Measurement of lumber moisture content based on PCA and GS-SVM

Abstract

Lumber moisture content (LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products. Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of the course of drying, by interference factors that exist in the dryness environment and by the physical characteristics of the lumber itself. To improve the measuring accuracy and reliability of LMC, the optimal support vector machine (SVM) algorithm was put forward for regression analysis LMC. Environmental factors such as air temperature and relative humidity were considered, the data of which were extracted with the principle component analysis method. The regression and prediction of SVM was optimized based on the grid search (GS) technique. Groups of data were sampled and analyzed, and simulation comparison of forecasting performance shows that the main component data were extracted to speed up the convergence rate of the optimum algorithm. The GS-SVM shows a better performance in solving the LMC measuring and forecasting problem.