An Algorithm for Log Rotation in Sawmills
Keywords:Log rotation, algorithm, sawmill
AbstractGreat strides have been made in sawmill automation since the first Best Opening Face (BOF) models were proposed in the 1970s. For example, curve sawing techniques have demonstrated strong potential in maximizing the value recovery from sawmills. This paper concerns an important step in maximizing lumber yield in a sawmill, namely log rotation. Rotating the logs to be in the horns up or horns down position just before the sawing process has been shown to have a positive effect on maximizing the lumber yield. We present an efficient algorithm that, upon being fed the appropriate scan data for a log in an arbitrary position, determines the necessary angle of rotation for the log to be oriented (in real-time) in the horns up or horns down position.
Hallock, H., and D. W. Lewis. 1971. Increasing softwood dimension yield from small logs-Best opening face. FPL paper 166: 546-555. USDA Forest Serv., Forest Prod. Lab., Madison, WI.nHarpole, B., and H. Hallock. 1977. Investment opportunity: Best opening face sawing in Paper FPL 291. USDA Forest Serv., Forest Prod. Lab., Madison, WI.nHasenwinkle, E. D., F. Wislocker, and C. Blickenderfer. 1987. Variable curve linebar, U.S. Patent No. 4,633,924, U.S. Patent Office, Washington D.C.nLewis, D. W. 1985. Sawmill simulation and the best opening face system: A user's guide. Gen. Tech. Paper FPL 291. USDA Forest Serv., Forest Prod. Lab., Madison, WI.nLindstrom, N. E. 1979. Apparatus for curved sawing of timber. U.S. Patent No. 4,144,782, U.S. Patent Office, Washington D.C.nManess, T. C., and W. S. Donald. 1994. The effect of log rotation recovery in chip and saw sawmills. Wood Fiber Sci. 26(4): 546-555.nRichards, D. B., W. K. Adkins, H. Hallock, and E. H. Bulgrin. 1980. Lumber values from computerized simulation of hardwood log sawing. Paper FPL 356. USDA Forest Serv., Forest Prod. Lab., Madison, WI.nShi, R., P. H. Steele, and F. G. Wagner. 1990. Influence of log length and taper on estimation of hardwood BOF position. Wood Fiber Sci. 22(2): 141-148.nSteele, P. H., E. M. Wengert, and K. Little. 1987. Simplified procedure for computing best opening face position. Forest Prod. J. 37(5): 44-48.nStern, A. R., H. Hallock, and D. W. Lewis. 1979. Improving sawing accuracy does help. Res. Paper FPL 320. USDA Forest Serv., Forest Prod. Lab., Madison, WI.nThomas, G. B. Jr. 1960. Calculus and analytic geometry. 3rd ed. Addison-Wesley Publishing Company Inc., London, U.K.nWang, S. J., B. D. Munro, D. R. Giles, and D. M. Wright. 1992. Curve sawing performance evaluation. Forest Prod. J. 42(1): 15-20.n
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