Target control point position calibration based on coordinate measuring machine and global bundling optimization algorithm.

The article focuses on a high-precision calibration method for control point positions in stereoscopic target-based coordinate measuring systems, which consist of a target, camera, and computer for spatial coordinate measurement. It proposes a global bundle optimization algorithm that calibrates all control points within the camera's field of view simultaneously, simplifying the process and improving efficiency compared to traditional individual point calibration methods. Simulation and experimental results demonstrate that the key factor affecting calibration accuracy is the motion range of the measured target within the imaging plane, not the number of measurement nodes, and that a control point stitching method enables accurate calibration of large targets despite limited coordinate measuring machine (CMM) motion range. The method achieves standard deviations of measurement precision of 0.01 mm in the x and y directions and 0.08 mm in the z direction, outperforming previous approaches in both accuracy and speed.