Using arduino for rotogravure printing register sensor

I have old rotogravure printing machine with manual type register control. Any suggestion how to use arduino to automate my machine? thanks

You will have to supply a LOT more information. You can start by telling us exactly how the "manual type register control" works.

During the gravure printing process the printing cylinder rotates in the ink pan where the engraved cells fill with ink. As the cylinder rotates clear of the ink pan, any excess ink is removed by the doctor blade. Further around, the cylinder is brought into contact with the substrate, which is pressed against it by the rubber covered impression roller.

The pressure of the roller, along with the capillary draw of the substrate, results in the direct transfer of ink from the cells in the printing cylinder to the surface of the substrate. As the printing roller rotates back into the ink pan, the printed area of the substrate proceeds through a dryer and onto the next printing unit, which is normally a different color or may be a varnish or coating.

Precise color to color registration (Printing registration - Wikipedia) is made possible via side and length register control systems.
My old machine use worm gear to manually adjust both side and length register. For modern machine, a computer through series of sensors and stepper motor do the job which is of course yield much precise job.

latka68:
My old machine use worm gear to manually adjust both side and length register.

OK. So far you have provides one sentence that describes the "manual type register control" process. You will have to provide a LOT more detail if you want an answer to your original question.

Is there a knob you turn?

Is there more than one knob you turn?

How do you know when to turn the knob or knobs?

How do you know in which direction to turn the knob or knobs?

How do you know how much to turn the knob or knobs?

If you want to design a machine to do your job you first have to be able to exactly describe what you are doing.