Research on Geometric Measurement Technology of the Inner Cavity of Cylindrical Parts

In this article, a cone-shaped structured light measurement method based on the principle of laser triangulation is proposed for the 3-D measurement of inner walls. Compared with existing measurement methods, this method avoids the risk of collision during conventional penetration measurement and has the advantages of high-efficiency and high-precision measurement. The laser is installed on the same side of the camera, which is easier to integrate into the probe and easy to install with the displacement table or mechanical arm. However, the method of installation will also reduce the overall measurement accuracy of the system because the local effective baseline distance in the conical structured light system is too short. For this reason, this article is aimed at improving the accuracy of the denoising algorithm, structure optimization, and calibration. To address the problem of the poor signal-to-noise ratio caused by the method of installation, the optical path design and image processing are processed accordingly. The test results of different caliber ring gauges indicate that our method achieves better stability and accuracy than existing measurement methods.