Wrongly measured position after collision.

    Hey!
    Dear Robot-Masters, I need Your help. I've got some unusual problem with LR Mate 200iD.


    After collision - force was put with 20mm offset from the 6th axis, parallel to it (robot tried to insert the workpiece into the socket with other workpiece in it) - robot was about 10 deg pitched, but after alarm reset it starts to move normally. Whet it tried to take another workpiece I realised that end effector has now about 1,5mm offset (angles are ok). I've measured TCP and UFs again. User Frames origin points moved 3-4mm in X and Y axies. UTool offset in X axis changed weirdly from 0.03mm to 1.5mm. When I tried to spin the tool, probe tip starts to make circles, so I put X offset back to 0.03mm, and it was again spins as it should.

    I've measured UFrames again with "properly" working TCP. There still was a 2-3mm difference to the previous settings. When I checked the extreme positions, I realised that they don't agree.


    Previously, when robot was working fine, measures of holes for dowels pins had an error of 0.05mm for distances and 0.1 deg for XY angle. Now it's about 0.5deg error, and what's more, 0.5mm error in X axis and 1.7mm in Y axis...


    I've made an experiment - I set 180mm on a calliper (with 0.01mm accuracy) and moved the robot along the calliper in X and Y axies. In both directions robot has a huge error. In X axis it was about 0.7mm but in Y axies end tip exceeds about 1.4mm...



    Have You any idea what should I do?
    I set PR to zeros in joints, and jog robot to it, but the mastering stripes on every axies seems to align well...


    Should I master it anyway?
    Jog the robot to home/perch position and retrive it from image or AOA?

    Should I make an image in zeros from Roboguide and retrive it from this image in zeros?

    Thank You, for your answers!

    @jmd2777

    Robot stand did not move. I would feel it, when I was checking the mastering stripes.



    @Lemster68

    You're right, that's how it worked for me with other robots till now. But this case is much different and strange. Measured TCP moved by 1,5mm in X axis, but when I jog it according to Tool frame this offset gives me a huge error. Tool starts to move correctly, when I reduse the X offset almost to 0, like it was previous. It looks more like the robot starts to wrongly measure it's possition. Maybe the axies slipped a bit, but it still don't respond the answer "why it overrun the given distance". As I written in the topic, when I moved to joints's zeros by PR, the alignt looked ok. To be honest the gap between the stipes on each joint, greatly prevent from accurate examination.



    @HawkME

    Hope it's not a mechanical damage. Is it hard to examine those harmonic reducers?

    Shouldn't this case give other symptoms like strange noises, shuttering during move?

    Quote from STRAW

    @HawkME

    Hope it's not a mechanical damage. Is it hard to examine those harmonic reducers?

    Shouldn't this case give other symptoms like strange noises, shuttering during move?

    Harminic reducers in such a small robot are also small - so giving enough force it's possible to brake it.

    When moving with the specific axes (JOINT, one after another) if any is broken, you should hear some noises, feel it shakes - put you hand on the robot and you should feel it.

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