MEMS Inertial Sensor Decoupling Acceleration and Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MEMS inertial measurement units require multiple gyroscopes and accelerometers, leading to increased size, computational requirements, power consumption, and cost, necessitating a reduction in the number of sensing devices while maintaining the ability to independently determine acceleration and rotation.
Innovation Solution
A MEMS inertial sensor design that decouples acceleration and rotation sensing using a configuration of proof masses and electrode pairs, allowing for the independent detection of in-plane and out-of-plane linear acceleration and rotation by utilizing interleaved comb fingers and drive electrodes to sense changes in capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three gyroscopes and three accelerometers are used to detect changes in attitude and acceleration, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by enabling a single MEMS device to perform both accelerometer and gyroscope functions. The device uses proof masses that can detect both linear acceleration (accelerometer function) and angular rotation (gyroscope function) through the same mechanical structure, eliminating the need for separate sensing devices for each function.
Solution Approach 2:
The patent combines multiple sensing functions into a single integrated MEMS device. By merging the accelerometer and gyroscope functionalities into one device with shared proof masses and electrode structures, the patent reduces the total number of components while maintaining the capability to measure both linear acceleration and angular rotation.
2Measurement precision
If three gyroscopes and three accelerometers are mounted on separate orthogonal axes, then measurement precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent combines multiple sensing functions into a single integrated MEMS device. By merging the accelerometer and gyroscope functionalities into one device with shared proof masses and electrode structures, the patent reduces the total number of components while maintaining the capability to measure both linear acceleration and angular rotation.
Solution Approach 2:
The patent segments the sensing functions along orthogonal axes within a single device structure. The proof masses are configured to respond to accelerations and rotations along different axes, allowing the device to capture three-dimensional motion information through coordinated measurements from the segmented sensing elements.
3Measurement precision
If six separate sensing devices are used, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent applies multi-functionality by enabling a single MEMS device to perform both accelerometer and gyroscope functions. The device uses proof masses that can detect both linear acceleration (accelerometer function) and angular rotation (gyroscope function) through the same mechanical structure, eliminating the need for separate sensing devices for each function.
4Measurement precision
If six separate sensing devices are used, then measurement precision is improved, but computational requirements increase
Solution Approach 1:
The patent applies multi-functionality by enabling a single MEMS device to perform both accelerometer and gyroscope functions. The device uses proof masses that can detect both linear acceleration (accelerometer function) and angular rotation (gyroscope function) through the same mechanical structure, eliminating the need for separate sensing devices for each function.
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 enables the reduction of components in MEMS inertial measurement units, reducing size, computational needs, and power consumption while allowing for precise determination of both acceleration and rotation, thereby addressing the constraints of existing systems.
Implementation Method 1
sensing changes in capacitance
Implementation Method 2
convert electrical energy into mechanical energy using electrostatic actuation
Implementation Method 3
measuring Coriolis forces exerted on resonating proof masses
Implementation Method 4
convert electrical energy into mechanical energy using electrostatic actuation
Implementation Method 5
cause the proof mass to oscillate back and forth
Data Source
AI summary
A Micro-Electro-Mechanical Systems (MEMS) inertial sensor systems and methods determine linear acceleration and rotation in the in-pane and out-of-plane directions of the MEMS inertial sensor. An out-of-plane linear acceleration of the MEMS sensor may be sensed with the first out-of-plane electrode pair and the second out-of-plane electrode pair. An in-plane rotation of the MEMS sensor may be sensed with the first out-of-plane electrode pair and the second out-of-plane electrode. An in-plane linear acceleration of the MEMS sensor may be sensed with the first in-plane sense comb and the second in-plane sense comb. An out-of-plane rotation of the MEMS sensor may be sensed with the first in-plane sense comb and the second in-plane sense comb.