Temperature-robust MEMS gyroscope with 2-DOF sense-mode addressing the tradeoff between bandwidth and gain

• US 8,656,776 B2
• Filed: 11/01/2012
• Issued: 02/25/2014
• Est. Priority Date: 02/21/2008
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Trusov, Alexander, Schofield, Adam, Shkel, Andrei
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US13/666,494
• Publication Number:
  US 20130074304A1
• Time in Patent Office: 481 Days
• Field of Search: 735/041.2, 735/041.4, 438/50
• US Class Current: 73/504.12
• CPC Class Codes: B23Q 17/00 Arrangements for observing, indicating or measuring on machine tools for automatic control or regulation of feed movement, cutting velocity or position of tool or work B23Q15/00
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: Y10T 29/49764 with testing or indicating
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

The current invention is a novel gyroscope design, which yields devices robust to fabrication and environmental variations, allows flexible selection of operational parameters, and provides increased bandwidth with minimized sacrifice in gain regardless of the selected frequency of operation. The gyroscope has a single degree-of-freedom (DOF) drive-mode and a 2-DOF sense-mode. The drive-mode operational frequency and the sense-mode bandwidth can be selected arbitrarily in the proposed design, relaxing the tradeoff between the gain, die size, and detection capacitance. The symmetry of the structure ensures the optimal location of the drive-mode resonance relative to the sense-mode operational region, even in presence of fabrication imperfections.

Claims

1. A method of manufacturing a 3-DOF dynamic gyroscopic system which yields implementations to a pre-selected operational frequency and sense-mode peak spacing comprising:

selecting two drive-mode shuttles, two sense-mode shuttles, a detection mass, and a proof mass;

calculating the required stiffness of a plurality of suspension elements according to the pre-selected operational frequency and sense-mode spacing; and

coupling the suspension elements to the two drive-mode shuttles, the two sense-mode shuttles, the detection mass, and the proof mass.

2. The method of claim 1 where the two drive-mode shuttles, the two sense-mode shuttles, the detection mass, and the proof mass are selected based on a desired die size and capacitance of the 3-DOF dynamic gyroscope system.

3. The method of claim 1 further comprising ensuring that the operational frequency is optimally located between the sense-mode peaks even in the presence of large fabrication imperfections.