Overlap Areas Of Axis Angles; Examples Of Ambiguities Of Position - Siemens SINUMERIK 840D sl Function Manual

Kinematic Transformation (M1)
7.6 Cartesian PTP travel
7.6.2

Overlap areas of axis angles

TU address
In order to approach axis angles in excess of ±180° without ambiguity, the information must
be programmed in the TU (turn) address. The TU address thus represents the sign of the
axis angles. This allows an axis angle of |θ| < 360° to be traversed without ambiguity.
Variable TU contains a bit, which indicates the traversing direction for every axis involved in
the transformation.
● TU bit=0: 0° ≤ θ < 360°
● TU bit=1: 360° < θ < 0°
The TU bit is set to 0 for linear axes.
In the case of axes with a traversing range >±360°, the axis always moves across the
shortest path, because the axis position cannot be specified uniquely by the TU information.
If no TU is programmed for a position, the axis always traverses via the shortest possible
route.
7.6.3

Examples of ambiguities of position

The kinematics for a 6axis joint have been used to illustrate the ambiguities caused by
different joint positions.
Figure 7-24
548
Ambiguity in overhead area
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Extended Functions