KSS 8.x: C_DIS vs C_PTP

    Quote from panic mode

    PTP type motions support CDIS and CPTP

    CP type motions support CDIS,CVEL,CORI


    motion instructions support up to two such parameters and will respond to whichever happens to be the first one encountered along the path.

    The supported types are well documented, no questions there, can you elaborate a bit more on "and will respond to whichever happens to be the first one encountered along the path."


    What I observed is that around the approximated point during a PTP>LIN move the approximation uses two $APO parameters for both CPTP and CDIS I have attached some ss from KUKA.Sim: it goes CPTP 100/CDIS 100

    to be honest i only did limited tests a while ago so this largely based on information obtained.

    exact location of decision making point (to approximate or not) will depend on used parameter and value. usually CDIS is discussed as an example since it is easiest to plot (velocity or orientation are not as intuitive to interpret from graphs).

    but once decision is made, robot will either stay on programmed path to target point OR it will take shortcut using approximated path.

    so once the decision is made, robot is committed to stay on THAT course and that's it.

    when two approximations are used on same point, each of them (if used on their own) would have own "decision point" and most likely they will not be the exact same point for both of them. as robot is moving along the path, the first decision making point encountered that switches path to approximated is the one that wins. when robot reaches second decision making point (for velocity or whatever),, it is already too late to consider it - robot is already on one approximation segment...

    also the working term here is "approximated path segment". in other words, yes, there will be "some sort" of blending and sure it will be repeatable for same conditions but its unclear how exactly the trajectory is computed - there is no published function to use and compute and compare outcome with actual motion.

    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

    Thanks 1
    Quote from Fubini

    Re: KSS 8.x: C_DIS vs C_PTP


    Here is a table I posted quite a while ago when which criteria is used. Maybe this helps.


    Fubini

    It does help, so does the post afterwards, which I have read but just know figured out after I have come to the same conclusion. Just a shame it is not well documented. I will get someone who speaks German better than me to double check the table just in case I read something wildly wrong.


    panic mode Sure the function is not published. OL can be used with KUKA.Sim to compare trajectories and see what is generated to some extend, but surely the parameters of approximation must and can be explained better in the documentation.

    i agree, in fact there are quite few things that could and should be explained. hardly day does go by without finding something new.

    and it is not that KUKA is not trying, there is just a lot of things to manage. so i am trying not to be a pebble in the shoe :smiling_face:

    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

    Just to give you a little perspective being at KUKA for about 15 years: essentially there are about 5 people writing all these documentation for the robot controller and about 100+ technology packages. So it is a lot of work. And to be honest all of those documentation people I ever met where really dedicated. Something you can definitely not say for any KUKA section.

    i am no longer with KUKA but always loved trips to Augsburg and meeting KUKA team. Lots of really good people there...

    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

    Fubini Thanks for the info. That is a lot of documentation for 5 people... You spent 15 years there, nice. I gather you were working on KRL development or control systems by your deep knowledge of the internals.

    panic mode I didn't realize you were with KUKA at some point - KUKA USA I presume. I was certain for fubini, just not for yourself. In which general part of the company if you don't mind me asking?

    Edited once, last by dexterv ().

    You guessed correct. I was working in realtime system being with others responsible on what happens there when you e.g. program a ptp. But I left early this year 😁. Still I probably would not mind returning someday.

    Hi Sir!


    When i teaching one Point Motion. I see that this code Point shown on Work Visual like:

    ;FOLD LIN PLAU5 CONT Vel=2 m/s CPDAT1 Tool[14]:t_Tool0 Base[14]:b_Base0 extTCP;%{PE}%R 8.3.48,%MKUKATPBASIS,%CMOVE,%VLIN,%P 1:LIN, 2:PLAU5, 3:C_DIS C_DIS, 5:2, 7:CPDAT1


    $BWDSTART=FALSE


    LDAT_ACT=LCPDAT1


    FDAT_ACT=FPLAU5


    BAS(#CP_PARAMS,2)


    LIN XPLAU5 C_DIS C_DIS


    ;ENDFOLD

    And I dont understand about the mean of suffixes "C_DIS" C_DIS" in LIN XPLAU5 C_DIS C_DIS?

    Another one

    ;FOLD PTP PLAU4 CONT Vel=100 % PDAT5 Tool[14]:t_Tool0 Base[14]:b_Base0 extTCP;%{PE}%R 8.3.48,%MKUKATPBASIS,%CMOVE,%VPTP,%P 1:PTP, 2:PLAU4, 3:C_DIS, 5:100, 7:PDAT5


    $BWDSTART=FALSE


    PDAT_ACT=PPDAT5


    FDAT_ACT=FPLAU4


    BAS(#PTP_PARAMS,100)


    PTP XPLAU4 C_DIS


    ;ENDFOLD


    What is different with suffies C_DIS and C_DIS, C_DIS above?

    Thanks Sir!

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