How to import ,...

Started by happytriger2000, October 14, 2014, 03:18:27 PM

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happytriger2000

Hi,
    I would like to import the Gh components in this picture:


to this gh file:


I tried to align the gripper in picture 2, but the robot is in an awkward position so to straighten up the robot by using the slider for each axis in file 02_PRCIntro_AxisMovement - KR200-2-test.gh, open attachment.

Johannes @ Robots in Architecture

Hello,

You rather overcompensated by putting in rather arbitrary values in the tool settings and the moving the tool in space. I've fixed the file, take a look at the attachments.
Basically, it's important to remember that there are several ways how to calibrate a tool, especially in regards which tool axis is used (by default X).
So for now I've put the Tool Center Point (TCP) of the gripper to the global origin with X being the tool axis. As the tool is normal to the flange, B=-90, and A and C = 0.
The TCP is 255mm away from the flange, and if you take a look at the KUKA manual or the custom tool illustration, the axis normal to the flange is Z. Therefore, Z=255 and X and Y = 0.
One more important thing: You set the tool nr 0 for the tool - this is a very bad idea, as the tool 0 should be the flange (I'm personally unsure if you can even change it easily) with 0/0/0/0/0/0 for XYZABC. Set the same number and same values as you got when you calibrated the gripper at the robot. If you really got X=-1390, Y=430, and Z=-2180 for the tool, I'm quite sure that there is some error - that tool center point would be somewhere near the robots root point.

Hope this helps!

Best,
Johannes @ Robots in Architecture

happytriger2000

Thanks.
How do you set the TCP for the tool?

Johannes @ Robots in Architecture

KUKA|prc assumes the TCP of a custom tool geometry to be at the global origin of Rhino. On the robot you have to calibrate the tool to get the right XYZ and ABC values. The KUKA manual guides you through all the calibration steps (e.g. first get the right XYZ offset from the flange via "XYZ-4 Point" and then the ABC values via "ABC World").

Best,
Johannes @ Robots in Architecture

happytriger2000

Actually I meant, how did you map the cplane to the gripper's flat end?
Set cplane--->3points---> from here how do you set the 3 point for the gripper since the gripper is greyed out?


About the TCP, would have to add a new tool:

Johannes @ Robots in Architecture

Hello,

With global origin I'm referring to the actual global origin of Rhino, not that of an arbitrary construction plane.
Just move the gripper manually to the global origin of Rhino, as I did in the modified file. When looking at your screenshot, the gripper seems more or less in the right position. I think I set the TCP of the gripper to the back of its clamps, if you want it to be at the front of the clamps, just move the gripper geometry and adjust the Z-value accordingly (i.e. measure the distance between zero point and the flange-mounting point of the gripper).

Best,
Johannes @ Robots in Architecture

happytriger2000

Ah ok, global origin got it. I move the gripper's flat end towards the WCS manually, is there a more accurate way of doing this?
http://youtu.be/XIo0dtAxDNc
Also, how do I temporary hide the grey robot?

what do you call the gripper in this picture:




Johannes @ Robots in Architecture

Hello,

Well, the tool is as accurate as you draw it - you can of course e.g. constructively find the accurate TCP, or even work backwards from the XYZABC values you got when you calibrated the tool on the robot.
On the other hand, a simulation is never going to be 100% accurate anyway, as also the physical robot is probably not 100% identical to the public 3D model, with some additional, internal calibration data ensuring accuracy on a "real" robot..

In the image, the mesh geometry that you have at the global origin is basically the source geometry for the tool (you can hide it in Rhino). It is then moved to the right position according to the robot's axis values and the tool's XYZABC values.

Hiding the robot works as with any Grasshopper component, i.e. right-click and disable preview.

Best,
Johannes @ Robots in Architecture

anaisac40

#8
Quote from: Johannes @ Robots in Architecture on October 14, 2014, 04:45:32 PM
KUKA|prc assumes the TCP of a custom tool geometry to be at the global origin of Rhino. On the robot you have to calibrate the tool to get the right XYZ and ABC values. The KUKA manual guides you through all the calibration steps (e.g. first get the right XYZ offset from the flange via "XYZ-4 Point" and then the ABC values via "ABC World").

Best,
Johannes @ Robots in Architecture

It's always difficult to find this kind of tutorial and what you have just published is timely .