Weld Seam Detection

I have an project that I am reviewing that consists of 4 AXIS of motion, welder and a weld detect system. I am looking at using AB CompactLogix with a 4 AXIS motion card, sercos to Ultra 3K servo drives. My issue is this, I need a way to detect a seam that I am going to have to weld. Basically, the customer rolls a piece of steel into a cylinder shape, then puts two end caps on the ends. The final product is a gas tank and I will need to follow the weld seam that the end caps make when put on the tank.

Currently, they are not using servos and they are using a contact type sensor to detect the weld. So, I know that if I can detect the weld accurately, I can position the servos..

Does anyone have any suggestions for devices/vendors to supply a weld detect system. I have seen Laser etc.. The accuracy requirements are not anything elaborate because they are not that accurate now and they are within the specs for the tanks.. I know that we can more accurately place a weld with the servos than with the current system.

Any Help Would Be Appreciated..

Thanks,

I don't know how much help I'll be but here we go.

Currently, they are not using servos and they are using a contact type sensor to detect the weld.

Click to expand...

What are you really looking for? Where to weld or where you have already welded?

I have done some welding with Motoman robots. The robot I worked with had some special stuff just for welding. Including feedback from the welder and arc on/off logic. I would take a look at some of the robot web sites. I would say they would have something that will detect what you want to detect. You may also pick up some other ideas that will help with the project.

Try Omron or Keyence. Both of these companies have a dedicated weld detection sensor. Not sure if it is laser of vision.

These devices look like they are very good but could also be expensive. Either way if you don't need anything quite so elaborate they also have laser and inductive displacement sensors.

I'm looking to detect the seam that I am going to weld. Now, they are using a contact displacement sensor that is really old and doesn't work very well. We are looking at replacing that as well as the motors/drives.

I would go with CharlesM's suggestion and look at how robots are doing it. We looked into using Panasonic in a welding application on time. One thing that amazed me was that the part only had to be within about 1/2" of the correct position. I would say that they are using something like you are looking for.

Let me know if you find out what they are using, I would be curious to know

Hi Plcengineer,

For welding seam recognition, take a look at MEL Laser Sensors. They have been solving this kind of applications for years.
See also:
http://www.melsensor.com/