Structural Design and Uncertainty Analysis of Coded Structured Light System for High-accuracy Shape Reconstruction

In order to explore measuring accuracy of coded-structured-light 3D measurement system onto high reflectance surface of turbine blade, measuring error analysis, system parameter design and uncertainty evaluation were investigated. First, device parameters and azimuth parameters of analytic geometry model and projective geometry model of coded structured light system were analyzed and unified. Second, based on analytic geometry model, quantization relationship between measuring error and device parameters, azimuth parameters were analyzed. Third, system parameters were designed by taking into account system range, shelter, depth of field, luminous power and system capacity. Finally, type B uncertainty evaluation based on error sources and transfer coefficients was done. Experimental results indicate that error of measured high reflectance unicolor standard plane is 0.60.8mm; reconstructed turbine blade shape has same visual effect as the real one; and type A uncertainty evaluation based on measured data on standard plane has similar result as type B. It can basically meet the requirements of turbine blade reconstruction in industrial site.