Alphatron ALPHASEAPILOT MFC - The Counter Rudder Control Setting

Operating manual ALPHASEAPILOT MFC Issue 1.1 Page 53 of 84
ALPHASEAPILOT MFC
2.24 The Counter Rudder Control Setting
Evaluating the Counter Rudder Setting:
The Autopilot Counter rudder function continuously monitors the rate of change of heading
(Rate of Turn) of the vessel and is principally responsible for the application of ‘Counter’ or
‘Opposite’ rudder as follows: -
Counter - Counters or ‘checks’ any sudden departure from the steady
course steered by applying exaggerated short-term angles of rudder measured against the rate
of turn away from the specified heading.
Evaluating the Counter Rudder Setting:
Opposite - Monitors the closing rate towards a new course to prevent
‘overshoot’ by removing rudder early and applying opposite rudder to
‘meet’ and stabilise the vessel on the new heading specified.
Adjusting the Counter Rudder Setting:
The Counter Rudder effect may be increased or decreased by adjustment of the Autopilot
COUNTER value via the CONTROLS Menu between the Limits of 1 to 9 where 9 produces
maximum counter rudder.
(i) With the Autopilot engaged (ON) and the vessel underway on a stable heading,
use the Autopilot Set Course knob to order a course change of 30° Port or Stbd of
the current heading.
(ii) Observe the response of the vessel noting whether overshoot occurs or whether
the vessel is prematurely arrested in it’s turn to the new heading.
(iii) Repeat the 30° course change in the opposite direction to gain an average
evaluation.
Vessel Consistently Overshoots - Increase the Counter Rudder Value
Vessel Prematurely Arrested - Decrease the Counter Rudder Value
The optimum Counter setting has been achieved when the vessel turns efficiently to the new
heading and stabilises without overshoot.
To increase / decrease the Counter Rudder value: -
(iv) Use the CONTROLS key 4 times to select “COUNTR” in the Menu.
(v) Rotate the illum. control (+/-) to increase or decrease the flashing “COUNTR”
No. (1 to 9) as required.
(The flashing counter value will timeout after a period of 30 seconds and the
display will automatically revert to the standard operational mode).