SYSTEMS AND METHODS FOR CALIBRATING AND ADJUSTING A HEADING REFERENCE SYSTEM

摘要

Systems and methods of calibrating and adjusting for deviations in a vehicle's heading system, such as the attitude heading and reference system of an aircraft or the heading system of a ship, positioned along the Earth's surface involve calibrating magnetometers for hard iron and misalignment errors using single heading measurements. This can be accomplished by obtaining both actual and theoretical readings for the magnetometer of the heading system, and comparing these values to obtain calibration values for the heading system. The vehicle may be repositioned, such as to North, South, East, and west magnetic headings, with the procedure repeated at each of these headings, and the calibration values averaged, further increasing the accuracy.

主权项

1. A method for recalibrating an aircraft attitude and reference heading system comprising at least one magnetometer, the method comprising the steps of:
selectively positioning an aircraft on the ground along the Earth's surface at a single known magnetic heading; obtaining an actual reading from the at least one magnetometer at the known magnetic heading while the aircraft is stationary on the ground; determining a theoretical reading for the at least one magnetometer at the known magnetic heading based, at least in part, on an attitude value that was determined during an initial calibration of the aircraft; calculating a recalibrated universal average gain and offset based, at least in part, on the actual reading and the theoretical reading; utilizing the recalibrated universal average gain and offset to determine a recalibrated magnetic heading for the aircraft and recalibrate the heading system for measurement errors; determining a misalignment value based, at least in part, on a comparison of the known magnetic heading and the recalibrated magnetic heading; and utilizing the misalignment value to adjust the heading system for misalignment errors.