Lumber Trim Block Sorter               

 There are four main tasks for the typical system:

• Data Acquisition
• Data Processing
• Data Tracking
• Data Reporting

Note: The following details refer to a 30 inch dual (top and bottom) scanner head with 1-inch reading intervals along the board. Different length/resolution scanner systems will be produced on customer demand.

1.1 Data Acquisition is performed using the following hardware:

•          Custom made scanner head (30 inch long) with 54 Baumer distance measurement laser sensors

•          Encoder, 2000 pulse/rev in conjunction with a proximity switch for lug interval detection

•          IBM compatible computer for board data capture – Data Acquisition Application

 The custom scanner head takes measurements at 1-inch intervals along the board length and at 0.030-inch intervals along the board width.  The Data Acquisition application reads the scanner head sensors, creates individual block profiles for each of the sensor pairs space and sends the whole board data to the Data Processing application for data manipulation and sort designation.

 1.2 Data Processing is executed by:

•          IBM compatible computer for board data analysis – Process Application

 The Data Processing application receives the board data from the Data Acquisition application and calculates the overall block dimensions and wane free top, bottom and side faces. The preliminary results are compared to the active board type parameters and a sort category is designated for the wood block (if a good match is found the board will be sent to one of the walking bins, else is sent back for re-processing: trimming, edging). The board sort category is sent to the PLC for Data Tracking. If there is any operator override when the board arrives at the operators’ station, the PLC sends the result back to the computer to replace the sort category and also sets an override flag for the corresponding board in the queue.

 1.3 Data Tracking is controlled by:

•          Programmable Logic Controller – PLC

•          Encoder, 2000 pulse/rev in conjunction with a proximity switch for lug detection

 The PLC receives the sort category associated to the active block from the computer; the PLC receives also input from two operator stations. Any of the operators can override the scanner-computer decision by pressing the sort buttons while the present board is passing through a precisely delimited zone. This action will replace the computer generated sort category assigned to that board in the data tracking system. The operator stations have been designed for the special cases when the board presents defects invisible to the scanner (end defects, knots, dark spots) and for the manual mode, a back-up when the computer is down.

 The blocks are tracked and diverted automatically into one of the defined sorts based on the final sort designation.

 1.4 Data Reporting uses:

•          IBM compatible computer for shift / history reports and system parameter printouts – Report Application

•          Laser printer

 The Report computer continuously receives board data from the Process computer and displays on its main screen on-line shift production data, board counts and last ten boards details. It also offers access to viewing and printing system parameters or history files (previous shift summaries). The Report computer stores the shift data into a database for shift and history report generation.