Siemens sinumerik 840D sl Function Manual page 95

Interpolation of the angle of rotation
Higher degree coefficients can be omitted from the coefficient list (..., ....) if these are all
equal to zero.
In such cases, the end value of the angleand the constant and linear coefficient
polynomial cannot be programmed directly.
The linear coefficient
The end angle
The start angle
value of the previous block. The constant coefficient of the polynomial is defined by the
starting angle of the polynomial.
The rotation vector is always perpendicular to the current tool orientation and forms the
angle THETAin conjunction with the basic rotation vector.
Note
During machine configuration, the direction in which the rotation vector points at a specific
angle of rotation can be defined, when the tool is in the basic orientation.
Formula
In general, the angle of rotation is interpolated with a 5th degree polynomial:
θu=θ
For the parameter interval 0 ... 1, this produces the following values for linear coefficients:
d =θ
1
Interpolation of the rotation vector
The programmed rotation vector can be interpolated in the following way, using modal G-
codes:
• ORIROTA (orientation rotation absolute):
• ORIROTR (orientation rotation relative):
• ORIROTT (orientation rotation tangential):
Special functions: 3-Axis to 5-Axis Transformation (F2)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
d
is defined by means of the end angle
n
q
is derived from programming of the rotation vector.
e
q
is derived from the start value of the rotation vector, resulting from the end
s
+d u+d u +d u +d
2 3
s 1 2 3 4
−θ −d −d −d −d
e s 2 3 4 5
The angle of rotation THETA is interpreted with reference to an absolute direction in
space. The basic direction of rotation is defined by machine data.
The angle of rotation THETA is interpreted relative to the plane defined by the start and
end orientation.
The angle of rotation THETA is interpreted relative to the change in orientation. That
means the rotation vector interpolation is tangential to the change in orientation for
THETA=0.
u +d u
4 5
5
Detailed description
2.10 Orientation vectors
d
of the
n
q
in degrees.
e
(14)
(15)
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