Autopilot system for a vessel

An autopilot system for a vessel, said vessel having a location relative to the Earth, said location having a corresponding dip angle of the Earth's magnetic field, said autopilot system comprising:

• memory means for storing at least one pre-set heading direction;
• heading means for determining an apparent orientation of said vessel relative to a reference direction;
• means for determining the magnetic dip angle corresponding to the location of said vessel and for generating a dip signal dependent on said magnetic dip angle;
• steering correction means for:
• (i) generating a correction value dependent on the difference between said apparent orientation and said pre-set heading direction,
• (ii) generating a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said dip signal;
• and
• steering means for controlling the actual orientation of said vessel, said steering means including movable direction vessel-setting means for setting the actual orientation of said vessel in dependence on the current position of said movable direction vessel-setting means, and means for varying the position of said movable direction vessel-setting means in dependence on said correction value.

An autopilot system for a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• memory means for storing at least one pre-set heading direction;
• heading means for determining an apparent orientation of said vessel relative to a reference direction;
• means for determining the vertical component of the Earth's magnetic field corresponding to the location of said vessel and for generating a field signal dependent on said vertical component;
• steering correction means for:
• (i) generating a correction value dependent on the difference between said apparent orientation and said pre-set heading direction, and
• (ii) generating a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said field signal;
• and
• steering means for controlling the actual orientation of said vessel, said steering means including movable vessel-direction setting means for setting the actual orientation of said vessel in dependence on the current position of said movable direction vessel-setting means, and means for varying the position of said movable direction vessel-setting means in dependence on said correction value.

An autopilot system for a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• memory means for storing at least one pre-set heading direction;
• heading means for determining an apparent orientation of said vessel relative to a reference direction;
• means for determining the horizontal component of the Earth's magnetic field corresponding to the location of said vessel and for generating a field signal dependent on said horizontal component;
• steering correction means for:
• (i) generating a correction value dependent on the difference between said apparent orientation and said pre-set heading direction, and
• (ii) generating a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said field signal;
• and
• steering means for controlling the actual orientation of said vessel, said steering means including movable vessel-direction setting means for setting the actual orientation of said vessel in dependence on the current position of said movable direction vessel-setting means, and means for varying the position of said movable direction vessel-setting means in dependence on said correction value.

An autopilot system for a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• memory means for storing at least one pre-set heading direction;
• heading means for determining an apparent orientation of said vessel relative to a reference direction;
• means for determining the latitude corresponding to the location of said vessel and for generating a latitude signal dependent on said latitude;
• steering correction means for:
• (i) generating a correction value dependent on the difference between said apparent orientation and said pre-set heading direction, and
• (ii) generating a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said latitude signal;
• and
• steering means for controlling the actual orientation of said vessel, said steering means including movable vessel-direction setting means for setting the actual orientation of said vessel in dependence on the current position of said movable direction vessel-setting means, and means for varying the position of said movable direction vessel-setting means in dependence on said correction value.

A method of controlling the orientation of a vessel, comprising:

• storing at least one pre-set heading direction;
• determining the apparent orientation of said vessel relative to a reference direction;
• generating a correction value dependent on the difference between said apparent orientation and said pre-set heading direction, and generating a modification value dependent on the difference between said apparent orientation and said reference direction, said modification value being independent of said correction value;
• generating a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said modification value;
• controlling the orientation of said vessel by varying the actual orientation of said vessel in dependence on said correction signal.

A method of controlling the orientation of a vessel, comprising:

• storing at least one pre-set heading direction;
• determining an apparent orientation of said vessel relative to a reference direction;
• determining the magnetic dip angle corresponding to the location of said vessel;
• generating a dip signal dependent on said magnetic dip angle;
• generating:
• (i) a correction value dependent on the difference between said apparent orientation and said pre-set heading direction,
• (ii) a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said dip signal;
• and
• controlling the orientation of said vessel by varying the actual orientation of said vessel in dependence on said correction signal.

A method of controlling the orientation of a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• storing at least one pre-set heading direction;
• determining an apparent orientation of said vessel relative to a reference direction;
• determining the vertical component of the Earth's magnetic field corresponding to the location of said vessel;
• generating a field signal dependent on said vertical component;
• generating:
• (i) a correction value dependent on the difference between said apparent orientation and said pre-set heading direction,
• (ii) a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said field signal;
• and
• controlling the orientation of said vessel by varying the actual orientation of said vessel in dependence on said correction signal.

A method of controlling the orientation of a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• storing at least one pre-set heading direction;
• determining an apparent orientation of said vessel relative to a reference direction;
• determining the horizontal component of the Earth's magnetic field corresponding to the location of said vessel;
• generating a field signal dependent on said horizontal component;
• generating:
• (i) a correction value dependent on the difference between said apparent orientation and said pre-set heading direction,
• (ii) a correction signal, said correction signal being the product of said correction value and a gain value, which gain value is variable in dependence on said field signal;
• and
• controlling the orientation of said vessel by varying the actual orientation of said vessel in dependence on said correction signal.

A method of controlling the orientation of a vessel, said vessel having a location relative to the Earth, said autopilot system comprising:

• storing at least one pre-set heading direction;
• determining an apparent orientation of said vessel relative to a reference direction;
• determining the latitude corresponding to the location of said vessel;
• generating a latitude signal dependent on said latitude;
• generating:
• (i) a correction value dependent on the difference between said apparent orientation and said pre-set heading direction,
• (ii) a correction signal, said correction signal being the product of said correction value and gain value, which gain value is variable in dependence on said latitude signal;
• and
• controlling the orientation of said vessel by varying the actual orientation of said vessel in dependence on said correction signal.