Novel calibration method for a multi-sensor visual measurement system based on structured light

We focus on two key problems in the calibration of multi-sensor visual measurement systems based on structured light: the calibration of the structured light vision sensor, and the global calibration of multiple vision sensors. In the calibration of the vision sensor, the light-plane equation is computed by combining the Plucker matrices of light stripes obtained at different target positions. Since the light-plane equation is optimized by using all the light-stripe center points, the robustness and accuracy of calibration are considerably improved. For the global calibration of multiple vision sensors, the relative positions of the two vision sensors with non-overlapping fields of view are calibrated by means of two planar targets (fixed together), using the constraint that the relative positions of the two targets are invariable. The mutual transformations between the two targets need not be known. Using one of the vision sensors as the base vision sensor, the global calibration of multiple vision sensors is achieved by calibrating each of the other vision sensors with the base vision sensor. The proposed method has already been successfully applied in practic.