Research On Shadow Moire Measuring Device And Its Adjustment Technology

Optical 3D sensing is widely used in the measurement field due to a series of advantages of non-contact and high resolution.With the improvement of measurement requirements,the traditional phase-shift shadow Moiré profilometry has been unable to meet the needs of high-speed and high-precision measurement in modern manufacturing process due to its high requirements on phase-shift accuracy,cumbersome calibration process and inflexible application.Therefore,it is of great practical and theoretical value to establish a rapid moire measurement method.In this paper,the phase shifting shadow Moire method is studied in depth,and the following tasks are mainly accomplished:(1)The paper analyzes the relationship between the key parameters of shadow moire measurement structure and the contrast of stripes and measurement errors,designs reasonable structural parameters,including the selection of camera,grating and the determination of the position relationship among the parts,and builds the platform of measurement system.The control program of data acquisition system is programmed by Lab VIEW,and the friendly interface in Windows environment is developed to realize the integrated control of the module such as image acquisition,component control,CCD parameter setting,etc.(2)Analyse the relationship between phase shift and measurement sensitivity,and propose a real-time measurement sensitivity calibration technique based on three-frame fringe pattern,which realizes the rapid calibration of measurement sensitivity and realizes the high-precision positioning of measurement system parameters.(3)A three-frame self-calibration phase shadowed Moiré three-dimensional profilometry based on Cramer's regularization is proposed in this paper.This method and the classical GS method are simulated by MATLB.The results of simulation and demodulation show that thetwo methods are equivalent,and the correctness of the proposed method is demonstrated theoretically.Using the five-step Harlharan algorithm as a reference,different algorithms are used to measure the surface of the same object.The results show that compared with the typical three-step phase shift method and principal component analysis method,the proposed method has the smallest phase error and simplifies the measurement process.(4)A two-phase phase shift extraction algorithm based on arc tangent function is developed.Compared with several typical algorithms,the simulation results show that the proposed method is insensitive to non-sinusoidal fringe pattern due to the use of the arc tangent function to solve the phase shift.It has the characteristics of reliable solution and easy application.The fast Moire measurement method established in this paper not only achieves the integrated control of multi-module in phase-shift shadow Moire measurement and the high-precision positioning of its system parameters,but also effectively solves the problem that the existing phase-shift phase extraction technique is limited in height measurement and the existing random phase-shift extraction algorithm has unstable calculation for non sinusoidal fringe pattern.