In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper prop...In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper proposes an E-TPU midsole surface defect detection method based on machine vision to achieve automatic detection and defect classification. The proposed method is divided into three parts: image preprocessing, block defect detection, and linear defect detection. Image preprocessing uses RGB three channel self-inspection to identify scorch and color pollution. Block defect detection uses superpixel segmentation and background prior mining to determine holes, impurities, and dirt. Linear defect detection uses Gabor filter and Hough transform to detect indentation and convex marks. After image preprocessing, block defect detection and linear defect detection are simultaneously performed by parallel computing. The false positive rate (FPR) of the proposed method in this paper is 8.3%, the false negatives rate (FNR) of the hole is 4.7%, the FNR of indentation is 2.1%, and the running time does not exceed 1.6 s. The test results show that this method can quickly and accurately detect various defects in the E-TPU midsole.展开更多
Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plan...Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plantar force,the peak plantar pressure,force-time integrals and pressure-time integrals,and one-way analysis of variance was used to analyze the performance of the designed cushioned shoes.The results revealed that in normal walking and jogging states,compared with the commercially available sport shoes,the peak plantar pressure in the heel region decreased by 13.65%and 6.05%,respectively.The peak plantar force decreased by 15.98%and 15.32%,respectively.The force-time integral decreased by 4.36%and 6.83%,respectively,and the pressure-time integral decreased by 10.58%and 11.00%,respectively.In conclusion,the cushioning performance of shoes is related to the exercise mode.For normal walking,the designed cushioned soles absorbed greater impact in the heel region,which was effectively cushioned,whereas in the jogging state,the designed cushioned soles exhibited a favorable cushioning effect in the forefoot region.The designed cushioned soles exhibited cushioning performance through the coupling design of material and structure,which effectively reduced impact force when landing and could optimize plantar pressure distribution.展开更多
文摘In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper proposes an E-TPU midsole surface defect detection method based on machine vision to achieve automatic detection and defect classification. The proposed method is divided into three parts: image preprocessing, block defect detection, and linear defect detection. Image preprocessing uses RGB three channel self-inspection to identify scorch and color pollution. Block defect detection uses superpixel segmentation and background prior mining to determine holes, impurities, and dirt. Linear defect detection uses Gabor filter and Hough transform to detect indentation and convex marks. After image preprocessing, block defect detection and linear defect detection are simultaneously performed by parallel computing. The false positive rate (FPR) of the proposed method in this paper is 8.3%, the false negatives rate (FNR) of the hole is 4.7%, the FNR of indentation is 2.1%, and the running time does not exceed 1.6 s. The test results show that this method can quickly and accurately detect various defects in the E-TPU midsole.
基金Education Research Project of Fujian Province,China(Nos.JT180378,JA14265)Science and Technology Program of Quanzhou Normal University,China(No.2013KJ04)Quanzhou City Science&Technology Program,China(No.2016Z071)。
文摘Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plantar force,the peak plantar pressure,force-time integrals and pressure-time integrals,and one-way analysis of variance was used to analyze the performance of the designed cushioned shoes.The results revealed that in normal walking and jogging states,compared with the commercially available sport shoes,the peak plantar pressure in the heel region decreased by 13.65%and 6.05%,respectively.The peak plantar force decreased by 15.98%and 15.32%,respectively.The force-time integral decreased by 4.36%and 6.83%,respectively,and the pressure-time integral decreased by 10.58%and 11.00%,respectively.In conclusion,the cushioning performance of shoes is related to the exercise mode.For normal walking,the designed cushioned soles absorbed greater impact in the heel region,which was effectively cushioned,whereas in the jogging state,the designed cushioned soles exhibited a favorable cushioning effect in the forefoot region.The designed cushioned soles exhibited cushioning performance through the coupling design of material and structure,which effectively reduced impact force when landing and could optimize plantar pressure distribution.
