Method, apparatus, and medium for calibrating compass sensor in consideration of magnetic environment and method, apparatus, and medium for measuring azimuth using the compass sensor calibration method, apparatus, and medium

A method of measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• (a) acquiring magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• (b) fitting the acquired magnetic force data to an ellipse function;
• (c) transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• (d) calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• (e) calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor is within a predefined threshold range.

A method of measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• (a) acquiring magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• (b) fitting the acquired magnetic force data to an ellipse function;
• (c) transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• (d) calculating quality of calibration by comparing the acquired magnetic force data and the ellipse function;
• and
• (e) calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the quality of calibration is within a predefined threshold range.

A method of measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• (a) acquiring magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• (b) fitting the acquired magnetic force data to an ellipse function;
• (c) transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• (d) calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, and calculating quality of calibration by comparing the acquired magnetic force data and the ellipse function, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• (e) calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor and the quality of calibration are both within respective corresponding predefined threshold ranges.

An apparatus for calibrating a compass sensor in consideration of a magnetic environment, the apparatus comprising:

• a data acquiring module which acquires magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• an ellipse fitting module which fits the acquired magnetic force data to an ellipse function;
• a compass calibration module which transforms the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• and
• a distortion factor calculation module which calculates a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating the degree to which a magnetic field is distorted.

An apparatus for measuring the azimuth of a compass sensor in consideration of a magnetic environment, the apparatus comprising:

• a data acquiring module which acquires magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• an ellipse fitting module which fits the acquired magnetic force data to an ellipse function;
• a compass calibration module which transforms the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• a distortion factor calculation module which calculates a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• an azimuth calculation module which calculates the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor is within a predefined threshold range.

An apparatus for measuring the azimuth of a compass sensor in consideration of a magnetic environment, the apparatus comprising:

• a data acquiring module which acquires magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• an ellipse fitting module which fits the acquired magnetic force data to an ellipse function;
• a compass calibration module which transforms the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• a calibration quality calculation module which calculates quality of calibration by comparing the acquired magnetic force data and the ellipse function;
• and
• an azimuth calculation module which calculates the azimuth of the compass sensor based on calibrated data of the compass sensor if the quality of calibration is within a predefined threshold range.

An apparatus for measuring the azimuth of a compass sensor in consideration of a magnetic environment, the apparatus comprising:

• a data acquiring module which acquires magnetic force data by rotating a compass sensor 360 degrees, the compass sensor comprising a biaxial magnetometer;
• an ellipse fitting module which fits the acquired magnetic force data to an ellipse function;
• a compass calibration module which transforms the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• a distortion factor/calibration quality calculation module which calculates a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, and calculates quality of calibration by comparing the acquired magnetic force data and the ellipse function, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• an azimuth calculation module which calculates the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor and the quality of calibration are both within respective corresponding predefined threshold ranges.

At least one computer readable medium storing computer readable instructions that control at least one processor to implement a method for calibrating a compass sensor in consideration of a magnetic environment, the method comprising:

• fitting acquired magnetic force data acquired by the compass sensor to an ellipse function;
• transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• and
• calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating a degree to which a magnetic field is distorted.

At least one computer readable medium storing computer readable instructions that control at least one processor to implement a method for measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• fitting acquired magnetic force data acquired by the compass sensor to an ellipse function;
• transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor is within a predefined threshold range.

At least one computer readable medium storing computer readable instructions that control at least one processor to implement a method of measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• fitting acquired magnetic force data acquired by the compass sensor to an ellipse function;
• transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• calculating quality of calibration by comparing the acquired magnetic force data and the ellipse function;
• and
• calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the quality of calibration is within a predefined threshold range.

At least one computer readable medium storing computer readable instructions that control at least one processor to implement a method of measuring the azimuth of a compass sensor in consideration of a magnetic environment, the method comprising:

• fitting acquired magnetic force data acquired by the compass sensor to an ellipse function;
• transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin;
• calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, and calculating quality of calibration by comparing the acquired magnetic force data and the ellipse function, the distortion factor indicating the degree to which a magnetic field is distorted;
• and
• calculating the azimuth of the compass sensor based on calibrated data of the compass sensor if the distortion factor and the quality of calibration are both within respective corresponding predefined threshold ranges.