fanuc r-j3 in singularity

    Hello,

    I have run into an issue with my R-j3 being stuck in singularity. I had this happed about a month ago when I accidentally ran the program that puts all axis at 0. All I had to do to fix that was flip the wrist and I was able to get it working. I know it was working because I ran 2 other programs.


    So without touching it for a month it is back doing the same thing. It is in its programed position where we start all of the programs, and it doesn't want to move. I can jog it obviously, but cannot run any programs. Right now it is sitting at the following location:

    X= 758.149mm

    Y= -531.011mm

    Z= 85.728

    W= -179.218 deg

    P= -0.385 deg

    R= 88.973 deg


    This robot does a lot of sitting around, only gets ran once or twice a year.


    Please let me know if you have any suggestions.

    Thanks!

    Position isn't much use without the current TCP transform, the user frame the point is in, or is active, and what model the arm is.


    Is your first move a linear move that attempts to go through singularity? Is your start point (home) close to a J5 position of 0 degrees?

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    My first move is a joint move, it has been working for the last 5 years. We recently moved this robot though. I can linear, just not joint.


    J5 is not close to 0 degrees.

    Can you post the initial position and position after the first move in joint coordinates?


    You could save the first move position cartesian values then convert to joint to get the values. You could also try moving with the values in joint representation, just do so carefully in teach mode.

    For sure, look at the joint angles when investigating singularities.

    Irrespective of 'working for 5 years' , this has no bearing when a problem is occurring.


    Most singularities occur with JT4/JT5/JT6 combinations, but can also occur with JT2 and JT3 combinations too, so it is imperative to review the joint angles of your current position and probably the joint angles of your intended target position too.


    If in/close to singularity will prevent linear moves not joint manual jogging.

    Kwakisaki, Something would have had to change to cause it to start happening now though right? The robot knows where it is and where its going.


    Thank you! I will look at the joint angles

    Quote from Jfoley410

    Something would have had to change to cause it to start happening now though right?

    Absolutely, you are experiencing an effect, now you need to discover the cause.


    XYZWPR values represent values of how far the end of the tool (TCP) is away from the active coordinate system.

    If it is possible to achieve the same XYZWPR location values, with different joint angles, then there is more than path available to the robot too many paths available result in singularity.


    1.

    Is there anything obvious on the arm itself that doesn't look quite right - like a sticker upside down/dressing harnesses in the wrong position at the position your starting from, or the position you're trying to move to?


    2.

    When you manually move it from start to target at a slow speed, do you see one or more joints suddenly start to accelerate a lot faster, but the end of the tool appears nearly static.

    Got it! just needed to change the first move to joint instead of linear. Also somehow I was calling the actual home position instead of the programed start point.


    Thanks for your help!

    Quote from Nation

    Is your first move a linear move that attempts to go through singularity?

    Quote from Jfoley410

    My first move is a joint move, it has been working for the last 5 years.

    Quote from Jfoley410

    Got it! just needed to change the first move to joint instead of linear.

    You've got to be kidding me...

    Check out the Fanuc position converter I wrote here! Now open source!

    Check out my example Fanuc Ethernet/IP Explicit Messaging program here!

    Haha 2

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