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:
Sep. 08, 1998
Filed:
Nov. 08, 1996
Belvin S Freeman, Asheville, NC (US);
Schlumberger Industries, Inc., Norcross, GA (US);
Continuum Technology Corp., Fletcher, NC (US);
Abstract
A Coriolis-type fluid flow rate measuring system uses phase locked loop-based signal processing to estimate a tube vibration signal and maintain optimum tube vibrations. Analog sinusoidal sensor signals from the flow meter are digitized and processed through heterodyne mixing as part of phase locked loop tracking of the fundamental vibration or oscillation frequency. Digital signal processing is used to implement filtering and signal manipulation so as to respectively determine phase and frequency estimates for both of the two digitized signals. Frequency estimate data is used to adjust the tracker frequency mixed with the respective sensor signals. Digitally obtained phase and frequency estimate data are used to determine an optimized drive signal for continuing tube vibration. Phase estimate information for the two respective sensor signals is used to determine phase shift data, used in turn to determine a fluid flow rate through the flow meter.