The scanning and profiling of logs reduces jam ups at the de-barker by positioning the log at the correct orientation. The system detects if the scanned log should be rejected (in case any parameters are out of spec) or if the log should be re-orientated. Another purpose of the measurement system is the volume determination for yield calculations.
The Q:Scan Log Profile uses three Camsensor smart cameras and three lasers to profile 360 degrees of the log surface to take its measurements. The method of laser triangulation is utilized for that. Multiple captures of the smart cameras based on the encoder build up the log profile or surface map. All the attributes of the log are calculated at the end of the log and results are sent to a PLC via a serial string.
The following measurements are undertaken by the system:
Length: uses the encoder to measure the length of the log as it breaks the laser line. Accuracy ± 10 mm
Small End Diameter (S.E.D): the shortest distance through the small end of the log. Accuracy ± 10 mm
Large End Diameter (L.E.D): the longest distance through the large end of the log. Accuracy ± 10 mm
Orientation: determines whether the SED or LED is coming first along the conveyor, so that the log can be rotated if required to present it to the de-barker with the SED first. Accuracy ± 30 mm
Volume: uses the encoder and the area of each slice to estimate volume based on best fit circles.
Ovality: The variation between the median longest and shortest diameter in the leading 1/3 of the SED side of the log. Accuracy ± 30 mm
Taper: The reduction in diameter along the length of the log.
Sweep: greatest inwards deflection from the ends of the log, in a single plane. Accuracy ± 20 mm
Crook: greatest inward deflection in the log from high point to high point, in a single plane. Occurs if there are two of more deviations along the length of the log in the same plane. Accuracy ± 20 mm
Nodal Swelling: the swelling that occurs around a branch node. It is measured from the top of the swelling to the taper line. Accuracy ± 30 mm
Butt Flare: sudden increase in diameter at the large end of the log. Measured from the tip of the flare to the outside edge of the normal projected taper line. Accuracy ± 20 mm
The system can profile any log diameters and handles any log lengths. It supports line speeds up to 120m/min, and can increase the accuracy with slower speeds. Best results are achieved at a log spacing of 250 mm.