Navitron NT888G MK2, Руководство по эксплуатации

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NT888G MK2 AUTOPILOT OPERATING MANUAL
2.31 Setting the Rudder Limit Control.
The Rudder Limit Control defines the maximum angle of rudder that the Autopilot is
able to apply with the exception of Counter Rudder, which overrides the Rudder Limit
setting.
NB. This results in a safe operating mode wherein rudder angle is limited for any
angle of course change ordered to a new heading and for any angle of rudder
ordered by the Autotrim process (APH). However, high rates of departure from
the course steered will continue to attract large angles of ‘check’ rudder that
might be necessary to quickly arrest the vessel in a potential broach condition
etc.
The Rudder Limit control can be set from 5° to 50° in 5° steps or switched OFF via
the LIMITS Menu.
When the limit of prescribed angle is reached, single bleep and a flashing RUDDER
LIMIT message appears in the rudder position display box.
As a general rule, the Rudder Limit control should be set to limit the angle of
rudder applied such that any angle of course change ordered can be safely
executed within the turning capability of the vessel and it’s operational
considerations (warp tensions if towing etc.)
NB. If Track Steering mode is operational using the HTC sentence, it is
possible for the Track Control system to override the Rudder limit value
set within the Autopilot LIMITS Menu.
2.32 Setting Rate of Turn Control.
(i) Actual RATE OF TURN (ROT) is internally calculated by the Autopilot
system if it is not available from the selected heading source via the
$xxROT sentence.
Note that the internally set Rate of Turn target value can be overridden by
a Type Approved Track Control system via the complex $xxHTC sentence.
NB. The operational ROT (deg/sec or deg/min) is programmed within the
Autopilot via the LIMITS Menu (section 1.9) and can be overruled by Track
command but absolute MAXIMUM Safe Rate of Turn can also be set via
the
SET UP Menu and is unaffected by Track data. (See Section 2.33).
The ROT CALIBRATION Value:-
The ROT calibration value relates to the length and speed of the vessel and is
entered in the Set Up Menu during initial installation.
It is essential that the ROT calibration value accurately reflects the vessels
characteristics in order that the specified ROT can be achieved as quickly and
efficiently as possible whilst minimising overshoot and rudder movement.
The value of ROT calibration can be adjusted manually or can be calculated
automatically during sea trials. To optimise the value of ROT calibration automatically
at normal steaming speed proceed as follow:-