LogProfiler – System for sorting and optimization of logs

The LogProfiler is used for 3D measurements of logs. The LogProfiler is equipped with control systems for log sorting, log turning optimization and post-control as well as sawing pattern optimization. The measurement system consists of two sequential laser perimeters which enables compensation for sideways movement of logs when determining exact log shapes at high line speeds. The new generation digital cameras enable high measuring accuracy by which logs can be further individually identified in subsequent process stages. The LogProfiler can be installed to either straight or side transfer line and can be used with tilt rollers, double tilt rollers or rotary turning.


Basic Specification

Measuring objects Logs, blocks and boards
Size range 10…1000 mm

Operating Principle
The LogProfiler™ system is a laser and camera based system to measure the geometrical dimensions of a log. Its functions with two measurement stations, one for the optimization and one for the recognition of the log at the turning device. This makes the LogProfiler unique in the sawmill industry. Each system also use two lines of lasers for an even better measurement with its movement’s compensation.


Log Sorting
Lineal sorting of logs diameter, volume and length.

Log Optimization
Optimization of logs for sawing into predefined patterns.

Log Sorting
The LogProfiler™ uses LIMAB’s unique dual plane scanning technique with movement compensation to scan the logs with high precision. Movement compensation ensures that vibration and sideways log movement do not influence the measurement resulting in a more accurate 3D model for each log. Knowing the true form correct log sorting and subsequent optimization of sawing process can be achieved to maximize yield. The volume of the logs is calculated in accordance with Swedish legislation.

Sawing pattern optimization
The LogProfiler™ system has a function to sort for various sawing patterns according to the precise 3D model. The sorting table is able to simultaneously handle traditional dimensional sorted classes and pattern optimized log classes. Simulation tools are provided to allow ‘virtual sawing’. This allows the saw mill to establish the best sawing patterns to use to achieve the highest income on a given batch of logs.

Log turning control
Using the log 3D model The LogProfiler™ will determine the optimum rotation position in accordance with the product rules specified by the sawmill. Taking account for pattern or sideboard optimization and amount and position of wane. There is also the possibility to use curve sawing reliably in the evaluation. The system will provide the control signals to the log turning control system.

Unique secondary scanning
LIMAB’s LogProiler™ utilises a secondary scanner mounted immediately before the log turner. This scanner identifies the actual rotational position of the log by matching the surface to the original 3D model. The use of this method means that it doesn’t matter if the logs have rotated on the conveyor. In addition any mechanical slip in the log turning mechanism can be compensated resulting in much more precise sawing and better yield. Furthermore this real time rotation compensation puts less demands on the precision of the turning mechanism.

Movement compensation
LIMAB’s unique dual plane scanning technique uses two laser lines which means that log vibration and sideways movement during scanning do not influence the measurement. This provides much better accuracy in determining log crook and curviness giving the sawmill better yield.

Non-contact measurement for best results                      .

Cabinet and PC
Type and dimensions Rittal 380 x 600 x 210 mm
Protection classIP67 PC HP Z420
PC operating systemLinux Ubuntu, Mint
Interfaces from systemEthernet
Cameras Number of cameras 3
Camera type LIMAB 4MP fully digital
Measuring frequencyLIMAB PreciCura500Hz (every 10mm at >200 m/min)
No of measuring points around log circumferenceDepends on log diameter, typically 1080
Dimensions125 x 125 x 250 mm
Protection classBetter than IP44
LaserDual line LIMAB PreciLine
Operating temperature -40°C ,-> +50°C