Guide Wire; Searching Methods To Find The Charging Station - Husqvarna Automower 420 Technical Manual

1.9 Guide wire

The guide wire, together with the part of the bounda-
ry wire that comprises the return to the charging sta-
tion, is called the guide wire. The current in the guide
loop 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 loop.
Inside the guide loop the signal is positive and the
strength subsequently diminishes the farther away
from the wire you get. Outside the guide loop, the
signal is negative and the strength of the signal di-
minishes more rapidly. The area inside the guide loop
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 on 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. 400 meters.
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.
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, head-
lands, passages and corners.
To reduce the risk of the mower losing contact with
the wire in corners, it is recommended to not lay the
wire at 90 degree angles. It is better to lay the wire in
two 135 degree angles.
1.10 Searching methods to find the
charging station
When the charge level in the battery has dropped to
1,000 mAh or the voltage in the battery has dropped
to 17.5 volts, the robotic lawnmower shuts down the
blade motor and starts searching for the charging
station.
Automower® can be set to search for the charging
station in one or more of 3 different ways: Irregular,
Follow boundary home and Follow guide home.
Using the settings options in the Installation - Find
charging station menu, the three search methods
can be combined to optimize the search for the
charging station. The required search method or
methods depends on the shape of the garden.
Irregular is the basic search method for finding the
charging station and works well in open areas. There
is no risk of tracks forming. The Follow boundary
home and Follow guide home search methods can
however give considerably shorter search times in
more complex installations with areas divided by
passages or openings.
English - 14
1. FUNCTION
135º 135°
135° 135º
90°
90º