In Wire Rod Mill (WRM) of steel plant the end product is in coil form. The coil is formed at 550 to 900 oC by a rotating head called laying head and positioned at the end of the mill line. The coil is then transferred by Stelmor conveyor for packaging. The tail end of the coil gets misaligned from the rest of the coil (it takes much bigger diameter) heap and could get entangled with the other parts of handling device and might get stuck in the passage. When it gets stuck, it may cause damage to the finished product and may lead to stopping of the production line.
To avoid the above situation, currently, the tail end is manually set right by a person using a long rod while the red hot coils are moving toward the Stelmor conveyor.
As shown in the figure 1, the red hot coil is placed on the intermediate conveyor. The conveyor moves at a speed of approximately 10 cm/s and goes in to a cooling zone. After coming out of the cooling zone the coil is fed into a vertical mandrel (figure 2). The front end of the coil is well placed inside the coil diameter by the laying head but the tail end comes out in a haphazard manner. Most of the time, the tail end is outside the coil loop as the conveyor drags the coil. If this is left as it is, it will get entangled while entering in to the vertical mandrel. Therefore the tail end is manually positioned every time.
An operator lifts the tail end and places the tail end inside the formed coil loop. After proper placement of the tail end the operator comes out of the work zone with the tool. All these operations are done while the coil is in motion.
There are two problems associated with this:
The desired solution should (with no humans) first identify the misalignment of the tail end of the coil and then align it to get similar outcome as obtained by the operator manually. A typical solution would have following steps:
In addition, there are some constraints as below