Piezoelectric Ring Gyroscope With Split Transducers for Precise Sensing
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Solution Overview
Problem
Existing microelectromechanical systems (MEMS) gyroscopes face challenges in detecting angular rotation rates due to small detection capacitances and limited space for transducers, which affects the accuracy and compatibility with standard packaging requirements.
Innovation Solution
The use of piezoelectric transducers to drive and detect the primary and secondary resonance modes in a ring gyroscope, along with the attachment of mass elements and specific suspension structures to optimize resonance properties and signal strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitive transducers are used to detect angular rotation rates in MEMS gyroscopes, then the device can be manufactured with standard packaging, but the detection capacitance is small which limits measurement precision
Solution Approach 1:
The transducer system is divided into multiple segments: drive transducers for exciting primary oscillation, sense transducers for detecting secondary oscillation, and mass elements strategically positioned around the ring. This segmentation allows each component to be optimized independently for its specific function, improving overall measurement precision without excessive complexity
Solution Approach 2:
The patent transitions from planar capacitive transducers to three-dimensional piezoelectric transducers with mass elements attached at specific spatial positions around the ring. This dimensional change enables stronger coupling between the transducers and the ring, increasing detection sensitivity and signal strength while maintaining compatibility with standard packaging
2Measurement precision
If the ring structure is optimized for resonance oscillation, then the signal-to-noise ratio improves, but the space available for transducer placement is limited
Solution Approach 1:
Mass elements are nested within or attached to the ring structure at specific positions, allowing the transducers to be integrated into the existing ring geometry rather than adding external components. This nesting approach maximizes the use of available space while maintaining resonance properties and improving signal-to-noise ratio
Solution Approach 2:
The patent utilizes the vertical dimension by attaching mass elements and piezoelectric transducers above and below the ring plane, rather than only in the planar direction. This three-dimensional configuration increases the effective transducer placement area and coupling strength without interfering with the ring's resonance oscillation
3Measurement precision
If piezoelectric transducers with mass elements are used, then detection accuracy improves, but manufacturing complexity increases
Solution Approach 1:
The drive transducers, sense transducers, and mass elements are merged into a single integrated assembly that is attached to the ring as one unit. This combining of components simplifies the manufacturing process by reducing the number of separate assembly steps, despite the increased complexity of the individual components
Solution Approach 2:
The piezoelectric transducer assembly serves multiple functions simultaneously: it provides both drive and sense capabilities, and the mass elements contribute to both resonance tuning and detection sensitivity. This multi-functionality reduces the need for separate components, thereby simplifying manufacturing while maintaining high detection accuracy
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the signal-to-noise ratio and reduces errors, improving the accuracy of angular rotation rate detection while being compatible with standard silicon device packaging.
Implementation Method 1
at least one primary piezoelectric split transducer...drive the ring into resonance oscillation
Implementation Method 2
When a ring in drive oscillation undergoes an angular rotation rate Ω about the z-axis...the ring is affected by the Coriolis force FC...The oscillation caused by the Coriolis force in the ring will be called 'secondary oscillation' or 'sense oscillation'
Implementation Method 3
one or more secondary piezoelectric split transducers...sense the oscillation of the ring...placed on one or more second sectors of the ring
Implementation Method 4
drive the ring into resonance oscillation...primary resonance mode...secondary resonance mode
Data Source
AI summary
A ring gyroscope which comprises a substantially circular and flexible ring which defines a ring plane, one or more primary piezoelectric split transducers configured to drive the ring into resonance oscillation, four or more mass elements which form a symmetrical mass distribution in relation to both a first and a second transversal symmetry axis and to a first and a second diagonal symmetry axis. The ring gyroscope also comprises a suspension structure configured to support the weight of the ring and the mass elements, wherein the suspension structure comprises N outer suspenders, where N is an integer greater than or equal to two, and each outer suspender extends along a ring tangent from a suspension attachment point on the outer edge of the ring to an anchor point.