Wood processing industry

Vision based veneer cutting process optimization

Challenge: To shape veneer layer based on its quality, thickness, set of predefined templates and presence of defects. Implement a real-time decision making and continuous area optimization algorithm that handles presence of this defects.

Difficulties: When thin layers of wooden material are peeled from the rotating log irregular defect such as holes, cracks, insufficient width etc. frequently emerge. Large widths (up to 3 m) and transport speeds (up to 2 m/s) need to be taken into account.

Solution: PC-based vision machine control system consisting of NI PCI data acquisition cards, several firewire cameras, backlight illumination and running NI LabView program which implements extensive use of NI Vision Development Module functions was used to develop and deploy solution to the problem.

Result: System can detect defects of 2×2 mm² in size, allows cutting with 1 mm precision thus considerably reduces material throw out, implements alignment of first and last cut, controls the speed of veener movement, classification of output sheets based on their quality, type of defects and size, allows detailed process parameterization, considerably increases overall control reliability. The system not only provides optimal material shaping but fully automates the complete cutting machine and controls all main actuators. The RAUTE machine with old PLC based controller and photocell sensing for defect and unreliable behaviour has been upgraded with high-end modular, fully software configurable and extendible solution.