3D localization of a labeled target by means of a stereo vision configuration with subvoxel resolution

We present a method for the visual measurement of the 3D position and orientation of a moving target. Three dimensional sensing is based on stereo vision while high resolution results from a pseudo-periodic pattern (PPP) fixed onto the target. The PPP is suited for optimizing image processing that is based on phase computations. We describe experimental setup, image processing and system calibration. Resolutions reported are in the micrometer range for target position (x,y,z) and of 5:3x10(-4) rad: for target orientation (θx,θy,θz). These performances have to be appreciated with respect to the vision system used. The latter makes that every image pixel corresponds to an actual distance of 0:3x0:3 mm2 on the target while the PPP is made of elementary dots of 1 mm with a period of 2 mm. Target tilts as large as π=4 are allowed with respect to the Z axis of the system.