Segmentation of micro-cracks in fractured coal based on convolutional neural network
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摘要: 深部开采导致的煤岩裂隙结构的延伸、贯通及扩展是引起煤岩破坏的关键因素。裂隙结构的准确表征是分析煤岩破坏机理及开展煤与瓦斯绿色共采的核心要素之一。本研究采用Waifu2x卷积神经网络模型对裂隙煤岩CT图像进行处理,获得分辨率更高的CT图像。并提出“裂隙煤岩标注七步处理法”,提高了标记效率,采用图像增强技术扩充训练集,满足了模型对于训练集数量和质量的要求。采用训练后的U-Net卷积神经网络进行图像分割,提取煤岩内裂隙信息。通过对比发现,本方法所获得的裂隙连通性、开度及分布与真实CT图像更为接近,所提取的裂隙4个量化指标均优于其他提取方法。研究为裂隙煤岩物理力学行为及机理分析提供基础。Abstract: The extension, penetration and expansion of coal and rock fracture structure caused by deep mining are the key factors that cause coal and rock damage.Therefore, the accurate characterization of the fracture structure is one of the core elements for understanding the coal and rock failure mechanism and developing coal and gas green co-mining.In this study, the Waifu2x convolutional neural network model was used to process the fractured coal and rock CT images to obtain CT images with higher resolution.And put forward the "seven-step processing method of fissure coal and rock labeling", which improves the efficiency of labeling, and uses image enhancement technology to expand the training set, which meets the model's requirements for the quantity and quality of the training set.The trained U-Net convolutional neural network is used for image segmentation to extract the fracture information in the coal and rock.Through comparison, it is found that the fracture connectivity, opening and distribution obtained by this method are closer to the real CT images, and the four quantitative indicators of the extracted fractures are better than other extraction methods.This study can provide a research foundation for the physical and mechanical behavior and mechanism analysis of fractured coal.
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表 1 环境硬件配置
Table 1. Environment hardware configuration
项目 系统 CPU 内存 GPU 参数 Windows 10专业版 Intel i7-7700HQ 16GB GTX1060 6G 表 2 环境软件配置
Table 2. Environment software configuration
项目 Python Keras Tensorflow Cudatoolkit 版本 3.6 2.1.6 1.14.0 10.0.130 表 3 不同算法裂隙提取准确性评价
Table 3. Accuracy evaluation of different crack extraction algorithms
评价指标 U-Net卷积神经网络 全局阈值分割 局部阈值分割 Weka机器学习 PA 0.981 0.976 0.942 0.973 MPA 0.868 0.771 0.785 0.809 MIoU 0.797 0.729 0.619 0.730 FWIoU 0.966 0.956 0.916 0.954 -
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