Calibration method for stereo vision sensor based on spatial points

A high-precision calibration method for stereo vision sensor based on random spatial points is presented.By giving 3D spatial point coordinates by a coordinate measurement machine(CMM) and corresponding image point coordinates,the calibration method is realized by taking the projection matrix elements as unknown quantities and using singular value decomposition to get the least-squares solutions,which avoids solving internal and external parameters of each camera and eliminates the calibration error caused by template machining and measurement.A group of random spatial points are measured by the calibrated stereo vision sensor,and measuring results show that,compared with CMM measurement values,the errors are less than 0.05 mm in the X axis direction,and less than 0.01 mm in the Y and Z axis direction,which indicates that the technique is feasible and effective.