The "Knot-Tearout Real Time Detection" project investigated the possibility of using off-the-shelf true shape laser scanners for the purpose of scanning cants at the out-feed of a canter to detect and quantify cant size and surface tearout. This was done by building a prototype detection system using commercially available IVP [Integrated Vision Products] scanners, developing computer detection and analysis software, and conducting extensive lab and mill tests.
It was found that tearout can be detected and measured with this equipment, but often needs to be distinguished from other surface anomalies. Furthermore, it appears that these other surface anomalies might actually be more valuable to detect since they lead to a loss in recovery and are caused by a variety of canter problems that could be detected and resolved.
The mill tests also revealed that cant shape can be very complex. Furthermore, manual quality control methods may be inadequate for detecting and measuring the details of "within cant" size and shape variations. These details are easily measured by a scanning system, and computer analysis of the scanner data can readily identify different magnitude and types of defects. This could lead to a practical canter diagnostic tool to help identify sources of problems that lead to misshapen cants and reduced lumber recovery.