Post collision movement

    Hi we ve krc4 with kr8. it's our first kuka application and we ve a problem.
    The robot is programmed to hold the product and place it to template but sometimes the product is defective so robot can't fit the product to template and crash to template then it stops and gives an error message about axis 5 torque. Then operator has to get the robot to T1 mode and recall the program again. We dont want it. Instead of giving error, we want to leave the defective product and continue from next step. Is it possible ? How can i do that ?

    My english is not good i hope i can explain my situation.

    [size=2]So your cycle time is 20sec per part...That sounds like... a lot!![/size]

    [size=2]What is the difference between good and bad part? How about nest where part is placed? [/size]
    [size=2]Any pictures?[/size]

    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

    There is no simple way to solve this problem.

    The best solution is to inspect the parts before placing them in the tooling, and detect the defective parts before the collision occurs. Depending on the nature of the defect, you might be able to do this with a simple sensor, or it might require a full vision system.

    The issue is, the robot is "blind." It has no real way to detect a defect until the collision occurs. It might be possible to program the robot to terminate the transfer early, on detection of A5 torque, and drop the defective part before the fatal torque error occurs, but this would require skilled and careful KRL programming. It is also hard to do this kind of sensing action when running the robot at maximum speed.

    Quote from SkyeFire


    There is no simple way to solve this problem.

    The best solution is to inspect the parts before placing them in the tooling, and detect the defective parts before the collision occurs. Depending on the nature of the defect, you might be able to do this with a simple sensor, or it might require a full vision system.

    The issue is, the robot is "blind." It has no real way to detect a defect until the collision occurs. It might be possible to program the robot to terminate the transfer early, on detection of A5 torque, and drop the defective part before the fatal torque error occurs, but this would require skilled and careful KRL programming. It is also hard to do this kind of sensing action when running the robot at maximum speed.

    How i can detect a5 torque and take action for this torque value ? Cycle time is not problem for this application so robot is working in %10 speed. Its a tube bending process. Some tubes are circular form is defective. Can u give me an example for read torque value and take a action for this torque value ?

    Well, you might be able to use Torque Monitoring, which involves "teaching" the robot what the acceptable torque values are for a given program path. This is detailed in the manuals.

    For just monitoring A5 torque... well, you can look up "torque mode" in the manual, but that may not be workable for a pipe-bending application.

    To simply monitor an axis torque and branch the program before the system fault occurs, you could set up an interrupt to monitor $TORQUE_AXIS_ACT. The details would depend on your application, but a very simple example would be to create an interrupt that would be triggered by $TORQUE_AXIS_ACT[5] exceeding a certain value (which would have to be determined experimentally). The Interrupt routine would then have to top the robot and terminate the motion using BRAKE and RESUME. The hard part would be determining a safe action for the robot to perform next -- in a pipe-bending application, this error could happen at any point during the motion, so creating a safe "escape" path for the robot could be difficult.

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