Variable or Precision Point?

[tdevine77]

Ok, what is the difference between a Variable position and a Precision point?

I think that a variable positional data is referenced off the tool tip? and positional data is saved as XYZ and OAT, XYZ meaning the cartesian cordinate system position and OAT in rotation angle of the tip. I think that a variable position does not care where each individual joint is located as long as the tool tip is in the correct location. Is this correct?


I think a Precision point only looks at the position of each joint and not the tool tip? This is where I get confused at. So the position of each joint has to be at the taught position unlike a variable position where it just looks at the position of the tip. Is this correct? Also how is the data saved in a precision point so the robot knows were each joint needs to be. Instead of XYZ OAT for variable data how is the precision point data saved? Is it just in angles for each of the 6 joints?

I get confused with this and am not sure I know what I am talking about would apreciate it if someone could straighten me out on this!

Thanks
Tommy D

[TygerDawg]

Going out on a limb here and making an ASS-U-MEption.  The Kawa language was a derivative of the old VAL language, Adept's V+ is a derivative of VAL, and I know V+.  So.....

I don't recognize the term "variable position" but your description looks correct:  Euler-math Cartesian location of the Tool Center Point. 

{X, Y, Z, (and three more values defining coordinate system axis rototions as defined by Kawa)}

Precisioin Point in the V+ language is indeed "joint-angle location".  It's mis-named because there's no extra "precision" involved.

{J1, J2, J3, J4, J5, J6}

[tdevine77]

Thanks for the reply, I am now more confident in my programming and teaching ability to other maintenance technicians

Tommy D

[roboperson]

There are 3 basic location variables. Transformation, Precision, and Compound Transformation Expression.
Transformation Variable - X,Y,Z of the tool top position in base coordinates. O,A,T is the tool direction.
Precision Variable - Joint angles
Compound Transformation Expression - Using multiple variables setting the value at the right most variable in the expression.
Depending on what your doing with the varible would determine which you would use, for example if your wanting to just teach a set point, if your wanting to do a transformation or decompose, offset of locations, etc.
If you are using block step programming then precision points are always used when you press record. This can be seen if you look at a back up and see the location beings with #.