Semi-Automatic teaching

Hi there,

This is my first topic. I've found many valuable solutions on this forum by the past. But no clues for this one :

I'm working with a KR500-2MT / KRC2 / KSS5.6 and a home made turntable (for stone milling).
I need to improve the calibration of the turn table, that is to find its rotation axis regarding $world.

For several reasons this is the method I want to use :

1) place a fixed spike on the table. The spike head describes a circle around the turn table axis when the table turns.
2) record the position of the head of the spike by touching it (manual jog) with a properly calibrated spike mounted on my robot arm ($POS_ACT)
3) do that for several angles along a full turn (more points => greater accuracy)
4) fit the best circle through the measured points (least square method)
5) from the circle, deduce the turn table center and axis

My concern is that I need to touche and record a good bunch of points to increase the accuracy (10/20). I know how to get "almost" from one position to the next one (it is just a matter of rotation in the table basis). I have already written a program so that the robot arm follows the spike from position to position.

My question is how can I pause my program at each step, then manually jog the robot so the two spikes touch each others, then save the teach position by reading $POS_ACT, then return to the automatic execution of the program that will move table and robot to the (almost) next position, ... ??

Thanks,
Lionel

$BASE is set to the actual base of the turn table
stepAngle = 360.0/20.0
turnTable = {A1 0, A2 0, A3 0, A4 0, A5 0, A6 0, E1 0, E2 0}
turnTable.E2 = stepAngle ; E2 si for the turn table, E1 for a linear track
Rotation = {X 0, Y 0, Z 0, A 0, B 0, C 0}
Rotation.A = stepAngle
FOR i=1 TO 20 STEP 1


    WAIT FOR $IN[1] ; Here I need to do the teaching by manually joging the arm. How ? I'm triggering the next step by pressing a push button to leave the wait instruction


    ; we have left the wait : we recorde the $POS_ACT
    PTS[i] = $POS_ACT


    ; escape the spike head by moving up 50mm
    LIN_REL {Z 50}


    ; turn the table by +stepAngle
    PTP_REL turnTable ;


    ; Move the arm by rotating the TCP by +stepAngle but keep the previous orientation
    RPT = Rotation:$POS_ACT ; 
    RPT.A = $POS_ACT.A 
    RPT.B = $POS_ACT.B
    RPT.C = $POS_ACT.C
    LIN RPT
ENDFOR


PTP HOME
END

Thank you both for your advice,

I was already sticking to a unique TCP orientation but its good to have a confirmation that this is the right thing to do.
To answer to my own question (how to switch from a programmed motion to manual jogging in the same program in order to touchup my spike in T1 mode) I simply place a dummy LIN move after a HALT. I stop on this line (step by step execution, then jog, then store the new position by cling on "save pos", then continue to the next point and the actual position is saved in PTS[i] :

turnTable = {A1 0, A2 0, A3 0, A4 0, A5 0, A6 0, E1 0, E2 0}
turnTable.E2 = stepAngle
Rotation = {X 0, Y 0, Z 0, A 0, B 0, C 0}
Rotation.A = stepAngle
FOR i=1 TO stepNum STEP 1


    HALT
    ; Dummy line instruction. Here go about 5mm down to touch the spike again. Adjust X/Y/Z manually. Clic on save position and continu the program.
    LIN {X 0, Y 0, Z 500}


    ; store the touchup position in .dat
    PTS[i] = $POS_ACT


    ; move the arm slightly away from TCP
    LIN_REL {Z 5}


    ; turn the table by +stepAngle
    PTP_REL turnTable ;


    ; turn the TCP by +stepAngle while keeping the orientation
    RPT = Rotation:$POS_ACT ; 
    RPT.A = $POS_ACT.A 
    RPT.B = $POS_ACT.B
    RPT.C = $POS_ACT.C
    LIN RPT
ENDFOR

panic mode : I'm doing this because in the kuka procedure you need a built-in spike on your table so you know precisely $ET2_TPINFL. This is not my case as it's a home made table for very heavy loads. Moreover I will touch 10/20 times my spike to reduce the error. I will also do that at two levels (z=0.5m and Z = 2.0m).