条纹投影非线性误差主动编码最优估计校正方法

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关键词：非线性校正；条纹投影;最优值估计;相位质量;结构光测量中图分类号：TH741 文献标志码：A doi：10.37188/CO.2024-0167 CSTR：32171.14.CO.2024-0167

Abstract： Stripe projection technology is widely used in 3D measurement and surface morphology reconstruction， where phase quality is a critical determinant of measurement accuracy. However， the nonlinear relationship between input and output light intensity is a major source of phase error.To address this issue， this paper introduces a novel system nonlinear active correction method. This method captures the variation pattern between input and output light intensity by projecting a smal number of uniform gray-scale images onto a standard plane. This pattrn is then integrated with active system nonlinear correction to construct a system nonlinear model based on the input-output light intensity variation. Genetic algorithms are used to optimize the coding values， which are then used to actively correct the projected fringes via fringe coding.The corrected fringes eectively reduce the influence of nonlinear effects， thereby significantly improving the quality of phase acquisition. To validate the proposed method，computer simulations were performed using three-step phase shifting. The results showed an 88% reduction in the standard error and an 85.5% reduction in the maximum error. In actual standard plane experiments， the corrected standard phase error decreased from 0.0706 rad to 0.0168 rad，and the maximum phase error decreased from 0.4129 rad to 0.0960 rad. In the face plaster model experiments，the corrected standard phase error decreased from 0.0472 rad to 0.0102 rad， and the maximum phase error decreased from 0.2990 rad to 0.240 8 rad. In 3D reconstruction of complex morphology plaster models of human faces， the surface quality was significantly improved，and the water ripple effect， which aects the phase quality， was significantly reduced. Compared with existing large-step phaseshifting methods，the proposed method not only achieves high phase acquisition accuracy，but also offers significant advantages in terms of required data volume and operational convenience， demonstrating broad application potential.

Key words： nonlinear correction; fringe projection; optimal value estimation; phase quality; structured light measurement

1引言

条纹投影轮廓术是一种非接触式三维测量技术，广泛应用于工业检测、质量控制、医学成像等领域。（剩余12175字）