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);
John C. Baker, Santa Barbara, CA (US);
Daniel T. Zaida, Goleta, CA (US);
Patrick A. Toole, Santa Barbara, CA (US);
Litton Systems, Inc., Woodland Hills, CA (US);
Abstract
A time based digital to analog converter is presented in which known reference voltages are used to create variable period waveforms which, when combined according to a desired computation, can convert digital words into a sinusoidal signal of a precision variable. To illustrate the application of the present invention, a hemispherical resonator gyroscope (HRG) operating in force rebalance is presented wherein a time based digital to analog converter with a variable period output controls the HRG electronics in nulling the standing wave. A rate of the standing wave is calculated, and a software component calculates the fraction of the maximum rate needed to oppose and null the initial rate of the standing wave. The fraction of the maximum rate is converted to digital words corresponding to the number of periods of a clock connected to the circuit. Using the digital words thus determined, a gate array using digital logic generates waveforms having variable periods, where the amplitude of the waveforms correspond to fixed reference voltage sources, and the period of the waveforms are determined by the digital words in the earlier calculation. Using the waveforms, the HRG rate controls can be maintained at a high level of precision.