Calibrating a magnetic compass with an angular rate gyroscope and a global positioning system receiver
Patent 6408251 Issued on June 18, 2002. Estimated Expiration Date: July 29, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A method and apparatus for calibrating an electronic compass of the type having a compass sensor, a calibration table and a display. A computer operating under program control is used to update the calibration table of the electronic compass in response to physical movement of at least the electronic compass sensor and an angular rate gyroscope through a 360 degree movement. A pointing device associated with the electronic compass is initially directed to a known landmark position and is also directed to the known landmark position after completing the 360 degree movement. The computer utilizes global positioning system receiver, the known landmark position and a heading provided by the sensor to generate a correction value. The output of the sensor is compared with data generated based upon the gyroscope during the 360 degree movement to generate correction values for other compass headings. The correction values are transmitted to the electronic compass for updating its calibration table.
Other References
"Digital Low-Pass Filter without Phase Shift," NASA Tech Briefs KSC -11471, John F. Kennedy Space Center, Florida
William H. Press et al., "Numerical Recipes in C," The Art of Scientific Computing, Cambridge Univ. Press, pp. 309-317 (1988
July 29, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
