A Real-time Object Volume Measurement Method Based on Line Laser Scanning

Abstract

Volume measurement of objects has numerous applications in industry and transportation, especially non-contact volume measurement is required in many scenarios. Laser scanning technology is widely used in non-contact volume measurement, but the current volume measurement methods based on laser scanning usually treat the point cloud of the object as a whole structure, which leads to the inability to measure the volume in real-time and the increase of measurement error. Based on the above, we designed a real-time object volume measurement system based on line laser scanning. The principle is: After irradiating the object with a beam of line laser, it will form an undulating curve according to the shape of the surface of the object, and then a single frame image can be obtained by shooting from the side with an industrial camera. The frame image is processed by the Rosenfeld image thinning algorithm of fusion burr trimming to obtain the contour lines of the object. And then the outline is processed into a line of outline points by the mapping of the 2D image to the 3D space. Multiple lines of outline points can be obtained during the movement of the object, splicing it to obtain a point cloud that can represent the surface of the object. Since the ordered point cloud obtained by the above method naturally has the condition of integration by the differential method, the volume of the object is calculated in the process of obtaining the ordered point cloud in a point-by-point, line-by-line integration way, which achieves the effect of calculating the volume of the object in real-time during the scanning process.