High-speed large dimensional measurement based on line structured light and camera scanning

The measurement of bulky forgings belongs to large size measurement under complex conditions. It needs high efficient and precision automatic non-contact measuring method in real time with high resolution. In this paper, an online measurement method is proposed based on single stripe structured light and liner camera scanning together. We choose liner CCD camera with excellent frequency response and high resolution. In addition, that camera and structured light scan forging's surface together driven by PTZs like painting grids enhances the resolution, so the details of features on forging edge can be obtained. A novel camera calibration method based on vector is developed. It only needs to calibrate the initial vector of optical axis instead of attitude matrix and principal point of camera based on three space points. The optical center of camera is measured and adjusted to close the center of rotation axis before calibrating and the vector of optical axis can be calculated using the pitching angle from photoelectric encoder on the PTZ after camera pitching, so those simplify the measurement process and avoid dynamic calibration. Through experiments manipulated in the laboratory verifying, the precision of the method can meet the demands, and the process is simple and suitable for measurement in forging factory.