Incorporating defects and moisture in MOE evaluation for automated timber grading

In today’s industrial landscape, automated timber structural grading plays a pivotal role in optimizing productivity and operational efficiency. The anisotropic nature of wood renders standard visual grading a challenging task, often resulting in a grading process with low repeatability. Moreover, traditional grading methods are not only time-consuming but also susceptible to human bias and inconsistencies, which may lead to underestimation of the timber’s mechanical potential. To address these challenges, this study proposes a grading method that integrates external quality evaluation of timber and the internal elastic modulus properties. Additionally, an automated production line is developed featuring automatic loading and unloading, machine vision optimized sorting, online moisture content detection, mechanical stress grading, multi-sensor data integration, and remote operation and maintenance diagnostic functions. The developed intelligent automated grading system included five sections, including Automatic loading and unloading, Machine vision, Moisture content detection, Mechanical stress grading, and multi-sensor data coupling and remote O&M diagnosis. The novelty of this study included integrating the influences of multiple factors such as defects and moisture content, as well as their dynamic modulus of elasticity in the grading operations of structural timber. The methodologies employed not only promoted broader adoption and deeper understanding of automation in the wood processing industry but also positioned themselves as exemplary applications of advanced automation technology. The practical applicability of automated grading technology in industrial production lines was thoroughly validated. Experimental outcomes unequivocally demonstrated that the automated solution markedly enhanced grading efficiency while concomitantly reducing labor costs. This automated structural timber grading line was successfully certified by the Japanese JAS (Japanese Agricultural Standard) in 2023, which is the highest level of certification for organic agricultural products by the Ministry of Agriculture, Forestry, and Fisheries of Japan. This ensures that the graded structural timber exported to Japan meets the Japanese Agricultural Standards. By incorporating advanced automation technology, this grading process section can be flexibly integrated into automated wood processing production lines. This advancement anticipated the realization of intelligent and automated production line management, thereby providing robust technical underpinnings for the transformation and upgrading of the wood manufacturing industry.