Oblique Spring Resonator for Angular Velocity Sensor
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Solution Overview
Problem
Existing angular velocity sensors in the automotive industry face challenges in distinguishing between in-phase and out-of-phase motions, leading to sensitivity to linear acceleration and mechanical interferences, which affects the accuracy and robustness of the sensors.
Innovation Solution
A spring structure comprising stiff beams and oblique springs that twist around a support point, with a U-shaped loop substructure and oblique springs connected to anchors, is designed to decouple in-phase motion while maintaining stiffness in the out-of-phase direction, reducing the impact of linear acceleration and mechanical interferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a simple coupling spring structure is used to separate common mode motion from differential motion, then the structure efficiently separates the motions, but the masses deflect more easily in-phase than out-of-phase due to lower frequency, resulting in high sensitivity to linear acceleration
Solution Approach 1:
The spring structure is divided into multiple functional segments: primary springs (S1, S2) for supporting masses, a coupling spring (S3) for differential motion coupling, and additional springs (S4, S5) for restraining in-phase motion. Each segment has a specific function that collectively solves the contradiction by separating common mode restraint from differential motion enablement.
Solution Approach 2:
Different regions of the spring structure have different stiffness properties tailored to specific functions. The coupling spring region allows compliant differential motion while the in-phase restraint springs provide stiffness against common mode deflection. This local differentiation of mechanical properties enables simultaneous achievement of motion separation and acceleration rejection.
2Reliability
If spring structures participate in both primary and secondary modes, then they define frequencies of both modes, but this makes it difficult to control non-linearity of the primary mode and increases sensitivity to mechanical interferences
Solution Approach 1:
The function of restraining in-phase motion is extracted from the primary spring structure and implemented by separate dedicated springs (S4, S5). This separation allows the primary springs (S1, S2, S3) to focus on supporting and coupling differential motion without the complicating non-linear effects of in-phase restraint, thereby simplifying non-linearity control while maintaining frequency definition.
3Object-affected harmful factors
If a seesaw-like coupled spring structure is used to increase stiffness to in-phase deflection, then mechanical interference resistance is improved, but the structure takes up a great amount of space between the masses
Solution Approach 1:
The spring restraint mechanism is transitioned from a lateral seesaw-like configuration to a vertical arrangement where springs (S4, S5) extend upward from the masses to support structures. This dimensional change provides the necessary in-phase stiffness without occupying horizontal space between the masses, thus resolving the space constraint while maintaining interference resistance.
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 enhances the sensors' resistance to mechanical interferences and vibrations, allowing for more accurate detection of out-of-phase oscillations while minimizing the impact of in-phase motions, thus improving the overall robustness and accuracy of the angular velocity sensors.
Implementation Method 1
One end of a first oblique spring is connected directly in the first coupling point to the first spring and to the first branch of the U-shaped loop, and the other end of the first oblique spring is connected directly to a first anchor of the base, and the first oblique spring yields at an oblique angle in relation to the first direction and perpendicularly to its own longitudinal axis
Data Source
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AI summary
The invention presents a spring structure (501), which has at least two masses (Ma, Mb) coupled in a first direction as opposite phase oscillators by means of springs (Sh1, Sh2) connected to them (Ma, Mb), via a loop (L, E) between said springs (Sh1, Sh2) connected to their coupling points, wherein oblique springs (SI45, Sr45) are connected from said coupling points of the loop (L) to the anchors (A) of the base such that the longitudinal motion of the loop (L) is arranged to occur perpendicularly or substantially perpendicularly to said first direction, to thus attenuate opposite phase oscillation other than that of the masses (Ma, Mb). The invention also presents the use of a spring structure in a resonator and/or in a resonator array as well as in a sensor or a sensor comprising system.