Abstract:Aiming at 3D laser scanning to achieve irregular raw meat contour imaging, there are problems such as incomplete scanning contours, missing data, and low volume estimation accuracy. In light of these limitations, a 3D visual imaging system was presented based on the contour shaping unit. This system was designed to address the morphological characteristics of irregular raw meat, with the aim of optimizing the imaging performance of irregular raw meat. The operational methodology of the contour shaping apparatus was delineated, and the essential hardware modules, including the sample driving and transmission unit, scanning external trigger control unit, and imaging detection platform. Additionally, the relationship between the rotational orientation of the hinge bolt in the shaping apparatus, the number of motor rotations, and the desired contour angle of the raw material meat was determined. A 3D visualization software was ultimately developed on the Halcon platform by utilizing the C# language. The point cloud processing model reconstruction algorithm and gray dilation hole compensation algorithm were employed to facilitate the acquisition of information, analysis of data, and comparison of volume estimation accuracy before and after contour shaping of irregular raw meat. This was done in order to validate contour shaping to optimize the imaging performance of meat. A total of 120 pieces of chilled and frozen pork（hind shank and loin） was employed to substantiate the enhanced functionality of the shaping unit for the imaging of raw meat contours. The results demonstrated that the post-scanning imaging accuracies of the meat pieces at 90 °, 180 °, 270 ° and360 ° relative to the transmission direction were greater than 90%, and the coefficients of variation were no more than 3%. The optimal angle for shaping ranged from 30 ° to 50 ° for chilled meat and from 40 ° to 60 ° for frozen meat. The accuracy of volume estimation was improved from 90% to over 94%, and 97%, respectively. Following the shaping process, the contour of chilled and frozen meat morphology can be maintained for over 6 s, with a maximum compression ratio of hole height below 0.77. The research result demonstrated that the imaging performance of irregular raw meat can be significantly enhanced through the application of a contour shaping unit. This finding provided a valuable foundation for subsequent research and development efforts aimed at advancing quantitative slitting technology based on contour imaging for irregular raw meat.
