Coriolis effect transducer

• US 6,516,651 B1
• Filed: 07/22/1999
• Issued: 02/11/2003
• Est. Priority Date: 07/22/1999
• Status: Expired due to Term

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Geen, John Albert
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US09/359,477
• Time in Patent Office: 1,300 Days
• Field of Search: 73/11.6, 738/613.54, 738/613.55, 738/613.56, 738/613.57, 73/12.7, 73/13.4, 735/040.2, 735/040.4, 73/13.8
• US Class Current: 73/1.16
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01F 1/8445 micromachined flowmeters
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, F_{TEST VIBRATORY} and F_{TEST SENSITIVE} are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output V_{OUT TEST} of the transducer is measured in response to the forces, F_{TEST VIBRATORY} and F_{TEST SENSITIVE}.

Claims

1. A method for testing a Coriolis transducer having a mass vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a rate sensing axis, such displacement being perpendicular to both the vibration and the rate sensing axis, such method comprising:

applying forces, F_{TEST VIBRATORY} and F_{TEST SENSITIVE}, on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N; and

,

measuring an incremental output V_{OUT TEST} of the transducer in response to the forces, F_{TEST SENSITIVE} and F_{TEST VIBRATORY}.

2. The method recited in claim 1 wherein the mass is included in a resonant structure and the method includes measuring a characteristic frequency of the resonant structure.

3. The method recited in claim 2 wherein the resonant structure is a second-order resonant structure having an amplitude characteristic related to:

4. The method recited in claim 2 wherein the characteristic frequency of the resonant structure is determined by applying a known vibratory frequency, or frequencies, to the mass within the resonant structure.