The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2001
Filed:
Nov. 05, 1999
Gregory M. Johnson, Goleta, CA (US);
Litton Systems, Inc., Woodland Hills, CA (US);
Abstract
A vibratory sensor, such as for example a hemispherical resonator gyroscope (HRG) operating in the whole angle mode, is disclosed with a self-calibrating function and an improved precision. Precision is improved using two multiplying low noise DACs to estimate the position of the standing wave relative to a fixed position on the HRG. During a first half cycle the DACs multiply a measured standing wave position by an estimated standing wave position, such that the product of the two signals approach zero. The small voltage output can then be amplified using high gain to minimize the noise in the standing wave angle prediction. Using an ADC, the amplified signal is converted and transmitted to a microprocessor for evaluation. In the second half cycle, the low noise multipliers are evaluated using a known reference signal, where the product of the known reference signal and the multipliers are evaluated against a predicted signal to determine multiplier drift. Subsequently, future estimations of the standing wave precess angle are processed using the evaluation of the multipliers, thereby establishing a self-calibration mode.