New measurement and control technology in tunnelling - Tunnel Engineering: Basics and Additional Services for Design and Construction - page 258

Movement parameters. The machine essentially has six degrees of freedom; three de-
scribing its spatial movements, in other words its position, and three individual degrees of
freedom in its alignment. The parameters to be determined are (Fig. 6-14):
- Height divergence above axis.
- Side divergence from axis.
- Travelled distance.
- Pitch angle.
- Yaw angle.
- Roll angle.
These parameters have to be determined in relation to a locally defined coordinate system.
The movements of the cutting boom each have one degree of freedom: lifting - lowering,
slewing and the length (extension) of the cutting boom. These are first measured as ma-
chine-related coordinates and converted into the locally defined tunnel coordinate system
using the data describing the machine position (Fig. 6-14). The movement parameters of
machines with in-line and cross-cutting head mounting do not differ. In practice, the de-
termination of the excavated distance is not integrated into the machine control system but
undertaken by the personnel. When a curve is driven, this is undertaken at a close spacing
with the laser instruments installed in the tunnel being moved forward.
Figure 6-14 Degrees of freedom of
movement of a roadheader with in-line
cutting head.