Blue Stain and Check Detection

The forest industry in British Columbia is now faced with millions of cubic meters of bug killed wood with no end in sight. In order to economically and efficiently process this bug killed wood, sawmill Primary Breakdown Optimization Systems need to have the ability to recognize additional physical characteristics such as Blue Stain and Checks. The ability to recognize these defects and factor them into the Optimized Breakdown Decision will provide significant increased value to our customers.

At Porter we have developed a “Blue Stain and Check Detection System” consisting of a Color Camera based Vision System and utilizing a new model of laser scanners from Hermary, the DPS 4024VE.

Two high-resolution digital color cameras are mounted on the Auto Rotation Conveyor of a Canter and the Hermary scanners are located at the Rotation Conveyor Scan Zone. As the log travels down the conveyor, the cameras acquire a full color image of the leading and trailing ends of the log and the Hermary scanners return greyscale images along the length of the log along with log size and shape information. The camera and scanner images are processed and information outlining the Stain and Crack locations are sent to the Primary Breakdown Computer Optimization System.

Consequently, the very best Optimum Log Rotation and downstream canter solution is determined factoring in these two new variables. It is easy to recognize that a Check in a log that is rotated such that the Check is located horizontally is a considerably less risky solution from a value point of view than a Check that is placed vertically. Similarly, with Blue Stain the heartwood and sapwood locations are mapped by the Vision System allowing the optimizer to factor in different values for both. This system can be fully integrated with our Optimization Systems.