Three-dimensional stress wave imaging of wood internal defects using TKriging method

In order to detect the size, shape and degree of decay inside wood, a three-dimensional stress wave imaging method based on TKriging is proposed. The method uses sensors to obtain the stress wave velocity data sets by hanging around the timber randomly, and reconstructs the image of internal defect with those data sets. TKriging optimizes structural relationship between interpolation point and reference point in space firstly. The searching radius is used to select the reference points accordingly. Top-k query method is introduced to find the k value with relevant points. The values of the estimated points are calculated and three-dimensional image of the internal defect inside wood is reconstructed. The results show the effectiveness of the method and the accuracy rate is higher than that of basic Kriging method.