Measurement of Large-Sized-Pipe Diameter Based on Stereo Vision

Abstract

To address the lack of fast and high-precision in situ measurement of large-sized pipes in current industrial applications, a pipe-diameter-measurement method based on stereo vision is designed in this paper. By using multiple sets of binocular cameras to perform 3D reconstruction and integration of multiple laser markers projected on measured cross sections of pipes, the pipe diameter can be estimated. In this method, a measurement algorithm is adopted to enable automatic matching of feature points through affine distance transformation, and an optimized point-cloud-registration algorithm with normal-vector constraints is used to ensure measurement robustness. To verify the feasibility of the method, an experimental system was built under laboratory conditions, and three types of pipes with outer diameters from 285 mm to 325 mm were measured. The experimental results show that the relative error is within ±0.570% and the maximum repeatability standard deviation is 0.551 mm. The experimental results basically meet industrial standards, and the proposed method therefore has good application prospects.

Accuracy improvement of a multi-ring beam structured inner surface measurement: via novel calibration methodology and light source optimization

“…surface measurements of these parts are becoming increasingly crucial. Recently, researchers have conducted extensive related studies and developed reliable commercial measurement instruments [4][5][6][7][8]. These instruments are divided into two main types, contact and non-contact, based on their measurement mechanisms.…”