Machine Strength Grading Using Smart Image Sensor for Defect Detection
Lars Boström
ABSTRACT The smart image sensor enables several improvements with respect to machine strength grading compared to the normal CCD camera technique. With the smart image sensor different timber characteristics such as dimensions, geometry and surface density can be measured simultaneously. In the present study only the image of the so-called tracheid effect has been used in order to characterise the knots in the timber. An advantage with the measurement of the tracheid effect compared to normal greyscale, or colour, images is the ability to detect light knots on species such as Norway spruce and of timber with sawn surfaces. The knot characteristics together with the results from a normal bending type grading machine have been combined and the improvement of the system have been determined. The experimental results performed on 800 pieces of timber show that the grading accuracy increases when the smart image sensor is combined with the grading machine.
Publication Source: WCTE '98 - 5th World Conference on Timber Engineering, 1998 August 17-20, Montreaux, Switzerland.
Vol. 2, Pages 312.....
Publisher: Presses polytechniques et universitaires romandes - [Homepage]
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