Robot Position Inconsistancy & Mountplate Geometrical Inaccuracy

General Questions
1

Hi everyone.

First of all i’m using VC 4.1.1 Essentials.

The title might not be enough explicit so let me explain the problem i’m facing with more details.

  1. I've noticed that for some robots (I obviously havent tested the whole eCat) the tool frame is off the geometrical center of the mountplate. the values are expressed in the object reference, the object being the tool frame. (I select the tool frame in Origin mode and then i select the geometrical center in edge mode) Hereunder a few examples:
<p style="text-align: center;">UR10 FlangeUNIVERSAL ROBOTS UR 10</p> <p style="text-align: center;">FANUC PM 200iA5L</p> <p style="text-align: center;">KUKA KR10 KUKA KR10</p> <p style="text-align: center;">KUKA IIWAKUKA IIWA</p> As you can see, only the IIWA is correct. It makes me think that the measurement method is correct. But I dont get what is the problem for the other robots.
  1. I’ve also noticed that when I move my robot to a teached point, it doesnt actually reaches the EXACT location of it:

My first thought was that VC took into account the repeatability of the robot, but the UR10 has a repeatability ok +/- 0.1mm

 

 

This is pretty annoying, and i dont get why i have this kind of behavior.

The first point can really be harmfull using VC as an engineering software.

 

My general question is to know if I am the only one facing the issue ?

 

Thanks §

 

2

No, you are not alone. When doing a snap, please remember to validate your measurements before post-processing. For example, you might get 498.567 instead of 500mm, and so on. So in cases where you need high accuracy, it helps to know what dimensions you are working with and to check the XYZ values after a snap.

This also applies to translations and rotations where you use a displayed grid with marks to incremental value as well as where you hold down shift to select a geometry and use that to select a value for the translation movement.