Today, an information gap exists between log measurements performed in the forest and at the sawmill. By applying a code in the forest during harvesting and then reading it at the sawmill, this information gap would vanish. A log applicator, which applies two-dimensional log codes through the saw bar, and a corresponding detection system based on vision technology have been developed. Key features of this technology are the very low cost of each mark and the zero-time-loss characteristic of both marking and detection. A field test utilizing this equipment was performed on 210 logs in northern Sweden in December 2009. For logs harvested during real harvesting conditions and automatically detected at the log sorting station of a running sawmill, a detection rate of 40 percent was achieved. A comparison between parameters (length and diameter) measured in the forest and at the sawmill is presented, as are a number of suggested improvements to increase the detection rate substantially.
Contributor Notes
The authors are, respectively, Researcher, Professor, and Researcher, KTH Machine Design, Stockholm, Sweden (bjornmm@kth.se [corresponding author], janwi@kth.se, hellgren@kth.se). This paper was received for publication in May 2011. Article no. 11-00070.