Accurate part pick up

    Hello, total newbie here

    We are wanting to set up an arm here for machine tending. We have a Fanuc 2d iRvision camera that we plan to use to locate the parts.

    We are working with round aluminum castings here that have imperfections on the faces, so they do not necessarily sit quite flat especially if they are stacked.

    What is the best way to compensate for that. I see Schunk for example, sells compensation units. Is that the correct direction for me to look into, or is there something else I should be looking at.

    Any info is helpful, thanks.

    Your vision is going to have a limit on how accurately it can measure anything, and rough castings are particularly bad. You'll need to determine the error range of your camera vs the castings, then design your end effector to allow for that much inaccuracy. Grippers that have extra open/close range, for example, and maybe with grip-force or full-range feedback instead of simple open/close sensors, for example.

    In addition to that, 2D vision only gives X,Y, and Rz corrections. So your casting that don't sit level will have Rx and Ry variance that your gripper will have to tolerate. This can be done multiple ways -- for example, an array of vacuum cups with deep bellows is one of the simplest solutions. If that's not workable, it becomes a question of how your gripper engages the casting. If you're just gripping it from the sides, then the tilt might be irrelevant (depending on if you need to correct for the tilt before (I assume) placing the casting into the milling machine). If not, this becomes a question of which surface of the casting you're trying to align the robot to. If the top surface, then you could use Force-Torque sensing. Or, I've seen setups that used three long-stroke "plunger" sensors arranged in a circle, and as they made contact with the top of the part, did trigonometry to calculate a corrective rotation until all three sensors had the same reading.

    Quote from TygerDawg

    Does "machine tending" mean "machine tool load & unload"?

    It means robot is attendant and as such is attending to machine needs in order to keep machine running. normally this means loading/unloading but it could be something else like cleaning, swapping tooling or nesting, probing/measuring, flipping parts etc. The degree of automation can vary but robot is there to replace human in interacting with the machine.

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

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