How can we sense the edge of a paper and provide feedback?

[adam pal]

In our Binding machine we roll the paper on a rod.
But due to unevenness of the rollers the paper is not rolled properly and it comes out of edeges.
We want to deploy a mechanism that there are sensors on either side of the paper which give feedback to a motor such that when paper moves side ways the motor adjusts the roller such that it moves back to its original position.

[Brent_R]

How much of your system is already defined? What type of actuator do you plan to use and what are it's inputs? Here's one sensor option for you. Ten minutes on Google will probably get you a few more.

http://www.nireco-web.com/epc/sensor.shtml

I'm not sure what type of signal this particular sensor outputs, however I would guess that it is an analog signal of 0-5V, 4-20mA, or something similar. In this case you could take measurements with one of our DAQ boards (or the ADC on the motion controller), calculate a position correction, and send this to the controller (NI 73xx).

The type of amplifier you use will depend on the actuator you have. NI offers a selection of drives (MID series, nuDrive) for low to medium power applications, which may well include
your paper adjustment mechanism. Maybe the actuator has an amplifier built-in.

If you can let me know a little more about the sensors and actuators in your system, then I would be happy to help you select the appropriate measurement and control hardware. It's likely that we will have several feasible options.

Regards,

Brent R.
Applications Engineer
National Instruments