Simrad ROBERTSON AP45 manual Rudder, Weather

Page 2-4	Robertson AP45 Autopilot
	Operation

These buttons are used to alter various settings. Each time one button is pressed, the value shown on the Information Display, will increase (+) or decrease (—) by one unit. The value is also shown as a graphical bar. If a button is pressed for more than two seconds, the value will automatically increase or decrease until the button is released.

RUDDER

When the RUDDER button is pressed, the Information Display shows selected RUDDER value. The RUDDER value sets the ratio between rudder angle and heading error (p-factor).

Example: If RUDDER is set to 1.0 and there is a heading error of 2 degrees, the rudder angle will be 2 degrees. (Heading error x RUDDER value = rudder angle).

The correct RUDDER setting is dependant upon the size and speed of the vessel. The RUDDER value should increase with decreasing speed.

RUDDER should be set separately in WORK-mode, to optimise the autopilot performance.

Examples of incorrect RUDDER settings:

A value which is too low gives relatively large and slow oscillations (s-ing) around set course, and several rudder commands are given in the same direction before the vessel is back on course.

A value which is too high will give quick and in worst case increasing oscillations (s-ing) around set course.

A

B

The correct setting of RUDDER will be approximately in the middle of the settings described in A and B above.

WEATHER

The WEATHER setting determines the amount of degrees the vessel may fall off the set course before any response is given from the rudder. In calm weather it should be set to OFF which means that theoretically the autopilot allows no deviation from set course. The WEATHER value should be increased with increasing sea state.

In conditions where active steering is required, (e.g. following sea condition), the value should be reduced.

Course selection The course selection section on the autopilot consists of a course display, a course selector knob and two course adjustment buttons, PORT and STBD.

The Course Display gives a readout of actual ships heading in MANUAL-mode and set course in AUTO-, WORK- and NAV-mode. The selected mode is also shown to the left on the display by the same letter as on the mode buttons.

The course selector knob is used for major course changes in AUTO- and WORK- mode. To activate the knob it must be pressed down, released, and then turned. Clockwise turns gives a starboard course change and vice versa. One revolution on the course selector knob is equal to a 60 degree course change. If the knob is not turned within 10 seconds, it has to be pressed again.

Simrad Robertson AS

Egersund - Norway