Computer Modeling for Mechanical Excavators
Computer Model for Roadheaders
prediction for road header machines is more difficult compared to full-face
machines (e.g. TBM). This is partly because operator's skill affects the
production rate significantly. Roadheaders also are less rigid because the
cutterhead is mounted on a boom that must transfer energy from the machine.
consists of several modes of cutting: sumping (into the face), arcing (across
the face) and shearing (down the face). In each mode, only part of the
cutterhead contacts the rock. Even among cutters in contact with the face, the
depth of penetration varies, depending on the spatial and temporal position of
each cutter. The production rate can vary between two operators depending on
their choices of cutterhead movements, sequencing and use of available power.
variability of roadheader machine operation means that exact performance
predictions cannot be expected from semi-theoretical methods that use cutting
forces. However, the maximum production rate achievable in each cutting mode
does indicate the limits of the machine and provides an upper bound on the
expected production rates.
The effects of rock joints, fractures, inflows, etc. on the performance of these machines also are not modeled easily. Empirical models developed for performance prediction of partial face machines generally have had more success than semi-theoretical models.
Some of them are: