape measurement technique has been developed quickly since the MEMS(Micro Electro Mechanical Systems) devices were widely used abroad in the 1980 s. In general, the domestic test system for small objects also needs to be improved performance compared with the foreign test devices and test techniques. Therefore, the higher test accuracy, more automatic and higher test speed are the goals of the shape measurement techniques.Based on the above situation, this dissertation makes an intensive study of 3D shape measurement for small objects in theory and in practice. First, the development of 3D shape measurement for small objects is summarized, especially for MEMS device. Then the advantages, disadvantages and the scope of methods for measuring are analyzed. The dissertation chose the optical fringe projection to obtain the 3D shape for small objects because of the advantages of high-accuracy, non-contact, and fast acquisition. Next, the appropriate optical devices based on the size of the tested objects are selected to build a hardware system for obtaining the 3D shape of small objects. The field of view and deformation fringe patterns can be got by adjusting the optical route. Third, the software of calibrating and verifying the system has been developed. The design of a 3D small-field imaging system based on fringe projection technique is completed by combining the software and hardware system. Finally, experimental results on measuring 3D shape of small objects show the accuracy and availability of the developed 3D imaging system after the system is calibrated.