AUTOPILOT
To find the optimal [RUD] and [CRD] settings at different boat speeds, or when the boat
is towing, follow the procedures outlined in #3 and #4 above. Make a record of the
different settings needed to control the boat at all typical speeds, loads and weather
conditions normally experienced. Due to the wide dynamic control range and self tuning
features of the microprocessor control, settings determined for cruising speed in calm
seas may be found acceptable without further change at slower speeds and in heavier
seas.
5. The compass damping [SEA] setting is a combination of yaw dead-band (compass
sensitivity) and compass damping. The minimum setting may only be used under calm
sea conditions to avoid unnecessary rudder correction due to compass acceleration
errors.
Smaller boats and high speed boats which are subject to more acceleration in lighter
seas will have to use higher settings.
Larger and more stable boats can use lower settings since there is less compass
disturbance. Factory default setting should work on most boats in light to moderate sea
conditions.
Following seas, no matter how rough, may require lower settings to catch course error
trends quickly in order to minimise excessive yaw and steering activity.
6. Automatic Trim Calibration [ATC] adjustment is not critical. It constantly compares
the course set against the course steered. The automatic trim slowly applies more
rudder as necessary to reduce any persistant errors to zero. Such errors may exist due
to wind, waves or other unbalanced forces such as single screw operation of a twin
screw boat, an off centre tow or weather helm on a sailing boat. If the trim time is set
too high, it will take a long time to eliminate the course error. If it is set too low it can
start to degrade course stability.
In general, longer trim times (higher settings) should be set for large boats and sailing
boats and shorter trim times (lower settings) for small boats and high speed planning
boats. The factory default setting should be acceptable for all but extreme applications.
If after fine tuning all routines and auto-deviation routine has been done and poor
steering is noted only on some but not all headings, magnetic interference is present
which must either be compensated for by a compass adjuster and/or another compass
location must be found.
60