All Soliton products are based on an in-house developed common technical solution, specially designed to the needs of the wood working industry. A simple, reliable and powerful system was demanded with performance exceeding those of conventional systems.
The solution was to use multisensor cameras combined with laser and a standard PC-computer. A number of new algorithms and methods were also introduced. One of these, the so called Tracheid method, was patented and is one of the methods used by Soliton to scan the wood surface.
The in-house developed multisensor cameras are manufactured using standard components and use smart image sensors. The cameras are very robust and work with high precision at high speeds. The technique in use allow us to use less cameras while still offering a safer, more accurate, defect detection. Three different pictures are taken simultaneously (contrast/grayscale, tracheid and profile) by one individual camera which further increases the system reliability.
Soliton's multisensor camera
Laser is the only light source used. The need for calibration and changes of light source is thereby kept to a bare minimum. The laser is used in order to accurately measure the quality, dimension and profile of the wood piece. The measurement can be done on one to four sides of the piece. When only doing profile measurements up to 10 000 full profiles/second can be measured, which at a speed of 300 m/min is the equivalent of a lengthwise resolution of 0.5 mm. Laser is also a requirement in order to successfully use the tracheid method.
The principle of measurement
The technical solution is based on standard PC-technology with Windows NTTM operating system. The system is therefore easily upgraded as the PC-technology evolves. In Soliton Cross-cutting, for instance, one single computer is used to classify, analyse, optimise and control the following cross-cutter.
The tracheid method combined with laser is patented by Soliton and is based on the so called tracheid effect. When illuminating the wooden surface with laser, some of the light is transferred through the cells of the wood (tracheids) much like fiber optics. This gives a indication of the density of the surface and if there are any disturbances in the fibers. Laser gives Soliton the best prerequisites for safe and accurate detection of knots. (See images below)
The tracheid method is necessary in order to build a powerful, yet simple, scanner solution. It is also the only safe method to detect light knots, blue stain and compression wood.
By combining the tracheid image with the two other camera images (contrast and profile) unique opportunities arise giving Soliton the best possible information in order to classify defects and ascertain quality.