Smoothly changing velocity profile

    Hi everyone,

    I have a KUKA KR22R1610_2 C4 with KSS 8.6.8

    I am first defining a path, and then I need to make the velocity change smoothly along that path, as a function of the position on the path. The path may be defined with many points close together.

    I have used LIN with $C_DIST to overlap velocity profiles between short distance points. However when points are not colinear, the velocity drops at the corner.

    So now I am trying with splines. Or maybe there is a better way to do this?

    Thank you all in advance!

    Velocity drop in corners is driven by inertia and servo maxima, not by LIN vs SLIN. SLIN is better at pre-plotting the path, but doesn't miraculously make the corner problem vanish.

    For controlling speed, the quick&dirty approach might be to adjust $OV_APPL at every point, probably using Triggers. Controlling $VEL.CP and $VEL.ORI in a similar fashion would be another option, although I don't know Spline motion well enough to be say how well it would work for SLINs.

    If you need more precise control over distance, you might have your Triggers in the Robot Interpreter program set "goals" for velocity, then have the SPS perform some sort of controlled curve or ramp in the background to transition from the current velocity to the goal velocity.

    Quote from SkyeFire

    Velocity drop in corners is driven by inertia and servo maxima, not by LIN vs SLIN. SLIN is better at pre-plotting the path, but doesn't miraculously make the corner problem vanish.

    I am working with KUKA officelite and SIM PRO, and in simulation when using C_DIS there is a clear difference between using LIN and SLIN, as SLIN is able to mantain constant velocity, the problem I have with SLIN is that the velocity profile is not so easy to control and is difficult to vary the velocity as a function of the path.

    If you want to vary the speed on a preplanned path from the programmed velocity, the best way is to use $VEL_APPL. Which can limit the speed but not set it above programmed. You can couple this with whatever you like. Set vel_appl in relation to relative humidity of the room, distance to the next point, gluegun temperature, chromodynamic pancake batter mixture density,..., etc. You get the point.

    $VEL_APPL should be available from kss 8.6

    The other way is to hack with $OV variables which sucks. And i think most agree. But most people have done it at some point with various degrees of anguish, shame and regret.

    The last way would be to use the not so much documented kuka function generator (dont remember the name) but you can find manuals and info on it thru this forum.

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