Angular Velocity Sensor Mass Body Displacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing angular velocity sensors have limited detection sensitivity due to restricted displacement of the mass body, which restricts the amplitude of vibration and consequently the Coriolis force and capacitance change, making them less effective in detecting angular velocity.
Innovation Solution
The design includes a mass body that can displace in a direction intersecting the main surface with a longer distance between the base body and the mass body, allowing for larger vibration displacement and increased Coriolis force, and incorporates a thicker detection working electrode and a detection fixed electrode to enhance capacitance change detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the mass body is driven by vertical vibration to increase displacement, then the detection sensitivity is improved, but the interval between the support base body and the mass body decreases, limiting the maximum displacement amplitude
Solution Approach 1:
The patent repositions the mass body from a configuration where it moves parallel to the base body to one where it moves in a direction intersecting the main surface of the base body. This dimensional change allows the mass body to achieve larger displacement amplitudes without reducing the interval d1, as the movement occurs in a different spatial dimension relative to the base body surface.
Solution Approach 2:
The patent introduces asymmetry in the electrode configuration by setting d1 > d2, where d1 is the distance between the base body and mass body, and d2 is the distance between the base body and detection fixed electrode. This asymmetric arrangement optimizes both the vibration displacement capability and the capacitance detection sensitivity simultaneously.
2Measurement precision
If the interval between the base body and mass body is reduced to increase capacitance change, then the detection sensitivity is improved, but the mass body displacement is restricted
Solution Approach 1:
The patent changes the vibration direction to intersect the main surface of the mass body, allowing large displacement in a different dimension while maintaining a sufficient interval d1. This resolves the conflict between needing large displacement for sensitivity and maintaining interval for capacitance detection.
Solution Approach 2:
The patent applies different distance requirements to different parts of the system: d1 (base body to mass body) is made larger to allow displacement, while d2 (base body to detection fixed electrode) is made smaller to enhance capacitance detection. This local differentiation of spatial parameters optimizes both functions simultaneously.
3Measurement precision
If the mass body displacement amplitude is increased to improve Coriolis force, then the angular velocity detection sensitivity is improved, but the structural design becomes more complex
Solution Approach 1:
The patent simplifies the structural design by changing the vibration direction to intersect the main surface, which naturally enables larger displacement amplitudes without requiring complex mechanical structures. This dimensional approach achieves large amplitude motion more simply than traditional parallel movement configurations.
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 configuration results in a functional element with higher detection sensitivity for angular velocity, enabling more accurate detection of internal surface axis rotation by increasing the vibration displacement and capacitance change between electrodes.
Implementation Method 1
a drive electrode provided on a surface side that faces the mass body of the first base body
Implementation Method 2
angular velocity of an internal surface axis rotation is detected by a change of a capacitance which is generated between a working electrode which extends from the mass body, and a fixed electrode which is disposed on a support substrate
Implementation Method 3
angular velocity of axis rotation in a direction along the main surface of the mass body is applied, the mass body is vibrated in another direction along the main surface by Coriolis force
Data Source
AI summary
A functional element includes a first base body; a coupling section which is coupled to the first base body; a support body which extends from the coupling section; a mass body which is coupled to the support body; a drive electrode which is provided on a surface side that faces the mass body; a detection working electrode which extends from the support body; and a detection fixed electrode which is coupled to the first base body and faces at least a portion of the detection working electrode. The mass body can be displaced in a direction which intersects a main surface of the mass body. When a distance between the first base body and the mass body is referred to as d1 and a distance between the first base body and the detection fixed electrode is referred to as d2, a relation of d1>d2 is satisfied.