Conveyor Tracking, trouble with accuracy when conveyor ramping up.

Robot Controller
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1

Hey everyone!

At work I’ve got a packing line with 14 Robots using conveyor tracking to put details inside a carton.

I’ve got som issues with the accuracy when the conveyor is ramping up or down.
The most inaccurate positioning happens when the conveyor is standing still with the object at the position just before the “WaitWObj wobjcnv1\RelDist:=nDropDelay;” becomes true and the conveyor then starts so that the Robot is connecting and working with the conveyor during the ramp up.

I’ve tried changing the parameters in “Configuration–>Process–>Conveyor Systems” and “Configuration–>IO–>Fieldbus Command” but I don’t achieve the result and accuracy I want.

The conveyor goes from standing still to 34m/min (which is full speed) on approximately 3 seconds.

12 of the Roboats are “IRB - 6650/3.2-125 Type B”, 2 are “IRB - 1600-7/1.45 Type A” and all use the DSQC d377A unit for tracking.
Attached you can see the current settings of a IRB - 6650/3.2-125 Type B.

Does anyone have good knowledge on how to adjust the settings, I guess Start and Stop Ramp, Acc Dependent Filter Value, Sync Filter Settings and Adjustment Accel are the most interesting ones, so that they match both the Robot Modell and the conveyor speed and ramp data?

Many thanks in advance!

// Joakim.

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2

There is a chapter in the conveyor tracking manual on accelerating conveyors - do you have a copy?

3

@graemepaulin

Yes, I’ve read it. :slight_smile:

But I don’t fully understand how to adjust the values so that they correspond correctly to the conveyor speed and ramp.
For example what is meant with “samples” in Start and Stop Ramp, how do I match the Adjustment accel (in mm/s2) and Acc dependent filter (in m/s2) and how do I best match syncfilter ratio according to Robot Modell and Conveyor speed/ramp.

I’ve tried changing them back and forth, but the inaccurace still remains.

// Joakim.

4

The acceleration profile (UseAccProfile command) would be the place I would start - this will match the tracking to the acceleration/deceleration of the conveyor.

The profile only has basic arguments - no need to play with the other parameters mentioned in the chapter.