Geometrical instruments – Indicator of direction of force traversing natural media – Magnetic field responsive
Patent
1995-06-01
1997-05-27
Fulton, Christopher W.
Geometrical instruments
Indicator of direction of force traversing natural media
Magnetic field responsive
33333, 33356, 324252, G01C 1728, G01R 3306
Patent
active
056320922
ABSTRACT:
An electronic compass is described for use in vehicles. The compass employs a magnetoresistive sensor for sensing the earth magnetic field and the sensor is operated in alternate set/reset bias modes. In a first embodiment, the compass is provided with deviation compensation by a closed loop system including measurement of the sensor output signals and an offset current strap for nullifying the vehicle deviation field. In a second embodiment, deviation compensation is provided by operation in an initial calibration mode and by operation in a normal calibration mode to adjust compensation, as needed, on a long term basis during normal operation of the compass. In the initial calibration mode, while the vehicle is being driven, the signal peak values are adjusted to a nominal earth field level by changing the offset current. Then, compensating signal reference values for each axis are determined as each peak for that axis is determined. The system automatically exits the initial calibration mode when certain criteria have been met. In the normal compensation mode, The signal reference value for each axis is adjusted at least once during the time interval between turn-on and turn-off of the vehicle ignition switch.
REFERENCES:
patent: 4309828 (1982-01-01), Sakamoto
patent: 4581827 (1986-04-01), Higashi
patent: 4953305 (1990-09-01), Van Lente et al.
patent: 5124648 (1992-06-01), Webb
patent: 5170566 (1992-12-01), Fowler et al.
patent: 5255442 (1993-10-01), Schierbeek et al.
Blank Rodney K.
Gahan Richard J.
Haselhuhn, Jr. Howard J.
Schierbeek Kenneth L.
Schofield Kenneth
Donnelly Corporation
Fulton Christopher W.
LandOfFree
Compensation system for electronic compass does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compensation system for electronic compass, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compensation system for electronic compass will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2321135