Method of compensating tilt using two-axis geomagnetic sensor, and acceleration sensor, and apparatus thereof

A method of compensating tilt comprising:

• measuring geomagnetic field values of the X and Y axes tilted at a predetermined angle by using a two-axis geomagnetic sensor;
• measuring gravity acceleration values of the X, Y, and Z axes in the tilted state by using a three-axis acceleration sensor;
• judging that the Y axis of the two-axis geomagnetic sensor is perpendicular when the Z-axis and X-axis gravity acceleration values are substantially all 0, and storing the geomagnetic field value measured in the Y axis of the two-axis geomagnetic sensor as a Z-axis geomagnetic field value;
• judging that the X axis of the two-axis geomagnetic sensor is perpendicular when the Z-axis and Y-axis gravity acceleration values are substantially all 0, and storing the geomagnetic field value measured in the X axis of the two-axis geomagnetic sensor as a Z-axis geomagnetic field value;
• and
• calculating an azimuth angle by using the geomagnetic field values of three axes so as to compensate the azimuth angle changed by tilt.

A method of compensating tilt comprising:

• measuring geomagnetic field values of the X and Y axes tilted at a predetermined angle by using a two-axis geomagnetic sensor;
• measuring gravity acceleration values of the X and Y axes in the tilted state by using a two-axis acceleration sensor;
• judging that the X or Y axis of the two-axis geomagnetic sensor is perpendicular when the X-axis or Y-axis gravity acceleration value is substantially 1 G, and storing the geomagnetic field value measured in the X or Y axis of the two-axis geomagnetic sensor as a Z-axis geomagnetic field value;
• and
• calculating an azimuth angle by using the geomagnetic field values of three axes so as to compensate the azimuth angle changed by tilt.

A method of compensating tilt comprising:

• measuring geomagnetic field values of the X and Y axes tilted at a predetermined angle by using a two-axis geomagnetic sensor;
• measuring gravity acceleration values of the X and Y axes in the tilted state by using a two-axis acceleration sensor;
• judging that the X axis of the two-axis geomagnetic sensor is perpendicular when the X-axis gravity acceleration value is substantially 1 G, and storing the geomagnetic field value measured in the X axis of the two-axis geomagnetic sensor as a Z-axis geomagnetic field value;
• judging that the Y axis of the two-axis geomagnetic sensor is perpendicular when the Y-axis gravity acceleration value is substantially 1 G, and storing the geomagnetic field value measured in the Y axis of the two-axis geomagnetic sensor as a Z-axis geomagnetic field value;
• and
• calculating an azimuth angle by using the geomagnetic field values of three axes so as to compensate the azimuth angle changed by tilt.

A tilt compensating apparatus comprising:

• a two-axis geomagnetic sensor that measures geomagnetic field values of two axes in a tilted state;
• an acceleration sensor that measures gravity acceleration values in the tilted state;
• and
• a Micom that compares the two-axis geomagnetic field values received from the two-axis geomagnetic sensor with the gravity acceleration values received from the acceleration sensor so that a vertical component of geomagnetic field measured when one axis of the two-axis geomagnetic sensor becomes perpendicular to a horizontal plane of the earth surface is stored as a Z-axis geomagnetic field value, and calculates an azimuth by using the Z-axis value.