Kuka DKP400 positioner

[pmrichardson4]

Hello!

I am attempting to learn how to synchronize control of a KR60 and the DKP400 positioner in preparation for the arrival of these machines. I have installed the latest version of Kuka prc but the positioner is not showing up in my Virtual Robot subcategory. I have been told that this machine is included in the library, any ideas as to what the problem may be?

Thank you!

**UPDATE
I resolved the issue, I had not licensed my version properly!

[Johannes @ Robots in Architecture]

Hello,

Great to hear that you were able to sort out the problem - only the full member version supports external axes.
According to your data you're with UTexas, right? I've unlocked your account as a member account so you can download up to date versions of KUKA|prc and get access to the Rob|Arch eBooks.
The DKP400 can be a bit tricky sometimes, let me know in case you need any help.

Best,
Johannes

[pmrichardson4]

Johannes,

Yes I am with UTexas! Myself and another student, Ben Wilde, are working with Ben Rice on preparing for the robots to arrive. Thanks for unlocking my account.

I do have another question about the DKP400. By replacing it in your turntable example file, we have gotten it to successfully rotate, but we cannot figure out how to modify the tilt? Any help would be much appreciated.

Thanks!
Phil

[Johannes @ Robots in Architecture]

Hello Phil,

Say hello to Ben to me!
By default, the tilting axis should be the external axis after the rotation, i.e. if the rotation is E1, then tilting will be E2. If you've got a linear axis attached before that, E1 becomes E2 etc.
You can right-click any movement component in KUKA|prc and enable the external axis inputs with E1 to E4 to manually set them. The automated solver works can sometimes do funny calculations with the tilting axis - but you will see it in the simulation anyway!

Best,
Johannes

[pmrichardson4]

Johannes,

Thanks for the response, that information was very helpful and I've now got a simulation mostly working with the rotation of the positioner. However, when I add in the tilt axis (E2) for one of my point-to-point movements, the tilt of the positioner breaks the path and extent constantly because it keeps tilting too far. Is there a way to constrain the tilt to only go from 0 to -45 degrees?

Also, is there a way in a Pick and Place type of setup to have the Pick-Up Point stay stationary while the Target Points rotate on the positioner?

If you could have a look at the GH file I attached any tips would be much appreciated!

Thanks

[Johannes @ Robots in Architecture]

Hello,

Ah, there is a misunderstanding there - the E1 to E4 values are angles, not points. At the moment, Grasshopper is turning the point coordinates into numbers, probably by first casting it as a vector and then calculating the length of the vector.
That is why it's looking systematic, but strange :)
Basically you have to think of some kind of formula that adjusts the tilting of the table, which may involve some trigonometry. Alternatively you can look into the automated solver.
Note that if you are picking something up from outside the turntable, you have to manually set the E1/E2 value so that this position is always constant. If you set coordinates manually, that will override the automatic solver.

In order to help you a bit more, it would be helpful to have a better idea what you are trying to achieve. Please send it via eMail if you don't want it to be publicly online.

Best,
Johannes

[pmrichardson4]

Johannes,

In this case, we are simply trying to create a simulation that coordinates the positioner's rotation and tilt to optimize the toolpaths. This first test was using the example of a pick and place setup to attempt to pick up a point, rotate and tilt the positioner, and then move to each target point.

In the example Turntable file, you set up the automatic rotation of the positioner by adjusting the dynamic value of the x vector under the rotary axis external kinematics to -1 (see attached). If I were to want this automatic solver to account for positioner tilt as well, what dynamic values would I need to use for these vectors? Am I correct in thinking that this is the automatic solver you are referring to?

[Johannes @ Robots in Architecture]

Hello,

I believe that the automated solver should work with tilt by default as well - otherwise you can quite easily calculate that yourself, basically get the vector you are interested in, calculate the angle to the how it should align in the plane of the tilting table, and then use it as the input (or possible the inverse, depending on what you want to achieve).
As I mentioned before, you can also send me a file via eMail and I can look into it.

Best,
Johannes

[pmrichardson4]

Hello Johannes,

We've been experimenting with the positioner and arm coordination quite a bit and have gotten some nice results. I have another question regarding the positioner in preparation for their approaching arrival.

Is there a way to change the location of the positioner? I see that by default when using the positioner, the z-axis zero is defined as the top of the positioner, but is there a way to change this so that the z-axis zero is at the bottom? I am trying to get the positioner+robot CORE component and another robot CORE component to sit at the same z position in Rhino (sit on a floor).

Thanks!

UPDATE: figured out how to move the positioner, never mind!

[Johannes @ Robots in Architecture]

Awesome, glad to read that you got it to work! I was away the past days and somehow missed the post.

Best,
Johannes

[sialam]

Hi Johannes its been quite some time since we had a word. This time I am here with Daniel writing to catch up with you on what we have been doing for the past weeks.

First, Daniel went out to Toronto to have a KUKA retraining on programing 1 & 2 as his experience was with ABB robots. Everything went well and he seems to feel more comfortable and knowledgeable of tiny but important details.

We installed the chuck, did the calibrations that were not as accurate and mounted the scanned pipe in place in order to do a dry run. Here I am sharing a tiny bit of the first dry run where the error of the e2 axis appeared (Maximum Following Error Exceeded) , I believe it is regarding the bigger load on the E2 axis.https://www.youtube.com/watch?v=BFUUn94hGnQ Nothing fancy but we try to record as much as possible.

We are characterizing our laser beam with a beam profiler in order for us to compute the catchment efficiency and the correct cladding parameters.

I was wondering if there is a possibility to add another angle configuration with the existing code or would we have to add some code in the script that you made. We want to add another degree of configuration to our beam for more catchment efficiency. We might start to dig into this possibility inside the code but we where wondering if you could help us with a 30 min or so session in order for us to understand better the workflow and the script.

I hope this is not to much to ask, but we would also like to learn a bit more in depth.

Also find attached a few images of the setup that we will run just for reference.

We hope things are getting back to normal and you are safe and sound. Sorry for the very very late response.
Syed & Daniel

[Johannes @ Robots in Architecture]

Hello Syed & Daniel,
Thanks for sharing the nice photos and videos! The following-error is rather strange as the DKP-400 can do 400kg payload as per its name. Maybe there is something mechanical in the way? Or is your metal piece that heavy?
And sure, we can schedule a quick call, it might just end up at the week after Easter as I'm busy with an ICRA paper this week and next week our daycare is on holiday. Please send me an eMail so that we can schedule something!
Best,
Johannes

[sialam]

Hi Johannes
We are taking a look at our Trace files in order to solve the issue we have with the positioner.

In the mean time Daniel took the workshop for System Integrator from kuka last week. We actually learned to do this there so it was pretty positive to have taken the workshop. During the workshop Daniel met Jean-Nicholas from Hooke Park, I bet you have heard from him, his work with wood is awesome and we are more than excited about Kuka prc and its different possible applications, we are very happy we chose it.

On the other hand we just received lots of pipes for starting our laser characterization and selection of cladding parameters, unfortunately a piece on our cladding head needs to be changed since there is a heating element because the laser is overshooting, this should be an easy fix as long as we receive the part. (refer to the images to see the problem) We realized that while we where using our profilometer to characterize our laser, so we have to stop all our tests. Nevertheless the laser beam looks good (from what we could see) and we hope to soon have the right cladding parameters for our test that we for sure will share here.

We scanned one of our pipes and we will now use this new scan for the cladding program you have seen.

We'll contact you and hope all this info serves for anyone around using similar setups.
Thanks!!

Syed