MEMS Gyroscope Dual Mass Anti-Phase Vibration Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microelectromechanical devices used for detecting angular motion in demanding conditions, such as automotive applications, face challenges in balancing sensitivity and robustness due to the need for multi-axis configurations that are sensitive yet robust against external vibrations.
Innovation Solution
A microelectromechanical device design featuring two oscillating inertial masses coupled in a balanced structure that optimally utilizes the inherent stiffness of spring structures to enhance robustness, enabling multi-axis detection with anti-phase rotational motion and differential detection modes to reduce measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-axis configurations are used to enable detection in multiple directions, then adaptability is improved, but robustness against external vibrations deteriorates
Solution Approach 1:
The device segments the detection function into two separate inertial masses, each optimized for specific detection axes. The first inertial mass detects angular rates about the first axis, while the second inertial mass detects angular rates about the second axis. This segmentation allows each mass to be independently optimized, improving overall adaptability while maintaining robustness through balanced configuration.
Solution Approach 2:
The patent employs a balanced structure where the two inertial masses are configured to move in anti-phase. The center of mass of the system is positioned at the support point, creating a counterbalanced configuration. This anti-weight principle ensures that vibrations and external disturbances affecting one mass are compensated by the other, significantly improving robustness against external vibrations while maintaining multi-axis detection capability.
2Measurement precision
If sensitivity is increased to improve measurement precision, then measurement precision is improved, but robustness against external vibrations deteriorates
Solution Approach 1:
The balanced structure with counterweights positioned to create anti-phase motion between the two inertial masses provides inherent vibration rejection. The center of mass is located at the support point, creating a seesaw configuration where external vibrations are naturally compensated. This allows the system to maintain high sensitivity to rotational motion while being robust against external disturbances.
Solution Approach 2:
Instead of using a single inertial mass that is highly sensitive but vulnerable to vibrations, the patent inverts the approach by using two masses that move in opposite directions. The anti-phase motion creates differential detection where the desired Coriolis signals add constructively while vibration signals cancel out, achieving both high measurement precision and robustness simultaneously.
3Ease of operation
If spring structures are made more flexible to enable oscillation, then ease of operation is improved, but robustness against external vibrations deteriorates
Solution Approach 1:
The spring structures connecting the inertial masses to the support are configured in a balanced, counterweighted arrangement. When one mass oscillates, the other oscillates in anti-phase, creating a seesaw motion. This configuration allows the springs to be sufficiently flexible to enable the required oscillation ranges while the counterbalancing effect of the two masses provides natural vibration isolation, maintaining robustness against external vibrations.
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 design provides a robust and sensitive multi-axis gyroscope capable of operating effectively in challenging conditions by minimizing undesired vibrations and maintaining accurate angular rate measurements.
Implementation Method 1
Microelectromechanical (MEMS) gyroscopes use the Coriolis Effect to measure the angular rate. When a mass is moving in one direction and rotational angular velocity is applied, the mass experiences a force in orthogonal direction as a result of the Coriolis effect.
Implementation Method 2
The device structure includes first and second spring systems, each configured to enable oscillating motion of the first and second inertial masses, respectively
Data Source
AI summary
An improved design for a microelectromechanical device that enables multi-axis detection but is also more robust in demanding operating conditions. The device has a balanced structure formed of two oscillating inertial masses, coupled in a way that optimally utilizes inherent stiffnesses of spring structures to increase robustness of the combined device structure.