Winder Application

Gents:

I have a project that I am reviewing right now. I have a customer that has a proprietary controller that controls the speed of a spindle drive. Operator Entry Points are as follows: Yarn Length, Starting Spindle Speed, Stopping Spindle Speed etc and time. etc..The controller has two inputs from prox switches. One switch is for spindle speed and the other is for a roller speed above the spindle which is a set to a constant speed. These proxes just relay speed signals to the controller. Then, the controller sends a 0-10VDC signal to a drive to control the speed of the spindle.

It appears to me that this old controller is basically handling a winding function. The name of the controller is EPIS and it is German.

We are reviewing replacing this controller with an Allen Bradley PLC and a Panelview Plus. I know that a new drive could handle this onboard but we were looking at keeping the existing drive.

Has anyone built winder profiles in a PLC like this?? Any suggestions would be very helpful. i was thinking some sort of PID or something like that..

Thanks,

Since no one else jumped in, I'll start.
Are you just replacing the controller or do you plan to change the control theory?

Is there any tension feedback on this thing (dancer, load cell, etc)?

Am I correct in interpretting that you have a driven lay-on roll AND a driven winder spindle?

It sounds like you are winding yarn. Do you have a traverse assembly that controls how the yarn is laid on the spindle or does it just fall where it may?

Is this actually yarn or is that just a term they use?

What is the product stiffness and how much tension do they run?

Are you sure the command going to the spindle drive is speed? Could it be torque?

I have done several different winder controllers in plcs. It is certainly do-able. The big thing, as with any plc project, is clearly defining what you want to accomplish before you start. It's not a programming thing; its a concept thing.

Keith

I don't plan on changing the process. We just can't get the PC's repaired or replaced so we have to duplicate it with something off the shelf..



There is no tension feedback going to this EPIS controller. It appears that they are manually setting the tension.


No, it is not a driven layon roll. basically, a large roll of Lycra or equivalent material is on the top of the machine. the end of the spool is intertwined between quite a few rollers and the last roller before it goes down to the spindle is driven at a constant speed. I'm familiar with lay on rolls and it is not a lay on roll..

There is an assembly that runs up and down across the spindle to wrap the fiber.

In regards to the tension, it must be a good bit of tension on the machine because the fiber starts off fat and ends rather thin..

It appeared to be speed but it may very well be torque...
Thanks,

Eurotherm/SSD/Parker sells an 'integrator' version of their 590/690 drives that has a bit of logic ability, as well as built-in winder application macros.

As I said in my first post, I have little doubt that a plc can handle this application. The only point of doubt is how fast are you running and does the plc you want to use have high speed inputs if you are running fast.

However, the biggest concern is still how is this thing supposed to work. You are at a point where you need to decide if you want to do this the way it was done before or do it the way you want to do it. The two may well be the same but they are approached differently.

If you want to do exactly what was done before you need to get some additional information. The first piece of info might be does the command voltage to the rewind spindle increase or decrease as the rewind diameter grows. If it increases it's torque based, if it decreases it's velocity based. Does the command change in steps? If so, do those step changes occur when you get a spindle revolution prox input or when you get a change in direction of the winder thread traverse guide?

If they are doing a velocity based system I have to believe they are basing the speed reference simply on the number of layers of yarn laid down on the rewind spindle. This can be a bit of a touchy system as you need to know the thickness of a layer to get this to work right. It sounds like with your material the ultimate thickness of a layer will end up being the entered thickness as the material will shrink under tension and grow as tension is relieved.

I don't understand how the proxes fit in if this is a velocity based system with no tension feedback. Usually the proxes would give you a relationship between the rotational speeds of the rolls they monitor, allowing you to calculate roll diameter. But thism only works right if you have some type of feedback control to modify the spindle speed in order to get the desired tension. In the absense of feedback control both the roller above the spindle and the spindle itself will go the speed they are told to go by the controller. The proxes will tell you something you already know.

Now, if this is a torque based system the proxes can be used to calculate roll diameter as the spindle will only go as fast as the material coming into the spindle will let it go. So in that context the proxes make more sense.

jbrandt is right about the Eurotherm drives, as well as many others. As plcengineer stated in his original post there are several that will do built-in winding. But keep in mind these winder macros are pretty typical winders. They will either want tension feedback or they will basically be torque based winders. If you are doing something a little more custom the drive based functions don't get you much.

To a large degree this is a question of resources. Can you build and commision your own winder function for less total cost (both time and materials) than using a drive based system? This is the big question to answer once you define yor project and can compare that to what is available.

Keith

I do lots of winding applications with constant and ramped tension control as well. My products are strips of semi-elastic rubber coated materials. My lines all have a winder input loop in which the stock hangs feely in front of a loop height sensor. I calculate the min. and max. ratios between the winding operation and the conveyor feeding the winder. I use a PID block with the loop height as the PV. The CV is rescaled between the two ratio limits. I multiply the feeding conveyor line speed times the ratio calculated using the PID and send that speed command to the winder drive. This method allows flexibility to deal with changing stock thicknesses and stretch. It also stops and starts much more smoothly than when using PID alone to generate a speed reference without consideration of the feeding conveyor velocity. If your line runs continuously, PID with loop height or load cell PV and drive speed ref. as the CV will work fine. If your line stops and starts frequently, or changes speeds frequently, the PID rescaled as a ratio multiplied by the line speed will work better.

If you want to keep the existing motor control take the time to look at the "Carotron" cortex interface unit. We use them in center winding / unwinding units. They take the guess work out of the programing.
Lynn