A North American lumber company commissioned innovative Kiwi-developed technology in its sawmill at the end of last year.
Algoma Lumber in Algoma, Wisconsin, uses Albany business Camsensor’s
multiplexed smart cameras and Mt Maunganui-based Automation & Electronics’ (A&E) attendant controls and software interfaces to do its flitch inspection and optimise flitch edging and plank cutting.
A&E managing director Brian Smith says Algoma contacted a Louisiana-based associate towards the middle of last year with a view to replacing its manual secondary infeed with a computerised scanning and optimisation system. A&E has a pre-existing partnership with this associate, a long-established manufacturer of edgers and trimmers.
This partnership had earlier developed a new single or dual infeed system. The system operates with a combination of multiplexed industrial cameras or infra red and invisible lasers, and A&E’s new high-level scanning and optimisation software for the hardwood timber board edger.
A&E/Camsensor connection
A&E had some time ago implemented a similar system for an Australian client, but with another technology partner using different technology.
“For this application, however, we required Camsensor’s technology,” Smith says. “The environment lends itself to it well. It was possible to work around the constraints of the physical distance the cameras need to be mounted from the infeed to obtain a satisfactory field of vision, and the lighting in the environment is good.
“The clients also wanted an actual image of the board instead of a computer generated one as it would enable
them to make further decisions based on the locations of defects in the flitches.”
This is not the first time Camsensor and A&E have combined forces to address sawmill challenges. Recently they partnered technology on a project in Australia, and six years ago they commissioned a log optimisation system for Rotorua-based Tachikawa Forest Products (NZ).
“It’s always a pleasure to have Camsensor as our component supplier,” Smith comments. “For the Algoma project in particular it would have been very difficult to develop another scanner which could provide the level of resolution at the speed that the Camsensors are providing. Camsensor managed to fit in around the numerous mechanical design issues and never failed to meet specifications, which kept evolving throughout the project.”
Flitch optimisation the
2007 way
Following A&E’s assessment of Algoma’s situation, the lumber company opted for the dual infeed system. The company’s mill processed a range of species including red oak, white oak, popular, ash, elm, and cherry.
Smith, and Camsensor managing director Robert Hodge, explain the technology that facilitates the system as follows.
As the flitches are crossfed into the secondary infeed, multiple smart cameras operating with image recognition software capture an image of both sides of the board from the top at high resolution using specialised lighting.
The cameras send the board wane profile data through the Ethernet interface to the A&E optimiser, a high-speed Pentium processor, sitting next to the sawmill operator. The software automatically optimises the data, evaluating the board and calculating the optimal cut pattern for it. The software bases this solution on pre-entered value dimensions and within parameters that reflect the volume or dollar value desired by the sawmill owners. Value dimensions can be reset as and when owners prioritise the product mix differently.
A high-resolution board image is then displayed on the computer screen, showing the optimised board with computer generated overlaying saw lines. The optimatisation software, via the Ethernet to the PLC, automatically orientates the flitches and sets a saw pattern.
However, the system also has a manual mode if required for difficult grading decisions that fall outside the solution parameters. For example, if the operator notices a defect in the flitch, he or she can manually downgrade the solution using hand controls to move saw lines on the computer screen to the next available position. The system incorporates the intervention, self-adjusts, and resets a new optimal cut pattern.
The software communicates the optimal cut pattern data to the saws, which have servo-hydraulically moving positioners, and which then cut the flitches into boards and remove their edges.
Benefits to the sawmiller
The result is an increased throughput and a higher value product.
“The automatic pre-positioning of boards at the edger dramatically reduces the cycle time and decreases operator error. The yield and value of the final product raises significantly as optimised solutions can be weighted according to dollar value rather than operator evaluation; a significant advantage for the sawmill owner,” Camsensor’s Hodge says.
He explains that the rugged smart camera inspection systems are custom made to suit tough environments such as in sawmills.
“The compact stainless steel housing is fully IP67 rated, which means it is sealed against solids and liquids to a very high standard. The smart camera is shock and vibration proof and can be hosed down to clean it.
“Our experience with the development of smart cameras reaches back over a decade and our technology rivals the systems of large global competitors at a fraction of their costs,” he says.
Smith’s take on the advantages of the system incorporates a different perspective. 
“It is basically designed for a close-coupled environment where the mill owners want some form of optimisation but have no space to change the configuration, so they can just take out the existing infeed and drop in place the new system,” he says.
Tachikawa simpler,
but equally effective
Compared with the Algoma project, Smith says, the Tachikawa project in New Zealand “was not as advanced, a totally different and a much simpler application.” But nevertheless, he adds, it was very satisfying as it resulted in a dramatically increased throughput.
According to the company website Tachikawa’s two sawmills specialise in Douglas fir and radiata pine processing and has an annual output of 220,000 cubic metres green and kiln-dried lumber products. It sources raw material logs from central North Island forest owners and sells 36 percent of its products to Japan, 20 percent to the New Zealand market and the balance to other Asian countries, the Middle East, and the US.
Hodge explains the system commissioned for Tachikawa: “To achieve the best throughput and optimal cut pattern, each log ideally needs to be lined up manually at the header saw. In practice this is much too time consuming. This is where machine vision comes in to automatically position the logs before the stationary header saw to reduce operator input.
“When the log is travelling transversely at the entry to the header saw the system measures the diameter of both ends of the log. This gives the centre point of the log and the horizontal and vertical diameter of the log ends. From this information the PLC adjusts the log position to ensure the cuts will be made centrally down the log.
“It also determines the number of cuts depending on the log diameter. Once the camera has processed the images using the preloaded measurements, it shows the operator the cut patterns overlaid on the log, which he can then verify or modify as necessary. The inclusion of this Camsensor technology increased Tachikawa’s throughput by up to 33 percent,” says Hodge.
Home-grown, internationally appreciated
Camsensor also offers five other locally developed applications for machine vision quality inspection, production control, and process optimisation for the timber industry. These are timber profiling, clipper control, MDF grading, veneer grading, and grade mark reading. All applications have been widely applied in Australia, New Zealand, and North America with a variety of technology partners.
A&E’s reputation stretches further than the design, manufacture and servicing of electronic equipment for the sawmilling and forestry industry. The company also has a diverse base of SCADA and PLC based applications for other types of industry applications such as flour, salt, concrete, and hydropower. Its skills base includes software writing, PLC design and programming, panel building, electrical switchboard design, technical writing, CAD drawing, and electronics servicing.
In 1995 A&E developed the MOF scanner in response to the request from mills to provide a low cost solution for computerised control of the first cut. Its range of log scanning technology also includes fully optimised 3D log scanners.
It has a close association with Canadian based technology partners MPM Engineering and Autolog Systems. MPM is a recognised leader in log optimisation and control of machinery used in log bucking and primary breakdown processes. Autolog specialises in 3D carriage scanners and small log line scanners.
A&E has been certified ISO9002 for more than nine years, and recently completed accreditation to ISO9000:2000. The company was the winner of the 2005 Export New Zealand ‘Exporter of the Year’ award for the Bay of Plenty region.
Hodge is proud of the fact that the Camsensor range of applications is fully New Zealand based, developed and owned. “We are producing cutting-edge technology. The company celebrates a decade in business this year, so we must have been doing something right to not only survive in this competitive environment, but also show good growth,” he says.