Research On Calibration Technology Of Hand-held Visual Sensor

Nowadays handheld vision measurement is applied in the automobile manufacturing,aerospace science and technology manufacturing industry widely. In order to overcome the shortcomings of the calibration of line structured light vision measuring systems, such as the difficulties in the field calibration, calibration accuracy, etc. In this paper, based on the experimental platform of the handheld vision measurement system, the calibration technology of the binocular stereo vision sensor and a hand-held vision sensor is studied, and the reliability of the results is verified by experiments.The hand-held vision measuring system is composed of a binocular visual tracker and a hand-held line structured light sensor. In the measurement process, the local 3D world coordinates of the hand-held sensor are transferred to the world coordinate system by means of feature points and binocular vision. The center of the circular marker point is extracted by gray centroid method, on this basis, the center of the laser stripe is extracted from the direction template. A calibration method for binocular vision tracker based on one dimensional standard rod is proposed, firstly, the fire hidden point properties and cross ratio invariance are used to complete calibration of optical center and distortion, after using the epipolar geometry and the Kruppa equations to complete the other parameters of the camera calibration, finally, all the parameters are optimized by bundle adjustment. For hand-held vision sensor, the calibration method based on planar template, the world coordinates of the target points on the light plane are obtained by known feature points on planar template and cross ratio, then, the light plane equation is optimized by iteration.