An Adaptive Projection Moiré Method for Continuous Surfaces

Abstract

An adaptive projection moiré method for a continuous surface, comprising: measuring the three-dimensional preliminary appearance of an object by projection moiré technology through a calibrated real projector and camera; internal parameters obtained according to the three-dimensional preliminary appearance and calibration and external parameters to construct a virtual projection moiré model, based on the preset ideal moiré parameters, simulate the grating pitch that meets the projection requirements in a virtual environment through an adaptive iterative algorithm and generate a numerical raster image to be projected; finally, the numerical value The raster image is projected onto the surface of the object to be measured by a real projector and the evenly distributed moiré image is collected to obtain the precise three-dimensional shape of the object to be measured. For any measured object with a continuous surface, the present invention generates corresponding non-uniform projection grid lines and ideal uniformly distributed adaptive moiré, thereby improving the measurement accuracy of the whole field and making the measurement error distribution of the whole field more uniform, It is suitable for high-precision and high-resolution measurement of objects with large curvature and has no additional requirements for hardware and low energy consumption during operation. It is suitable for on-site testing.

Description

technical field [0001] The invention relates to a technology in the field of optical measurement, in particular to an adaptive projection moiré method for continuous surfaces. Background technique [0002] As a full-field optical measurement method, the projection moiré method forms a moiré grating with a lower density than the original projected grating, so it can amplify the phase change of the grating caused by surface deformation, thereby achieving a higher Phase resolution and measurement accuracy. However, the distribution of this moiré pattern is extremely uneven, and its non-sinusoidal phase error will be introduced in the area where the grid lines are dense, and the phase noise is relatively large in the area where the grid lines are sparse. The above two kinds of phase errors will make the measurement error in this area larger, so the measurement accuracy distribution of the whole field is uneven. Contents of the invention [0003] The present invention aims at...

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Problems solved by technology

[0003] The present invention aims at the extremely irregular distribution of the moiré patterns generated by the existing scanning projection moiré technology within the full-field measurement range, and the measurement error in areas where the moiré is too sparse and dense is larger than that in uniformly distributed areas, that is, the full-field measurement For the defects of poor performance, an adaptive projection moiré method for continuous surfaces is proposed. For any measured object with a continuous surface, corresponding non-uniform projection grid lines and ideal uniformly distributed adaptive moiré are generated. In this way, the measurement accuracy of the entire field is improved, and the measurement error distribution of the entire field is more uniform. It is suitable for high-precision and high-resolution measurement of objects with large curvature. At the same time, there are no additional requirements for hardware and low energy consumption during operation. It is suitable for on-site testing.

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