Vibrating Beam Resonator Isolation for Precise Accelerometers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vibrating beam accelerometers face measurement errors due to axial strain on mounting pads caused by the movement of elongated beams, leading to reduced accuracy and precision in sensing acceleration and orientation.
Innovation Solution
The implementation of segmented isolation blocks between mounting pads and resonating tines in the resonator design helps reduce axial strain and end-pumping, enhancing the accuracy and precision of acceleration measurements by balancing lateral movement and minimizing longitudinal strain on the mounting pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If elongated beams are used in the resonator, then the accelerometer can detect acceleration through resonant frequency changes, but axial strain on mounting pads causes measurement errors and reduces accuracy
Solution Approach 1:
The resonator is divided into separate components: elongated beams, mounting pads, and isolation blocks. This segmentation isolates the axial strain effects to specific regions (isolation blocks) while protecting the mounting pads from strain during beam resonance, thereby maintaining measurement accuracy
Solution Approach 2:
Isolation blocks are introduced as intermediary elements between the elongated beams and mounting pads. These blocks absorb and isolate the axial strain generated by beam resonance, preventing it from transferring to the mounting pads and causing measurement errors
2Measurement precision
If resonators are attached to a proof mass, then acceleration can be detected through strain measurement, but end-pumping effects reduce measurement precision
Solution Approach 1:
The harmful end-pumping effect is extracted and isolated from the main sensing mechanism. The isolation blocks capture and contain the end-pumping effects, separating them from the resonant vibration detection process to maintain measurement precision
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 design improves the accuracy and precision of acceleration measurements by effectively reducing axial strain and end-pumping, leading to lower measurement errors and improved performance in sensing orientation and acceleration.
Implementation Method 1
the oscillating arm is supported by the base and by the added mass, either in a pseudo-dual anchor structure or a single anchor structure. With the above configuration, the acceleration sensor detects a resonant frequency variability of the vibrating body caused by an inertial effect of the added mass under acceleration.
Implementation Method 2
an oscillating arm extended from the base in a beam-like shape, oscillating transversally in a planer direction at a predetermined resonant frequency
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A resonator defining a longitudinal axis that includes a mounting pad, a pad connector, at least one isolation mechanism, and a pair of elongated tines extending in the direction of the longitudinal axis. The isolation mechanism including an outer block defining a first outer end and a second outer end on opposite sides, an inner block defining a first inner end and a second inner end on opposite sides, and a pair of interconnect members, where each respective interconnect member of the pair of interconnect members connects the second outer end to the first inner end. The respective first ends of the pair of elongated tines being connected to the second inner end and the pad connector connects the mounting pad to the first outer end.