基于多通道信息处理和缺陷图像重建的木材应力波无损检测技术研究

The research trends of wood non-destructive test based on stress wave have two directions mainly. The test process uses global information instead of local information and the approximately qualitative detection develops to accurately quantitative detection. The research of wood nondestructive testing technology based on multi-channels information processing and decay image reconstruction matches well with the trends. In our research, in order to improve the signal acquisition precision and the data accuracy of the multi-channels stress wave in non-destructive testing process, the multi-channels stress wave signal will be first estimated accurately based on the power transferring model of stress wave in wood. According to the stress wave data from the multi-channels, the space distribution feature extraction method of frequency response will be studied for better recognition of internal defect of wood and higher quality defect image reconstruction.Finally, we will study the defect image reconstruction method of multi-channels stress wave in wood non-destructive testing. According to the spatial relativity between the power transferring model of multi-channels stress wave in wood and the frequency response feature of wood, the 2D and 3D reconstruction of the internal defect in wood are studied to determine precisely the information of wood defect as spatial location, size, figure and density distribution, which means the realization of accurate quantitative inspection for wood. The research results will help to improve the precision and practicability of stress wave non-destructive testing technology and it is promising for application.

木材应力波无损检测的研究趋势主要有：利用局部信息发展到利用全局信息，模糊定性检测发展到精准定量检测等。本项目提出的基于多通道信息处理和缺陷图像重建的木材应力波无损检测技术研究符合上述发展趋势。将首先研究基于能量传递模型的多通道应力波信号精准估计方法，以提高多通道应力波无损检测的信号采集精度和数据准确性；研究木材频率响应的空间分布特征提取方法，依据精准获取的多通道应力波信号，准确、高效的提取木材内部频率响应的空间分布特征，以更好地进行木材内部缺陷识别和图像重建；最后研究多通道应力波木材无损检测图像重建方法，依据多通道应力波能量传递模型和木材频率响应特征的空间相关性，对木材内部缺陷进行二维和三维重建，从而准确检测缺陷的空间位置、尺寸、形状及密度分布等信息，实现木材内部缺陷的精准定量检测。项目的开展能对应力波无损检测领域的理论研究起到一定的推动作用，有助于提高检测精度和实用性，具有广阔的应用前景

木材的无损检测对于提高生产效率和保证木材产品质量具有重要意义，而木材应力波无损检测技术使用方便、成本低、对人体无害，因此受到国内外的广泛关注。目前，该技术的理论研究尚未成熟，其中有若干关键科学问题有待解决。为此，本项目围绕几个方面开展了较为深入的研究。研究了基于能量传递模型的多通道应力波信号精准估计方法，提高了多通道应力波无损检测的信号采集精度和数据准确性；研究木材频率响应的空间分布特征提取方法，依据精准获取的多通道应力波信号，准确、高效的提取木材内部频率响应的空间分布特征，更好地进行木材内部缺陷识别和图像重建；最后研究了多通道应力波木材无损检测图像重建方法，依据多通道应力波能量传递模型和木材频率响应特征的空间相关性，对木材内部缺陷进行二维和三维重建，从而准确检测缺陷的空间位置、尺寸、形状等信息，实现了木材内部缺陷检测。在此基础上，研发了多通道应力波检测仪及木材截面成像系统，通过实际测试来验证提出的理论和方法。项目的开展能对应力波无损检测领域的理论研究起到一定的推动作用，有助于提高检测精度和实用性，具有广阔的应用前景。