Siemens SINUMERIK 840D sl Function Manual page 97

Type 2 polynomials
Orientation polynomials of type 2 are polynomials for coordinates
PO[XH]:
PO[YH]:
PO[ZH]:
Polynomials for angle of rotation and rotation vectors
For 6-axis transformations, the rotation of the tool around itself can be programmed for tool
orientation. This rotation of a third rotary axis is described either by an angle of rotation or by
a rotation vector, which is perpendicular to the tool direction in the plane.
In addition, a polynomial for rotation with PO[THT} of the orientation vector can be
programmed in these three cases. This is always possible if the kinematic transformation
applied, supports rotary angles.
Angle of rotation with ORIPATH and ORIPATHS
For path relativeorientation interpolation relative to the path ORIPATH or ORIPATHS , the
additional rotation can be programmed with the angle THETA=<...>. Polynomials up to the
5th degree can also be programmed with PO[THT]=(...) for this angle of rotation.
The three possible angles, i.e. lead angle, tilt angle and angle of rotation, have the following
meaning with respect to the rotation effect:
LEAD
TILT
THETA
How the angles LEAD and TILT are to be interpreted, can be set with the following machine
data:
MD21094 $MC_ORIPATH_MODE (setting for path relative orientation ORIPATH)
In addition to the constant angles programmed with LEAD and TILT, polynomials can be
programmed for lead angle and tilt angle. Polynomials are programmed with the PHI and PSI
angles:
PO[PHI] = (a2, a3, a4, a5)
PO[PSI] = (b2, b3, b4, b5)
Polynomials can be programmed up to the 5th degree for both angles. The angle values at
the block end are programmed with the NC addresses LEAD= <...> bzw. TILT = <...>.
The higher polynomial coefficients, which are zero, can be omitted when programming. For
eexample PO[PHI] = (a2) programs a parabola for the lead angle LEAD.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
x coordinate of the reference point on the tool
y coordinate of the reference point on the tool
z coordinate of the reference point on the tool
Angle relative to the surface normal vector in the plane put up by the path
tangent and the surface normal vector
Rotation of orientation in the z direction or rotation about the path tangent
Rotation around the tool direction. Is only possible if tool orientation has a
total of 3 degrees of freedom, see "Extension of the generic transformation
to 6 axes".
Polynomial for the LEAD angle
Polynomial for the TILTangle
F2: Multi-axis transformations
1.9 Orientation
97