Method of calibrating a heading reference system
AssigneeInnovative Solutions & Support, Inc.
InventorShahram Askarpour
Life of this patent
Estimating the term…
Abstract
A method of calibrating 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 involves 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 which are then averaged to obtain a universal average gain and offset for the magnetometer. 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.
Claims23
A method for calibrating an aircraft attitude and reference heading system for an aircraft while positioned on the ground along the Earth's surface, said heading system having an associated attitude for said positioned aircraft and comprising a magnetometer, said method comprising the steps of:
- obtaining an actual reading from said magnetometer at a selected magnetic heading for said positioned aircraft;
- obtaining a set of theoretical magnetic field properties of the Earth at the location of said positioned aircraft, said obtained theoretical magnetic field properties comprising theoretical values for a horizontal intensity and a vertical intensity of said magnetic field at said location of said positioned aircraft;
- computing a theoretical reading for said magnetometer at said selected magnetic heading of said positioned aircraft based on at least said magnetic heading, said associated attitude for said positioned aircraft, and said obtained theoretical values for said magnetic field at said location of said positioned aircraft;
- comparing said obtained actual magnetometer reading for said positioned aircraft at said selected magnetic heading with said obtained theoretical magnetometer reading at said selected magnetic heading for providing a calibration value for said heading system at said selected magnetic heading for said positioned aircraft;
- and utilizing said provided calibration value at said magnetic heading of said aircraft for providing a universal average gain and offset for said magnetometer;
- whereby said heading system is universally calibrated with respect to measurement errors.
A method for calibrating a heading system for a vehicle while positioned along the Earth's surface, said heading system comprising a magnetometer, said method comprising the steps of:
- obtaining an actual reading from said magnetometer at a selected magnetic heading for said positioned vehicle;
- obtaining a set of theoretical magnetic field properties of the Earth at the location of the positioned vehicle, said obtained theoretical magnetic field properties comprising theoretical values for a horizontal intensity and a vertical intensity of said magnetic field at said location of said positioned vehicle;
- computing a theoretical reading for said magnetometer at said selected magnetic heading of said positioned vehicle based on at least said magnetic heading and said obtained theoretical values for said magnetic field at said location of said positioned vehicle;
- comparing said obtained actual magnetometer reading for said positioned vehicle at said selected magnetic heading with said obtained theoretical magnetometer reading at said selected magnetic heading for providing a calibration value for said heading system at said selected magnetic heading for said positioned vehicle;
- and
- utilizing said provided calibration value at said magnetic heading of said vehicle for providing a universal average gain and offset for said magnetometer;
- whereby said heading system is universally calibrated with respect to measurement errors.
Dependencies are inferred from the claim text.