Research Stereo Measurement Technology

With the development of the technology and the manufacture, the three-dimensionalmeasurement on the surface of the object get more and more widely used in the field ofindustrial test, machinery manufacturing and reverse engineering and others, how toimprove the speed of measurement on the basis of maintaining high precisionmeasurement is the key to three-dimensional measurement.This paper presents a three-dimensional measurement based on sinusoidal gratingprojection, and study the current phase shift algorithms, the phase unwrapping problem isone of the focuses of phase shift measurement, mainly divided into the single frequencyphase shift and multiple frequency phase shift. Using multiple frequency phase shiftstripe can improve the accuracy of solution phase, but be reasonable choice the stripefrequency, too many stripes will affect the speed of the system measurement. Theparameters of the system calibration has been one of the key technology of3dmeasurement, the results of the calibration directly influenced the accuracy of the3d data.This paper presents a test method of calibration precision on the basis of the calibrationalgorithm based on halcon, through this testing method can effectively improve theefficiency of calibration, and better implementation of the image distortion correction.Finally, according to the theoretical analysis in this paper, established a singlecamera-projector measurement system, phase principal value is obtained by using thefour step phase-shift, the launch phase is obtained by multiple frequency heterodynealgorithm, according to the principle of triangle range to get a phase to the height of theconversion, then obtained the three-dimensional information of the object, the systemneed10seconds to complete a test,and measurement accuracy can achieve to0.2-0.8mm.