Larg-scale 3D coordinate measurement based on orthogonal cylindrical imaging cameras

A larg-scale 3D coordinate measurement method based on orthogonal cylindrical imaging cameras was proposed. The camera was consisted of one orthogonal cylindrical imaging system and two orthogonal linear CCDs, which were used to detect the horizontal angle and vertical angle of a measurement point, respectively. One camera determined two angles, therefore, the 3D coordinate of the measurement point can be measured by the intersection of two cameras. The proposed method has prominent advantages in precise coordinate measurement and especially in dynamic positio-tracking. A flexible intrinsic parameters calibration method was used to calibrate the orthogonal cylindrical imaging cameras. After intrinsic parameters calibration, the average of angle measurement error in the horizontal and vertical direction of the camera is 1.85 and 2.16, respectively. In addition, the extrinsic parameters calibration of the two cameras is also introduced. After extrinsic parameters calibration, the coordinate measurement accuracy of the system is better than 0.52 mm. The experimental results show that the proposed 3D coordinate measurement method is valid with good measurement accuracy.