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I need to use GH Python (Python 3 Script) to properly sequence a set of KUKA|prc Commands.

I'm taking input from the PRC components Digital Output, LINear Movement and Wait commands. These are generated by those native Kuka PRC components.

The python is just taking those lists and building a new list with them sequenced as I need. (It's much easier for me in Python than native Grasshopper!)

It builds the list no problem, but when I try to use it as input to the Kuka CORE, I get the error "1. Data conversion failed from Goo to KUKA|prc Command".

So, in Python I need to cast this so it's in the appropriate format.

How do I do that?

Thanks very much for any help!
Mark

Hi, 

I'm starting to do some clay printing on a rotary axis setup using a KR-6 robot, and an external axis (E1), driven by a stepper motor. 

Here's an image of the simulation, which works nicely:



Here's a short video of the robot doing the same toolpath. 

The motion of the robot (A1-A6) is exactly as expected. It is the rotating axis E1 that is out of sync. It seems to lag behind the A1-A6 positions when arriving at new points. 

I'm specifying an E1 position on every LIN move. Here's a typical line of KRL: 
LIN {X 594, Y 210.275, Z 375.91, A -90, B 83.884, C -90, E1 97.954, E2 0, E3 0, E4 0} C_DIS

If the E1 motor is working correctly, can I expect the robot end effector position, and the rotary axis, will always be in sync? That is, the robot will not move to the next position until A1-A6 and E1 have reached their specified positions? 

If that's the case then I know I have an issue with the stepper motor setup perhaps accelerating or decelerating improperly. It's actually fairly close to correct, it's just not perfectly synced. 

Thanks very much for any guidance, 
Mark

Hi,

Our robot setup necessitates specifying all the external axis (E1 through E6). Right now PRC generate E1 through E4 in the code (all 0). But when I run a program it says "Impermissible start motion". The error occurs on this line:

STARTPOSITION - BASE IS 0, TOOL IS 4, SPEED IS 10%, POSITION IS A1 0,A2 -65,A3 78,A4 0,A5 -102,A6 0,E1 0,E2 0,E3 0,E4 0

If I add E5 0, E6 0 at the end it works.

Is there a way for me to generate those extra axes in the code that PRC outputs?

Thanks!
Mark

Hi,

I wanted to log two feature requests (or learn where I may have missed these features in the existing implementation!)

1) A simple checkbox in the UI to allow A6 to not generate an error if it spins beyond the limits. We do this a lot and it confuses students when the Core turns red but the code runs just fine.

2) The ability to read the transformations of each axis at each frame of the simulation. We hacked this using the mesh at each frame and computing the transformation between mesh vertices frame to frame. A more elegant solution would be welcome! I'm using this to allow Fologram to draw the robot simulation in augmented reality.

Hoping these can be considered!

Mark

Hello,

I was doing some tests with motion analysis trying to see different motions using PTP, LIN and SPL commands.
The motion path is a combination of 180 degree in place rotation (in 30 steps)+linear translation+ combination of 360 rotation and translation (in 30 steps).

Using PTP movement:
The simulation performs the path completely without any error or singularity alert.

Using LIN Movement:
The simulation makes a sudden move in the initial part of path (180 in place rotation) also the Core component turn into singularity orange color.

Using SPL Movement:
The simulation makes a sudden move in the initial part of path (180 in place rotation) also the Core component turn into error red color.

Combined movement:
Using PTP movement in the initial part (180 in place rotation) and LIN movement in the second (linear translation) and SPL in the last part. The simulation performs the path completely with out any error or singularity.

Questions:

1_ What does the "sudden rotation" in the simulation in the initial part of the path mean ? is it a singularity that the Core cannot capture ?
2_ Why does PTP work well for the whole path while LIN gives "singularity alert" and SPL "gives out of reach error"?