KR6-2 (KR15-2) mastering, should A2 be at -90 or 0?

    I have been setting up a KRC2 with a KR6-2 (the one that is the smaller model of the KR15-2). We are in the process of setting up RoboDK to simulate our system in our lab, I have created a robot model in RoboDK and defined the kinematics as per the details outlined on the product specification (for example A2 -55 to +115 and the home position I would expect to be 0 deg). I however can not seem to find a config for this robot in the MADA library that matches what I would expect for my hardware.


    The only KR6-2 config appears to be for the more common model of this robot where A2 has a range -155 to +35 and a home position of -90.


    I am running KSS 4.1.7 SP4.0 so I went looking at the other configs for model such as KR2-15, I noted that for this model $MAMES[2]=-90.0 in the machine.dat so clearly I am missing something here as I would have expected this to be 0 if I am reading the specification correctly?


    Maybe I have an odd model of robot or some out of date MADA data on my distribution media? Do I need to source the robots MADA config from somewhere specific or am I making poor assumptions based on the specification data in the KUKA pdf while I'm configuring my RoboDK simulation.


    Any advice to point would be most welcome, regards Ivan

  • Jump to the most helpful post

    • AD

    So my confusion comes from trying to make sense of the following attached specification for my robot. If I understand it correctly then the master for A2 would be 0. (it can't be -90 as that would be out of range)


    If I look at other specifications such as a KR16-2 then is having a A2 master at -90 is logical.


    Now do you see my problem Fubini or have I missed something?

    From the (me)chanical point of view you might be correct. From the (ma)thematical not. MAMES stands for mathematical mechanical shift and is always -90 degrees in kuka robotics. This is kuka convention. Of course in theory you could set it to 0 as well but than a lot of machine data would have to be adapted to reflect this change. Also nearly every program would have to be shifted to reflect this. Finally kuka users are used to it so you should never change it to maintain compatibility. You are only considering the mechanical specification not the software using the mechanic.


    If it is different in the mechanical specification report it to kuka. Maybe a error in documentation. This type of things should not happen but experience tells probably everyone of us it happens. If they really changed this they could tell you as well. Though after more than 15 years experience inside KUKA R&D in the past I seriously doubt that my former team members would change it.


    You could also checkout kuka xpert portal, see forum Read first, to get the latest documentation for your robot and software.


    Fubini

    looking at Panic's RoboDK model it's exactly as I would expect for a KR16-2 and for example the A2 range of motion is per the specification. (my question is does this hold true for say a KR15-2)


    I feel that I have reached the limit of my KUKA product understanding here while trying to reconcile the difference between the specification and what I would expect. I need to fine someone who has experience with the KR6-2 (KR15-2) family of robots so am leaning towards a support call with KUKA regarding this. (it's very confusing that there seems to be various KR6-2 models)


    To get me across the line with my students I am going to fit my RoboDK model to the software switch range of motion that the actual KRC2 is reporting to me and ignore the specification for now. If I discover that I have the wrong MADA config then this may change things.


    • Helpful

    never heard of KR2-15

    have probably seen but do not remember KR15-2

    check MADA for your robot. that is where the info comes from.

    for most robots (specially older ones), MAMES values are {A1 0, A2 -90, A3 +90, A4 0, A5 0, A6 0}

    in recent times there are robots with different MAMES...

    for example Quantec may use something like {A1 -20, A2 -120, A3 +115, A4 0, A5 0, A6 0}

    the agilus KRrR540 has A4 also turned some 90 deg or so.


    whatever the case - read MAMES values in MADA for selected robot...


    btw MAMES only specifies axes values at mastering and nowhere else.


    the example standard Cannon position {A1 0, A2 -90, A3 +90, A4 0, A5 0, A6 0} is used for all (noncollaborative) KUKA robots as a default home. this is also used as a position to mount and reference loads on the robot arm.

    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

    For most KUKAbots, moving all the axes to 0 will stretch the robot arm out horizontally. This presents obvious potential clearance issues. As such, KUKA uses MAMES to offset the Mastering position from the 0 position.

    Quote from Ivanoff

    So my confusion comes from trying to make sense of the following attached specification for my robot. If I understand it correctly then the master for A2 would be 0. (it can't be -90 as that would be out of range)


    If I look at other specifications such as a KR16-2 then is having a A2 master at -90 is logical.


    Now do you see my problem Fubini or have I missed something?

    maybe I need to rephrase my question:


    In regards to the specification attached how do I utilize this information or is it completely unrelated to the configuration of the robot within KSS?

    if you check the pictures from panic mode in post #5


    top picture:

    mathematical 0-position (all axes are set to 0 deg - useful if you want to do a forward kinematics)


    bottom picture:

    mechanical 0-position (for axis2 and axis3 the $MAMES values are set


    as explained in mada:

    REAL $MAMES[12] ;VERSCHIEBUNG ZW. MECH. UND MATH. NULLPUNKT ACHSE[I]

    difference between mechanical and mathematical 0-position


    the pictures in post #7 and #10 are correct


    $MODEL_NAME[]="#KR6_2 C2 FLR ZH01"

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