Profile Measurement Techniques Of Small Parts Based On Parallel Beam Interference Projection

Optical shape measurement technology, which uses non-contact measurement method to obtain the outline information of the object surface, which has a wide application prospect in precision measurement. Fringe projection method has become a very active research area in the field of optical morphology measurement, which is a very active research field. Conventional grating projection can not take the high accuracy, strong adaptability, high speed fringe projection into account at the same time, digital projection can achieve adaptive, but the resolution limits it, it is difficult to produce high density sine fringes, the two projection techniques are not suitable for accurate measurement of small parts. Based on the theory of wavefront control and correction in adaptive optics, the modulation technique of wave front is introduced, and the dynamic adjustment of the space optical field of the interference fringe is realized by modulating the modulation of the interference fringes. The shape measurement of small parts is provided with a kind of fringe projection method which can obtain high spatial resolution and strong adaptability. The following technical problems in the measurement of small parts based on parallel beam interference projection are mainly studied:1) The knowledge of phase measurement and optical phased array is a deep learning. The mathematical model of the measurement system of the parallel beam interference projection is established, which is the theoretical basis for the recovery of the shape of the object.2) The parallel beam interference projection fringes can be determined by the optical phase control technique which can quickly change the phase of the coherent light wave, and can adjust the projected fringe patterns dynamically, which can improve the measurement efficiency. Focus on the relationship between the error of the wavefront phase modulation error of the electro-optic crystal and the distribution of the interference fringes. The imaging model of the optical crystal is established, and the relationship among the refractive index, the flatness and the wavefront modulation and the fringe imaging characteristics of the non ideal conditions is established.3) Optical phase control technology has high resolution, which can adjust the phase of the projection fringes accurately, which can improve the accuracy of the solution. The model of the accuracy of beam pointing accuracy of phased array control is established, and the error transfer relationship between beam direction and phase shift is analyzed, and the error is corrected.The design of the parallel beam interference projection system uses the optical phase control device as the angle of the beam angle adjustment mechanism. It can realize the adjustment of the spatial energy distribution of the interference fringes and the pure electronic control phase shift.