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Robertson AP9 Adaptive Autopilot
2.5
Sea trial procedure
Note !
2-22
This section describes the procedures to follow when the
autopilot is in use for the first time or after a master reset. The
activity is here called the sea trial. The purpose is to let the
autopilot learn the ships manoeuvring characteristics. During
seatrial the autopilot is extra sensitive to the ships heading
changes and rudder movement and it is therefore important
that the procedure below is followed carefully. The (automatic
steering) procedure will normally take 30 to 60 minutes to
perform.
2.5.1 Automatic steering
Do not use the autopilot before reaching open waters. The
waters should allow speeds close to the vessel's service speed,
and a lot of manoeuvring. The autopilot might not perform
well right after a master reset.
1. When in open waters, enter the automatic steering mode as
described in the Quick reference. Immediately; start making
a series of port and starboard course changes. Start with a
magnitude of 5 degrees to both port and starboard. Increase
the course changes in steps of 5 to 40 degrees.
During this manouvring the speed of the vessel should
at least be 80% of the service speed.
While manoeuvring you should regularly check on Seatrial
setup the SEA TRIAL parameter. This is a quality indicator,
starting at 9999 after a master reset, and decreasing to 0000,
which indicate that the sea trial is finished. Each digit plays
a specific role, indicating (from left to right) the further need
for port turns, port rudder usage, starboard rudder usage and
starboard turns.
It is likely that the turn indicators will reach 0 before the
rudder indicators. To make these indicators decrease faster it
is necessary to make the autopilot use more rudder. This can
be done by starting a turn and then, before the turn is
finished make a new turn in the opposite direction.
However, when the SEA TRIAL indicator have reached
0330 or lower and the steering is acceptable you may
consider this part of the sea trial done and let the indicator
continue to decrease during normal manoeuvring.
2. Tune the following seatrial setup parameters of the course-
keeping controller: RUDD GAIN, MIN RUDD and DEADBAND.
Their functions are explained in section Seatrial setup,
section 2.3.4. Useful hints can be found in section Control
20169140B
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