Husqvarna Automower 305, Technical Manual, Page: 14 / 94

English - 12
1.11 Guide wire
The guide wire, together with the part of the boundary
wire that comprises the return to the charging station,
is called the guide wire. The current in the guide wire
always goes from the guide wire to the left in the
connection between guide wire and boundary wire.
The strength of the guide signal varies like the A signal
depending on the distance to the guide wire. Inside
the guide wire the signal is positive and the strength
subsequently diminishes the farther away from the wire
you get. Outside the guide wire, the signal is negative
and the strength of the signal diminishes more rapidly.
The area inside the guide wire is designated the guide
area. The robotic lawnmower always tracks the left
side of the guide wire in the direction towards the
charging station, i.e. the mower follows the negative
values of the guide signal.
The strength of the signal in the guide loop depends
on the loop’s length. The guide loop must therefore
not be longer than approx. 250 metres.
The longer the guide loop, the lower the strength of
the signal and the more difficult it is for the robotic
lawnmower to follow the guide wire. If the strength of
the signal becomes too low, the robotic lawnmower,
for example may stop following the guide wire when
it reaches an outlying corner.
The strength of the guide signal also varies along
the guide loop depending on the proximity to other
parts of the guide loop and is affected by islands,
headlands, passages and corners.
To reduce the risk of the mower losing contact with
the wire in corners, it is recommended that the wire
is not laid in 90 degree angles. It is better to lay the
wire in two 135 degree angles.
1.12 Guide width
Guide width is a measure of how far from the guide
wire the mower is allowed to travel when it is following
it to and from the charging station. The area beside the
wire which the mower then uses is called the corridor.
The guide width for GARDENA R40Li cannot be
changed but there are three possible guide width
settings for the other models:
Table 3: Guide width
Guide width
The mower’s distance
from the guide wire
Narrow 0 cm
Medium
0 + 30-50 cm
Wide 0 + 30-100 cm
With the guide width Wide, the robotic lawnmower
mows at various distances to the guide wire at
different charging cycles. A garden that is open and
free of narrow passages should have a wide corridor.
With
Medium width, the robotic lawnmower mows
at various distances to the guide wire at different
charging cycles, but not as far away from the guide
wire as is the case when Wide is selected. The
medium corridor setting should be selected for a
garden with obstacles close to the guide wire and/or
passages that do not allow for a wide corridor. The
GARDENA R40Li always uses this guide width and it
cannot be changed.
With
Narrow guide width, the robotic lawnmower runs
straight over the guide wire. Narrow is not normally
recommended, but in a garden with one or a number
of narrow passages, a narrow corridor may be the
only option. The narrow corridor setting increases the
risk of tracks forming along the guide wire. With this
setting the mower can negotiate passages down to
100 cm wide if the passage is bounded by trenches,
or 120 cm wide if the passage is bounded by walls.
1. FUNCTION
3012-949
3012-993
135º
135º
90º
3012-953