EULER angles to cartesian angles conversion

[scotch99]

Hello.
Does anybody have some kind of converter that convert Euler angles (used in Kawasaki robots) to normal cartesian angles? It's very difficult to define correctly the tool without understanding that EULER angles theory!!!

[Jim Tyrer]

I've always assumed that most manipulators use euler angles for cartesian position rotations, so 'normal cartesian angles' are in fact euler angles.
One can imagine them as being roll, pitch, and yaw of an aircraft, relative to you sitting in it. Roll is rotate about y (Ry), pitch is Rx and yaw is Rz relative to the current frame.
Also remember that a tool frame is 'attached' to the last joint of an arm, that the Z-axis of the tool frame is always coincident to the axis of rotation, and clockwise rotation (according to right-hand-screw-on-thumb-rule) is positive rotation direction.
So tool +Z is (normally) facing away from and perpendicular to the flange, and positive rotation would be counterclockwise when when you eyeball the flange face-on.

[scotch99]

Thank you very much Jim for an explanation but I work a long time with robots and I know how Tool coordinates works. I don't know if you have ever worked with KAWASAKI robots? They are different. Rotations aren't X-Y-Z there are (according to documentation) Z-Y'-Z'' and it's called Euler's O,A,T angles. That's why I'm looking for some converter. Except that normally on "normal" robots axis X of TOOL 0 points downward but on KAWASAKI points to the side!! Also Base coordinates are not the same as on all other robots.

[Jim Tyrer]

No I've never done a Kawa and I am sorry if I have insulted your level of experience.

I have seen cases where the order of euler angles are switched around. According to http://en.wikipedia.org/wiki/Euler_angles there is apparently no official standard, and there are 12 different ways of using them. It's likely a matter of figuring out which one.

[scotch99]

It's OK. I'm just trying to figure out how this sh... works. When I was trying to understand the documentation it was completely different in practice. Maybe somebody has some experience with that kind of EULER coordinates that are used in Kawasaki and can help me.

[kamemasta]

There is a program out there called Trafo. It is the best converter around and will do exactly what you need. If I can find my copy of it I will re-post. Run a search for it and you might find a copy.
E

[Kōkaku kidōtai]

Hi,

I tried to find software you mentioned above - unfortunately  trafo i popular keyword...
No luck in finding it 

If you find it in your 'resources' please be so kind to post it.
 

Best Regards !!!

[Jim Tyrer]

Pehaps you are looking for Klaus Eichele's TRAFO?
http://anorganik.uni-tuebingen.de/klaus/soft/index.php?p=trafo/trafo

[scotch99]

Yes, that's it. But I have no idea how to use this program. Kamemasta can you help me?? Short description HowTo, please??

[Jim Tyrer]

There is also http://code.google.com/p/vrmltoolbox/

[TygerDawg]

I thought the Kawa language (what is it?  "AS" or something like that?) was a derivative of the old Unimation VAL language.  Which begat Adept's V+ language.

If so, then the Euler convention is probably the same.  The points all have the format {X, Y, Z, y, p, r}.  Commonly known as "Yaw-Pitch-Roll", it is described thus:

Yaw = rotates the coordinate frame about its Z-axis
Pitch = rotates the coordiante frame about the new Y-axis
Roll = rotates the coordinate frame about the new Z-Axis

or as my Brit friend used to say "Zed Wye Zed"

[Jim Tyrer]

It's a can of worms once you start poking about.
I have this chart from off the web, I tried finding the site again but no luck.
I've never had time to try and understand it properly.

[kamemasta]

TygerDawg is pretty correct about language and rotations. Converting Euler to Cartesian is above me, so I use TRAFO... unfortunately, the link above to the Trafo program is not the same TRAFO I was refering to. It used to be easy to find!! Hang tight.

[scotch99]

Converting Euler to Cartesian is above me, so I use TRAFO... unfortunately, the link above to the Trafo program is not the same TRAFO I was refering to. It used to be easy to find!! Hang tight.

kamemasta, why you just can't post this program on forum? 
I really can't find anything else than Trafo from http://anorganik.uni-tuebingen.de/klaus/soft/index.php?p=trafo/trafo