Research On Wood Defects Detection Based On Resistivity Tomography Technology

China has a vast territory,rich natural resources,and a large amount of timber resources,but the comprehensive utilization rate of timber is far lower than that of western developed countries.In the growth process of trees,the internal susceptibility to microbial damage leads to different health problems such as fungal infection,knots,and defects,which seriously restricts the efficient use of wood.In addition,when the environmental temperature is different,the ability of microbial activities inside the trees is also different,so the rate of tree disease will also change accordingly.The use of appropriate detection technology can improve the detection ability of wood defects.When the wood has diseases such as decay or defects,the resistivity method can also explore the influence of environmental temperature on wood resistivity and defects from different angles.This paper analyzes the changes in the resistivity of defective wood under different ambient temperatures,establishes an image reconstruction model based on the azimuth search inverse distance weighted interpolation method,and builds a model of the relationship between ambient temperature and wood resistivity.The main work and innovation are as follows:(1)In this study,the collected resistance data is preprocessed and converted into resistivity data,and then the resistivity data is subjected to curvature correction,then a grid model is established to determine the attribute of the reference point,and the azimuth search method is introduced into inverse distance weighted interpolation In the method,a wood defect detection model based on the improved inverse distance weighted interpolation algorithm based on electrical resistivity tomography technology is proposed.The intersection ratio of the simulated image defect and the real defect image of the improved model is 60.04%,which is 5% higher than that before the improvement,and the center deviation rate of the simulated defect is 0.81%.The improved inverse distance weighted interpolation method fully considers the location information of the reference point,and can predict the defect information of the defective wood more accurately.(2)Studying the relationship between environmental temperature and wood resistivity,it is found that when the moisture content of wood remains unchanged,as the ambient temperature decreases,the resistivity of wood samples all show an upward trend,and wood resistivity and temperature are negatively correlated,The absolute coefficient R2=0.9,the correlation between the two is significant(P<0.05).The resistivity of wood defect locations is 3-5 times that of healthy locations,and this gap becomes more obvious as the temperature decreases.