Hi,
We've come across a customer plant having problem with their aluminium feeding machine.
Referring to the attachment, the roll of aluminium foil is feed into the machine. In between there is an analog displacement/distance sensor to control the speed of the feeder motor. If it's a new roll, the motor will turn slower, if the roll almost finish the motor will turn faster so that the feed-in speed into the machine is constant. When the roll almost finish, the distance from the analog sensor to the aluminium foil will be greater. The analog signal from the sensor will feed into a PLC 5/30 and the output to control the speed of the motor is from a PLC analog output module (0 - 10V).
The problem is, now the motor feeder is running fast and slow (not consistent), because the aluminium foil will fluctuate during running, and when the sensors sense the fluctuation, it'll cause the motor to speed to fluctuate also. When this happen the aluminium will fluctuate even greater because they are like a PID loop!
We tried to put a timer in the PLC program, so that the PLC 5/30 will capture the sensor signal only every 10th second. And update the output every 10th second.
This does not help much, is there any better solution out there?
Hope to hear from you guys. Thanks.
We've come across a customer plant having problem with their aluminium feeding machine.
Referring to the attachment, the roll of aluminium foil is feed into the machine. In between there is an analog displacement/distance sensor to control the speed of the feeder motor. If it's a new roll, the motor will turn slower, if the roll almost finish the motor will turn faster so that the feed-in speed into the machine is constant. When the roll almost finish, the distance from the analog sensor to the aluminium foil will be greater. The analog signal from the sensor will feed into a PLC 5/30 and the output to control the speed of the motor is from a PLC analog output module (0 - 10V).
The problem is, now the motor feeder is running fast and slow (not consistent), because the aluminium foil will fluctuate during running, and when the sensors sense the fluctuation, it'll cause the motor to speed to fluctuate also. When this happen the aluminium will fluctuate even greater because they are like a PID loop!
We tried to put a timer in the PLC program, so that the PLC 5/30 will capture the sensor signal only every 10th second. And update the output every 10th second.
This does not help much, is there any better solution out there?
Hope to hear from you guys. Thanks.