Agriculture Reference
In-Depth Information
guidance along straight lines
without prior circuitous path
guidance along straight lines
with one prior circuitous path
guidance by fixed line GPS
with alternating blank paths
guidance along curved lines
with one adapted path
guidance along concentric circles
in center-pivot irrigated field
guidance along prior path lines
in irregular shaped field
Fig. 4.6
Driving patterns (Courtesy of Agri Con GmbH, supplemented and altered)
However, the trend is from retrofi tting of used machines to
factory-fi tting
of
new vehicles with the components that are needed. For this, the actuator for auto-
matic guidance replaces the conventional hydraulic steering motor and thus does
not operate in the drivers cab any more. Yet this makes it more diffi cult to use the
same actuator on several vehicles. On the other hand, factory fi tting saves much
time by doing away with harnessing and bothering about technical details.
Effi ciency and precision of fi eld operations depend on the
driving pattern
that is
used (Fig.
4.6
). In rectangular fi elds, circuitous driving around and around parallel to
all fi eld boundaries should be avoided whenever possible. If this driving pattern is
used without disengaging the implements, crescent-shaped gaps that are not dealt
with are inevitable at the corners (see text near Fig.
4.2
). On the other hand, when
driving around is done in a dead end pattern with a turn at each corner, time is lost
because of the high number of turns per unit area. The lowest number of turns in
rectangular fi elds with dead end driving patterns is needed when driving is done
parallel to the longest fi eld side (Fig.
4.6
, top). With many machines, this can be in
the pattern of adjacent strips. However, sometimes this would require a back-up for
every headland turn. This can be avoided by using fi xed line GPS guidance and alter-
nating between strips that are dealt with and left blank at fi rst (Fig.
4.6
, top right).
There can be obstacles in rectangular fi elds for driving up and down parallel to the
longest fi eld side. With some harvesting machines, it must be taken into account that
unloading onto wagons on-the-go is possible only to one side. Consequently, with
these machines driving up and down along adjacent strips is not possible. Yet this
