CHECKING PREVIOUS POSITION AND ADJUSTMENT

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Hello everyone!

I have one question about the robot position. In our company we have three robots that do one identical job, they load machines with some iron pieces, but the pieces are every day different, the exterior looks similar, but the weight can be between 10-50 kg. 

There is a problem with loading, we put the payload value every time, but the position isn't the same on the same job (the same pieces), and as a result, the robot misses the machine chuck center....

Is there any function that we can check the ABB robot's position, and if the position isn't OK, the robot will make adjustments and correct itself into the right position?

Comments

  • mandolas
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    Hi...

    If the load is correct and the movement is "fine", it should always stop in the same position, disregard the wear and mechanics involved.
    A possible solution would be to use the Distance() addition, this would give you the distance between the current CPos() position and the target, if it is greater than your tolerance, move to the target at a slower speed.
    Speed ​​interferes with stopping if the zone is not "fine" and weight variations, even if small, also influence the final position.
    PS: Check the robot's attachment, it may be coming loose.

    Good works.
  • graemepaulin
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    When you say you put in the payload value every time - do you weigh the piece of iron and then input this as the payload?
    Is the tooldata correct (the mass and center of gravity of the tool)?
  • lemster68
    lemster68 ✭✭✭
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    Does this robot have the Absolute Accuracy option and if so, is it activated?
    Lee Justice
  • Petek7222
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    When you say you put in the payload value every time - do you weigh the piece of iron and then input this as the payload?
    Is the tooldata correct (the mass and center of gravity of the tool)?
    Yes, we weigh the piece and put the data to the FlexPendant, but I know that payload value doesn't change the position, it only adjust the amount of energy the robot needs .Tool data is correct.
  • Petek7222
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    lemster68 said:
    Does this robot have the Absolute Accuracy option and if so, is it activated?
    The robot doesn't have Absolute Accuracy option, I am going to investigate that option. Can you maybe describe briefly how this function will help?
  • graemepaulin
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    The accuracy of the load data (payload mass and center of gravity) affects the repeatability of the robot motion.
    How much clearance is there between the metal being loaded and the jaws of the chuck?
    What is the robot type and variant?
    Have you checked if the robot is overloaded? The further the center of gravity of the gripper and payload combined is from the tool flange the lower the mass that the robot is rated for.
  • lemster68
    lemster68 ✭✭✭
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    Absolute accuracy robots undergo a calibration procedure in which the deflection of the robot arm is measured.  The robot then compensates for that deflection under load.
    Lee Justice
  • Petek7222
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    Sorry for the late response. You can see the picture on the link: https://we.tl/t-GKhE02Tv8L. I hope that you can see it.

    Steps:

    1. The robot put a piece in front of the chuck
    2. The robot holds the piece when the tailstock pushes the piece into the chuck. The tailstock must be 99% correct, piece center and tailstock center must be in line. And here we have issues, Y and Z deviate about 1-2-3 mm, it depends, and also rotations.
    3. Chuck/clamps closes
    4. The robot opens the gripper and steps out
    Thank you!