Winder application

Hi all,
We have plastics embbossed machine using emerson DSI controller and ES2300RG dc drive for pull roll, treat roll and winder roll. We want to replace the old controller using Controllogix. For tension controller, we use the analog output to control dancer roll.
How to implement diameter calculation, torque control and tension control using controllogix? Any idea?
Thank you for help.
James

James, you really need to hire a system integrator with winder experience for this job. Winder applications are deceptively complex and I will not attempt one without my winder-experienced buddy standing by my side.

Please take my advice as well-intended and not an unwillingness to help. We help people with drive applications on here all the time and enjoy it but this kind of application simply demands a higher specialized level of expertise.

Q1. Are you replacing the DC drive as well ?
Q2. Ignoring the fact that you are using controllogix, would you still ask the questions about how to calculate diameter, torque control etc?

Winder Application

Thank you Simon,
We still use existing Emerson DC Drive.
BTW, I want to know how to calculate actual diameter of material, tension control and taper torque. We use dancer roll to control the tension. Dancer roll need 4-20mA signal to control the tension. Tension setpoint will setup using 10K pot (0 - X lb). My idea for tension control is using PID to generate the control signal. My dificulties is calculate the diameter and use this number to setup control the torque. The existing is using linear taper to control the tension if material build-up.
Basically, how to impelement the diameter calculation? Relation between diameter, torque and tension?
Hope anybode can give the idea. Thank you
James

If you know the thickness of the material (caliper) and can keep track of the length, you can calculate the rewound roll diameter by calculating the cross-sectional area (length x caliper).

Length x caliper = PI x (OD^2 - Core_Diameter^2)/4

If you know the line speed and can get a signal at each revolution of the rewound roll, you can keep track of the time per revolution and calculate the diameter from that. The time per revolution multiplied by the line speed gives you the circumference of the roll.

Concerning roll diameter:

1.(Roll RPM) x (Roll Circumference) = (Material Speed)

and 2. (Roll Circumference) = (Roll diameter) * (pi)

Thus Roll Diameter = (Material speed)/(roll rpm * pi).

Usually you do not use this calculation until the machine speed goes above a threshold value to prevent errors due to the division process and the dancer movement. The (Line Speed) and (Roll rpm) values are also normally filtered. For a winder, you also make the diameter only increase in value when running.

Is your drive set-up as a speed controller or a torque amplifier ?

Winder Application

The drive was setup as current mode (troque amplifier).
Its mean that Roll Diameter = (LineSpeed)/(RollSpeed*Pi)
How about the diameter increase if during machine accel or decel?
Speed threshold its mean we set minimum speed to start diameter calculation (say >40% of full speed)?
How to calculate accurate material length with known diameter?
How to calculate the inertia compensation during accel or decel?

Speed threshold for enabling calculations typically 5%

For a centre driven rewinder, the generalised calculation for the torque at the roll is as follows:

Total Torque = Tension Torque + Friction Torque + Inertia Torque

Tension torque = Web Tension * Roll Radius

Friction Torque = Static Friction + dynamic friction.
(a lookup table is usually used contain friction loss against roll rpm)

Inertia Torque = Total Inertia * Roll angular Acceleration
(total inertia consists of Fixed inertia from motor/pulleys/belts, core inertia (may be variable from run to run) and roll inertia which is diameter dependant.

The effects of each of these components depends on the relative size of your rolls/motors etc, but if your predicted torque model takes all these factors into account, you will be able to use this system for most winders.

You will also need a PID controller to trim the predicted torque based on the dancer error. Again, depending on the diameters involved, you will probably need to profile gain with diameter.

Winder Application

The material is plastics.
We have two modes of operation of the Surface Center Winder. Mode 2 is for normal winding.
Mode1: the winding system uses a combination of center drive and surface drive to wind the roll. The spindle drive is dancer position controlled with dancer loading.
Mode2: will be normal center winder. This is for normal winding.
We will provide selector switch to select the mode.
How to control these modes? such as tension control for surface winder?

We have 6 drives for complete embossing film line. We use embosse drive as master speed. The other drive such as chill, pull rolls, treater will follow the master speed. How to setup draw ratio between master and follower?

For the current controller, the encoder feedback and current feedback is connected to controllogix. How to implement current controller pid? What the difference between speed controller and current controller?

Hm, As DickDV says, i think you need a systems integrator.

Winder Application

Where to get the knowledgebase of winder application? Could you suggest any websites or books?
Thank you

There is a huge body of knowledge about winding paper available through TAPPI, the Technical Association of the Pulp & Paper Industry.

http://www.tappi.org