Issues when optimizing tool path and plane orientation

[alvarogarciasab]

Hello all,

I wanted to take this message to share some stuff that I was working on.
I am validating that a Kuka KR210 R3100 ultra will be able to reach the overall perimeter of a worktable to cut material through a spindle + saw blade.

The point is that I almost checked that the robot is able to achieve the farest points and not exceed the angle ranges.

Even this, the last linear movement is not correct because it exceeds the A6 angle range.

I was wondering how to optimize movements. I am pretty sure that there is a simple thing. I have not too much experience on this.

Thank you in advance 

[Johannes @ Robots in Architecture]

Hello,

Sorry for the very late reply, I somehow missed your post!
Regarding your post, the challenge is that while the robot can individually reach every position, A6 winds itself up.
There is no immediate, easy fix as it you are covering a large range of movement.
I would approach that from the order of movements, because if you are e.g. continuously incrementing A6 (you see the A6 value go up from 20 to 600 which is out of range), you could instead set the start position to -340 degrees, then the 600 degrees before would be 260, which is inside the range of the robot.
Or instead try to arrange that so that every movement with a "positive" effect on A6 is followed by a "negative" movement.

The "ultimate" solution would be to simply set the A6 to infinite rotation, which is possible, however you run a high risk of damaging the cables of your endeffector if you wind it up too much. I generally try to avoid that for "powered" tools.

Best,
Johannes

[alvarogarciasab]

Hello Johannes!

Thank you so much for your reply.

The infinite rotation would be a great solution but I have just purchased the robot with the default configuration.

Regarding the continuous incrementing A6, I guess that there is something that I am missing out on.
It is weird because if I set a -179 o -187 plane rotation for the last linear movement, it works ok. But it's when I set -180º when the warning appears. Does it make sense?
I have tried not to accumulate positive rotation in A6 to be inside the range.

Another solution has been to change the command order.

I would like to know whether there is some bug or there is something that I am not understanding.

I really appreciate any help you can provide.

[alvarogarciasab]

Some screenshots.

Best regards,

[Johannes @ Robots in Architecture]

Hello,

Unfortunately I cannot really read anything out of the screenshots, maybe you could attach two files to compare?
There is one bug with the command sequence, you could run the "Solution Recompute" (hotkey F5) and see if the result changes. That will be fixed in the next release, though.

Best,
Johannes

[Matty Fuller]

If the robot is capable of completing each individual cut without winding up A6, but not the entire program, then this should be easily solved by unwinding between cuts. This would be done by setting a neutral position above the work table and commanding specific axis values (ie: A6 = 0) rather than allowing the robot to solve for a cartesian position.

[singline]

sure, you could also test changing the TURN variable to turn axis 6 in the alternative, less efficient direction to avoid maxing out the axis.