A universal, rapid and accurate measurement for bend tubes based on multi-view vision

Non-circular-cross-section tubes are widely used as heat exchange components throughout the industry, including in fields such as aerospace, automobiles, and vessels. Tube manufacturing in these fields is a highly complex process; to manufacture the needed tubes and guarantee a precise and stress-free assembly, the geometric parameters should be measured during manufacturing and before assembly. However, current studies and manufacturing instrumentation focus on tubes of circular cross section. This study proposes an extraction method for the tubular 3D skeleton of non-circular-cross-section tubes based on multi-view vision. Then, non-circular-cross-section tubes can be measured based on the proposed method. The experimental results show that the average deviation does not exceed 0.3 mm with 3\sigma reliability and the measuring time is fewer than 5 s. The accuracy and efficiency of this method are sufficient to satisfy the requirements for industrial applications.