Increasing product quality by means of visual signals
Online process monitoring with ibaVision
The task is to detect rhomboidity during a continuous casting process. This needs to be done to allow timely process adjustments and consequently avoid problems in the downstream rolling mill.
Continuous casting is a semi-continuous procedure for manufacturing steel blocks. The molten liquid metal is poured in the mold and pre-cooled, so that the strand has a solid shell of a few centimeters and a large part of the cross section still is in a liquid state. The strand is guided by the machines over strand guide rolls and is afterwards cooled. After it has solidified, the strand is cut on the out conveyor in the desired length by means of a cutting torch.
Without real-time monitoring, the geometry of the cast billets can only be measured on a random basis after cooling. Non-squaered billets and a deviation in the process state can only be detected much later in the process.
This is prevented by continuously monitoring the production plant with an image processing system. The process efficiency and also the product quality are increased with a lasting effect.
process state monitoring
A camera that is installed behind the cutting torch records the front sides on the billets and provides ibaCapture with the video data. ibaVision processes the video sequences and first of all determines the corner points of the front side of the billet and calculates - using these data - the length and the difference of the diagonal. These values are fed in the ibaPDA process data acquisition system as so called visual signals. ibaPDA then creates a long-term trend of these characteristic values. Thus, ibaVision allows for determining numerical values that do not have sensorics. In case of a significant trend, thus a diagonal-difference above a pre-defined threshold, the operator is being alarmed by means of a virtual traffic light on the user interface. The defective billet can then be eliminated. Simultaneously, the settings of the plant are adapted.
"Image processing delivers information that no other sensor can get – and does so 24/7."