Corrugated Beam Accelerometer for High-G Sensing
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Solution Overview
Problem
Current inertial guidance systems, such as those using Resonating Beam Accelerometers (RBAs), face challenges in accurately measuring high levels of acceleration with high sensitivity, especially when detecting small changes or large ranges of acceleration values, which limits their ability to track object position effectively.
Innovation Solution
The development of an electro-opto-mechanical accelerometer system that employs corrugated mechanical beams in double-ended tuning fork (DETF) structures to induce mechanical vibration through modulated optical signals, allowing for precise measurement of acceleration by correlating mechanical vibration frequencies with optical signals and using positive feedback loops to enhance calculation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional accelerometer structures are used, then the device complexity is low, but the measurement precision and sensitivity for high acceleration values deteriorate
Solution Approach 1:
The mechanical beam is segmented into multiple sections with different cross-sectional areas along its length. This segmentation allows different portions of the beam to experience different stress levels, enabling the structure to maintain high sensitivity while withstanding high acceleration forces without exceeding material stress limits.
Solution Approach 2:
The beam is designed with non-uniform cross-sectional properties, where the cross-sectional area varies along the length of the beam. This local quality variation optimizes the stress distribution, allowing the beam to achieve both high measurement precision for small acceleration changes and sufficient strength for high acceleration values.
2Strength
If the mechanical beam cross-sectional area is increased to handle high acceleration, then the strength increases, but the sensitivity to detect small changes in acceleration deteriorates
Solution Approach 1:
The beam is divided into multiple segments with progressively varying cross-sectional areas. This segmentation enables the beam to have higher overall strength to withstand high acceleration while maintaining regions of lower cross-sectional area that provide high sensitivity for detecting small acceleration changes.
Solution Approach 2:
The cross-sectional area parameter of the beam is changed along its length, creating a tapered or stepped profile. This parameter variation allows the beam to optimize both strength and sensitivity by having larger cross-sections in regions requiring higher strength and smaller cross-sections in regions requiring higher sensitivity.
3Measurement precision
If the mechanical beam cross-sectional area is decreased to improve sensitivity, then the measurement precision improves, but the strength to withstand high acceleration deteriorates
Solution Approach 1:
The beam structure is segmented into multiple sections with varying cross-sectional areas. This segmentation allows the beam to have regions with smaller cross-sectional areas for high sensitivity measurement while other regions have larger cross-sectional areas to provide the necessary strength to withstand high acceleration forces.
Solution Approach 2:
Different portions of the beam are designed with different cross-sectional properties tailored to their specific functional requirements. Regions requiring high sensitivity have smaller cross-sections, while regions requiring high strength have larger cross-sections, optimizing both measurement precision and structural integrity.
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 enables the accelerometer system to accurately measure high acceleration values up to 500,000 m/s² with high sensitivity, detecting small changes and large ranges, thereby improving the tracking of object position without separate navigation systems.
Implementation Method 1
employs corrugated mechanical beams in double-ended tuning fork (DETF) structures to induce mechanical vibration through modulated optical signals
Implementation Method 2
The set of mechanical beams are configured to guide a modulated optical signal. The first inner edge and/or the first outer edge are corrugated, and the second inner edge and/or the second outer edge are corrugated.
Implementation Method 3
An RBA senses acceleration via stress-induced frequency shifts of vibrational modes of proof mass anchor beams
Data Source
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AI summary
This disclosure is related to devices, systems, and techniques for inducing mechanical vibration in one or more mechanical structures. For example, a system includes a mechanical structure extending along a longitudinal axis. The mechanical structure includes a set of mechanical beams, where the set of mechanical beams are configured to guide a modulated optical signal, and where the set of mechanical beams includes a first mechanical beam and a second mechanical beam separated by a gap. The first mechanical beam includes at least one of a first corrugated inner edge parallel to the longitudinal axis and a first corrugated outer edge parallel to the longitudinal axis. The second mechanical beam includes at least one of a second corrugated inner edge parallel to the longitudinal axis and a second corrugated outer edge parallel to the longitudinal axis.