Calibration technique of binocular vision measurementsystem using light pen

Aiming at the calibration problem of the binocular vision measurement system using a light pen, the theory about the calibration of camera intrinsic parameters, double-camera extrinsic parameters and measuring pen was discussed. At the same time, the whole calibration system based on LabVIEW was developed. The camera intrinsic parameters calibration wasachieved by using Zhang plane calibration method,while the double-camera extrinsic parameters calibration was achieved by the method based on standard length. Using the method combining the particle swarm optimization with the Levenberg-Marquard(LM) algorithm, the high-dimensional optimization target function was speeded up effectively. In the process of measuring pen calibration, a very convenient field calibration method based on least square was proposed. The calibration system could complete all the preparation work before the relevant measurement. It has high precision and practicability. Based on the calibration results of measurement system, the standard deviation of test result for the 25 mm diameter standard ceramic ball is 0.019 mm.