US 6,651,003 B2 · Method of automatic continuous calibration for an electric compass

Abstract

An autocalibration method for use within an electronic compass in a vehicle is disclosed. The method includes steps of initializing variables and then retrieving sensor readings from at least two axis. The method then compares the compass tilt to a predetermined threshold. Next the method will determine if the sensor reading is a minimum or maximum for the current calibration cycle. Next the method will determine if the maximum value of the sensor readings is greater than the predetermined minimum spread. Then the method will calculate an offset value for each axis and calculate a sensor value for each axis. Then the method will calculate an azimuth value with the new sensor values and determine the heading using the azimuth.

Claims18

Dependent claims

An autocalibration method for use with an electronic compass in a vehicle, said method including the steps of:

initializing variables;
retrieving sensor readings from at least two axis;
updating calibration based on said sensor readings;
calculating a raw azimuth wit calibration adjusted sensor readings;
adjusting said raw azimuth by a declination angle;
filtering said raw azimuth with a previously filtered azimuth to obtain a filtered azimuth;
updating a first heading from said filtered azimuth;
and
determining if a display needs said updated first heading transferred thereto.

6 more elements

Dependencies are inferred from the claim text.

Method of automatic continuous calibration for an electric compass

Life of this patent

Method of automatic continuous calibration for an electric compass

Life of this patent

Abstract

Claims18