Angular Oscillation Micro-Mechanical Sensor for Vibration Resistance
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Solution Overview
Problem
Existing angular velocity sensors are highly sensitive to mechanical interference, such as vibrations and impacts, which cause deviations in output signals due to their sensitivity to external linear accelerations and lack of resistance to external forces.
Innovation Solution
The design incorporates two seismic masses connected by a bending spring, with rotary and torsion springs providing flexibility for primary and detection motions, and capacitive detection using electrodes, while attachment spots and auxiliary structures enhance stability and reduce interference sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sensor uses tuning fork principle with linear resonators, then the structure is simple and reliable, but the detection motion is highly sensitive to external linear accelerations and mechanical interference
Solution Approach 1:
The patent inverts the traditional tuning fork approach by using angular oscillation for both primary motion and detection motion. Instead of using linear resonators that are sensitive to linear accelerations, the invention employs a disk structure that oscillates angularly, making the detection motion an angular oscillation that is inherently less sensitive to external linear accelerations and mechanical interference.
Solution Approach 2:
The patent changes the fundamental motion parameter from linear oscillation to angular oscillation. By transforming the primary motion and detection motion both into angular oscillations about different axes, the sensor achieves reduced sensitivity to mechanical interference while maintaining the simplicity of the oscillating principle.
2Object-affected harmful factors
If the primary motion is angular oscillation about axis z in the plane of the disk, then the primary motion is less sensitive to linear accelerations, but the primary motion is clearly less sensitive to external forces than the detection motion
Solution Approach 1:
The patent employs asymmetric attachment of seismic masses at different locations on the disk (different radial distances and angular positions). This asymmetric configuration creates different moments of inertia and sensitivity characteristics for different axes, allowing the primary motion axis to be less sensitive to linear accelerations while the detection axis maintains high sensitivity to angular velocity.
Solution Approach 2:
The patent utilizes three-dimensional angular oscillation about different axes (primary motion about axis z, detection motion about axis x or y). By operating in different dimensional orientations, the sensor achieves differential sensitivity where the primary motion is protected from linear accelerations while the detection motion remains sensitive to angular velocity changes.
3Volume of moving object
If the sensor structure is compact, then the device size is reduced, but the resistance to vibration and impact becomes more difficult to achieve
Solution Approach 1:
The patent merges the primary motion structure and detection structure into a single integrated disk assembly with seismic masses. The same disk serves both as the primary oscillating element and as the detection element, eliminating the need for separate structures and achieving compact size while maintaining vibration resistance through the angular oscillation principle.
Solution Approach 2:
The disk structure performs multiple functions simultaneously: it provides the primary angular oscillation, houses the seismic masses, enables detection motion through angular displacement, and resists mechanical interference. This multi-functionality reduces the overall sensor size while maintaining reliability against vibration and impact.
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
The sensor achieves improved resistance to mechanical interference, maintaining signal accuracy by minimizing the impact of external vibrations and impacts, and allows for efficient detection of angular velocity with reduced sensitivity to common mode motions.
Implementation Method 1
The seismic masses are connected to each other by means of at least one bending spring, mechanically synchronizing their primary motion
Implementation Method 2
The seismic masses are attached to the support areas by means of springs or by means of springs and stiff auxiliary structures
Implementation Method 3
the oscillation caused by the external angular velocity is capacitively detected by means of electrodes located above or underneath the masses
Implementation Method 4
An external angular velocity affecting the sensor in a direction perpendicular to the direction of motion of the resonators induces Coriolis forces on the masses in opposite directions
Data Source
AI summary
The invention relates to measuring devices used in measuring angular velocity, and, more specifically, to oscillating micro-mechanical sensors of angular velocity. In the sensor of angular velocity according to the present invention seismic masses (1), (2), (36), (37) are connected to support areas by means of springs or by means of springs and stiff auxiliary structures, which give the masses (1), (2), (36), (37) a degree of freedom in relation to an axis of rotation perpendicular to the plane of the wafer formed by the masses, and in relation to at least one axis of rotation parallel to the plane of the wafer. The structure of the sensor of angular velocity according to the present invention enables reliable and efficient measuring particularly in compact oscillating micro-mechanical sensors of angular velocity.