Reduction of systematic errors in structured light metrology at discontinuities in surface reflectivity
Huimin Yue
Harshana G. Dantanarayana
Yuxiang Wu
Jonathan Huntley
2134/34323
https://repository.lboro.ac.uk/articles/journal_contribution/Reduction_of_systematic_errors_in_structured_light_metrology_at_discontinuities_in_surface_reflectivity/9548204
In measuring 3D shape with structured light techniques, systematic errors arise in the
neighbourhood of discontinuities in reflectivity or geometry. A mechanism for this phenomenon is proposed, based on the finite size of the imaging system’s point spread function. A theoretical analysis for the phase errors in a phase-shifting projected fringe system is given, from which a correction algorithm to minimise the systematic errors is presented. In this algorithm, a closed form expression for the errors based on the intensity values and the phase values in a neighbourhood excluding the affected region is used to remove the estimated error from the measured phase values within the affected region. Experiments on samples with both linear and circular discontinuities in reflectivity
demonstrated respective reductions in systematic errors by factors of 2.5× and 3×.
2018-08-06 13:24:32
Projected fringes
Profilometry
Edge detection
Systematic errors
Point spread function
Mechanical Engineering not elsewhere classified