Bidirectional Waveguide Gyroscope for Compact 3-Axis Rotation Sensing
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Solution Overview
Problem
Conventional MEMS sensors are susceptible to shocks, vibrations, and temperature changes due to their mechanical components, while chip-integrated optical sensors face challenges in compact, precise three-axis rotation rate determination.
Innovation Solution
A sensor unit utilizing a waveguide with a beam splitter to direct light in both directions, combined with a Coriolis mass element and Mach-Zehnder interferometers, enabling precise measurement of rotation rates in multiple axes using the Sagnac effect and optomechanical coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MEMS sensors are used for rotation rate measurement, then mechanical components provide structure, but they become susceptible to shocks, vibrations, and temperature changes
Solution Approach 1:
The patent replaces mechanical rotation detection with optical measurement principles. A light source emits light through a waveguide, and a photodetector measures light intensity changes caused by the Sagnac effect during rotation, eliminating mechanical components that are susceptible to shocks, vibrations, and temperature changes.
Solution Approach 2:
The patent introduces an optical intermediary system (light source, waveguide, photodetector) to measure rotation rates. The optical path acts as a mediator between the rotation motion and the measurement signal, converting mechanical rotation into optical phase changes that can be detected without direct mechanical contact.
2Volume of moving object
If chip-integrated optical sensors are used for compact size, then unit cost and size are reduced, but precise three-axis rotation rate determination becomes difficult
Solution Approach 1:
The patent divides the rotation measurement into separate axis measurements. By using a waveguide configured to detect rotation rates in different spatial directions and combining signals from multiple detection points, the system achieves precise three-axis rotation rate determination while maintaining compact chip-integrated size.
Solution Approach 2:
The patent transitions from single-axis rotation detection to multi-axis rotation detection by utilizing the waveguide's spatial configuration and optical path geometry. The system measures rotation rates in multiple spatial directions simultaneously by analyzing light intensity changes at different detection points along the waveguide.
3Measurement precision
If conventional optical gyroscopes are used for rotation measurement, then one axis of rotation can be measured, but compact chip-integration with small installation space is limited
Solution Approach 1:
The patent merges multiple optical detection functions into a single integrated waveguide structure. The waveguide serves both as the optical path and as the sensing element, combining the functions of light transmission, rotation detection, and signal generation into one compact component that requires minimal installation space.
Solution Approach 2:
The waveguide structure performs multiple functions simultaneously: it guides light from the light source, detects rotation rates in multiple spatial directions, and provides the optical path for interference measurement. This multi-functionality enables precise rotation measurement in a compact form factor suitable for chip-integration.
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
Enables precise, cost-effective, and compact measurement of rotation rates in all three spatial directions with high sensitivity and accuracy, utilizing a small installation space and shared optical components.
Implementation Method 1
a beam splitter, which is configured and disposed to split a light beam received from a light source and to guide a thus obtained first partial light beam into the first end of the waveguide and to guide a second partial light beam into the second end of the waveguide
Implementation Method 2
In a chip-integrated embodiment, the light is continuously transmitted in two opposite directions into a wound optical waveguide. Due to the Sagnac effect, the effectively traveled length of the two light paths varies as the system rotates.
Implementation Method 3
the detector unit, which is configured to detect and evaluate the light from the first end of the waveguide with the light from the second end of the waveguide
Implementation Method 4
It is also possible to measure a rotation rate using optomechanical coupling. Due to the influence of a moving Coriolis mass on the refractive index of a light guide or an optical resonator, phase shifts can be used as a measurement signal
Implementation Method 5
phase shifts can be used as a measurement signal by Mach-Zehnder interferometers (MZI)
Data Source
AI summary
A sensor unit. The sensor unit includes a waveguide including a first end and a second end opposite to the first end. The sensor unit includes a beam splitter, which is configured and disposed to split a light beam received from a light source and to guide a thus obtained first partial light beam into the first end of the waveguide and to guide a second partial light beam into the second end of the waveguide. The beam splitter is further configured and disposed to direct light from the first end of the waveguide to a detector unit and to direct light from the second end of the waveguide to the detector unit. The sensor unit includes the detector unit, which is configured to detect and evaluate the light from the first end of the waveguide with the light from the second end of the waveguide.