Seesaw Spring Micro-Mechanical Angular Velocity Sensor
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Solution Overview
Problem
Existing angular velocity sensors are susceptible to mechanical interference and capacitive crosstalk, leading to unreliable measurements, especially in small vibrating micro-mechanical sensors, which are prone to disturbances from external impacts and vibrations.
Innovation Solution
A vibrating micro-mechanical sensor design featuring two seismic mass structures supported by seesaw-type springs and excitation comb structures, with differential detection and quadrature motion compensation, minimizing mechanical interference and capacitive crosstalk through a robust and compact spring structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If differential detection with two masses is used, then insensitivity to external mechanical disturbance is improved, but primary motion susceptibility to external disturbances worsens
Solution Approach 1:
The patent applies asymmetry by using seesaw-type springs with different configurations for the first and second seismic masses. The springs are arranged asymmetrically relative to the excitation direction, creating different mechanical coupling characteristics that reduce susceptibility to linear acceleration while maintaining differential detection capabilities.
Solution Approach 2:
The patent transitions from planar motion to three-dimensional motion by allowing the seismic masses to move in directions not confined to the excitation plane. The seesaw-type springs enable out-of-plane motion components, adding dimensional freedom that reduces sensitivity to disturbances in the primary motion direction.
2Volume of moving object
If small vibrating micro-mechanical sensor structure is used, then device size is reduced, but reliability under mechanical interference worsens
Solution Approach 1:
The patent employs dynamic motion patterns where the seismic masses vibrate in opposite phases along directions not parallel to the excitation direction. This dynamic configuration allows the small sensor structure to maintain reliability by exploiting temporal and spatial variations in motion that reduce susceptibility to mechanical interference.
Solution Approach 2:
The patent changes the motion parameters by orienting the vibration directions at specific angles relative to the excitation direction. By adjusting the orientation and phase relationships of the seismic mass motions, the sensor achieves improved reliability in a compact form factor.
3Device complexity
If traditional tuning fork principle is used, then concept simplicity is maintained, but susceptibility to external mechanical interference increases
Solution Approach 1:
The patent inverts the traditional tuning fork principle by having the seismic masses vibrate in directions not parallel to the excitation direction. Instead of linear motion along the excitation axis, the masses move in perpendicular or angled directions, fundamentally changing the detection geometry to reduce susceptibility to mechanical interference.
Solution Approach 2:
The seesaw-type springs act as intermediaries that couple the excitation structures to the seismic masses in a way that filters out mechanical disturbances. The spring mechanism transforms direct mechanical coupling into a more resilient connection that reduces the transmission of external interference to the sensing elements.
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 reliable and efficient measurement of angular velocity perpendicular to the surface plane with reduced sensitivity to mechanical interference and minimized capacitive crosstalk, enhancing performance and reliability in small form factors.
Implementation Method 1
said first springs are seesaw type springs, each of which includes a stiff support structure configured to turn in the surface plane about a fixed axis, and thereby force the excitation structures comprising said at least two seismic mass structures into opposite phase vibration
Implementation Method 2
An external angular velocity affecting the sensor in a direction perpendicular to the direction of motion of the resonators causes Coriolis forces influencing the masses in opposite directions
Data Source
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AI summary
The invention relates to measuring devices used for measuring angular velocity, and more precisely, to vibrating micro-mechanical sensors of angular velocity. The sensor of angular velocity according to the invention comprises at least two seismic mass structures (1), (2), excitation structures (3), (4) and coupling seesaw type springs (6), (7). The objective of the invention is to provide an improved sensor structure, which enables reliable measuring with good efficiency particularly in small vibrating micro-mechanical angular velocity sensor solutions.