Tri-axis angular rate sensor with independent sense frame
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current angular rate sensors require multiple separate sensors and integrated circuits to measure rotation about three mutually perpendicular axes, leading to increased complexity and cost.
Innovation Solution
A tri-axis rate sensor design featuring planar proof masses coupled for linear drive-mode oscillation and a single sense frame that rotates independently about each axis due to Coriolis forces, utilizing comb drive actuators and capacitors to monitor rotation, allowing for simultaneous measurement of rotation about three axes with a single ASIC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three separate rate sensors are used to measure rotation about three mutually perpendicular axes, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The patent combines three separate rate sensing functions into a single integrated sensor device. The proof mass system measures rotation about three mutually perpendicular axes simultaneously, eliminating the need for three separate sensors and their associated integrated circuits, thus reducing device complexity while maintaining full 3-axis measurement capability
Solution Approach 2:
The single rate sensor device performs multiple functions by measuring rotation about all three axes (x, y, and z) simultaneously. The proof mass is coupled to sense frame rotations about all three axes, allowing one device to replace three separate specialized sensors
2Measurement precision
If three separate rate sensors are used, then measurement capability is improved, but manufacturing cost increases
Solution Approach 1:
By merging three separate sensor functions into one integrated device, the patent reduces the total number of components that need to be manufactured, assembled, and tested. This consolidation directly reduces manufacturing cost while maintaining the capability to measure all three axes of rotation
3Stability of the object's composition
If separate sensors are used for each axis, then axis independence is improved, but dynamic coupling increases
Solution Approach 1:
The patent segments the sensing functions for each axis while using a shared proof mass. The sense frame is designed to rotate independently about each of the three axes, allowing the measurement functions to be separated while the mechanical structure remains integrated, thus minimizing dynamic coupling between axes
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 reduces the number of required integrated circuits, minimizes dynamic couplings, and suppresses quadrature errors, resulting in a more efficient and cost-effective angular rate sensor capable of measuring all three components of rotation simultaneously.
Implementation Method 1
means for mounting the sense frame on the substrate for rotation with the masses about the first, second, and third input axes independent of one another in response to Coriolis forces produced by rotation of the masses about the first, second, and third input axes respectively
Data Source
AI summary
Angular rate sensor for detecting rotation about first, second and third mutually perpendicular input axes having a plurality of generally planar proof masses coupled together for linear drive-mode oscillation along multi-directional drive axes in a plane formed by the first and second input axes. The masses are mounted on a generally planar sense frame for linear movements relative to the sense frame in drive-mode and for rotation together with the sense frame in sense modes. The sense frame is mounted for rotation with the masses in sense modes about the first, second, and third input axes independent of each other, in response to Coriolis forces produced by rotation of the masses about the first, second, and third input axes respectively. And capacitance sensors responsive to the rotational movements of the masses and the sense frame in sense modes are employed for monitoring rate of rotation.