Technical Research On Three-Dimensional Measurement System Of Phase-shifting Fringe

Phase shifting fringe projection technology is a structured light non-contact measurement technology,which has wide application and excellent prospects in production and life.Despite years of development,there are still some problems with the existing phase-biased grating technology,which limits its development and application.Based on the digital phase-shifted grating projection technology,this paper studies some problems in phase shifting fringe projection technology and proposes feasible solutions.For the phase unwrapping algorithm,this paper proposes a spatial phase unwrapping algorithm that does not constrain the phase unwrapping path.It can complete the phase unwrapping faster while avoiding the propagation of noise in the wrapped phase map.The algorithm classifies the pixels of the wrapped phase map,and uses the detected edge pixels to partition the wrapped phase map.After assigning superimposed phase values to each area,different phase unwrap strategies are used to complete the phase expansion for different types of pixels.Simulation experiments and real experiments prove the effectiveness of the algorithm and its performance in practical applications,which is comparable to the quality of phase unwrapping of conventional algorithms.For the non-sinusoidal error of color composite phase shifting fringe projection technology,an error compensation method is proposed.This paper analyzes the mechanism of non-sinusoidal error in color composite phase shifting fringe projection technology,and introduces common compensation schemes.The method proposed in this paper generates a phase error look-up table(LUT)by collecting phase value samples on the plane background part of the wrapped phase map and matching them with the corresponding phase values of the ideal plane.And then,using this look-up table to directly compensate the measured wrapped phase map.Experiments verify that the look-up table created using the phase value is simple and practical,and the look-up table established using the gray value is more effective for error compensation.Aiming at the needs of the small field of view measurement in the follow-up research,this paper designs an optical system based on double cemented lenses.Calculate the initial structure of the optical system according to the design needs,and consider the characteristics of the initial structure for optimization.The optimized optical system parameters shown show that the designed optical system can meet the requirements of use.