NT888G MK2 AUTOPILOT OPERATING MANUAL
2.4 The CONTROLS Menu / Counter Rudder (Continued).
c)
Use the rotary (+/-) illum. control to set value “
1-9
” as required.
2.4 (v) Autothrust.
The Autothrust Mode refers to Autopilot control of the Thruster(s) which may be
confined to Thruster ONLY or combined with Rudder to provide Rudder AND
Thruster response to Autopilot steering demands.
The amount of Thruster power required – whether alone or combined with Rudder
– will vary over a very wide range dependent upon vessel speed, laden condition
and external forces (towing/windage/Set etc.).
From the viewpoint of Adaptive Autopilot control and performance, automatic
adjustment of the Thrust value (amount) is time consuming and inefficient
compared with the straightforward and immediate result gained by manual
adjustment.
For this reason, the Autothrust parameter may easily be changed manually via
access to the
CONTROLS
Menu.
(Related operational conditions would involve vessels underway at low speeds
due to towing, winching or navigational considerations, where all conditions
combined to degrade Autopilot course keeping when using Rudder(s) only. In this
case, the Rudder Mode of control would be retained but would be assisted by the
introduction of Bowthruster action via selection of the Autopilot
THRUSTER
Mode. Manual value adjustment of the Thruster contribution would
then be made to rapidly optimise steering performance).
To adjust AUTOTHRUST gain:-
a)
Use the “
CONTROLS
” key to enter the Controls Menu.
b)
Use the “
CONTROLS
” key again to select “
AUTOTHRUST
” box
followed by flashing value “
1-9
” (where 9 = max. thrust).
c)
Use the rotary (+/-) illum. control to set value “
1-9
” as required.
2.4 (vi) Turn Type (ROT or RAD).
Rate of Turn (ROT) and Radius of Turn (RAD) control is provided by the Autopilot
system and can be active - if selected via the
CONTROLS
Menu - in both the
Adaptive and Non Adaptive Autopilot operating modes.
If no ROT or RAD control is required, the facility can be set to “OFF”.
Radius of Turn Operating Note:-
It should be noted that Speed input data is essential to Radius of Turn control in
the form of Speed over the Ground (SOG). If SOG data is absent, or, if vessel
SOG is too low to maintain the constant radius turn demanded versus prevailing
conditions, Autopilot alarms will result.
NO SOG DATA = NO RADIUS OF TURN CONTROL FACILITY.
