Ring Laser Gyroscope Thermal Gradient Compensation
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Solution Overview
Problem
Ring laser gyroscopes face challenges in accurately compensating for temperature gradients across the gyroscope sensor block, which affect bias error output, as existing thermal compensation models primarily rely on average temperature and temperature rate of change.
Innovation Solution
Implementing a thermal gradient compensation model that uses additional temperature sensors to measure and calculate temperature gradients across the laser block sensor, allowing for the derivation of coefficients to correct bias errors through regression analysis, thereby producing bias-compensated angular rate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional thermal compensation models using average temperature are used, then the system complexity is low, but the measurement precision deteriorates due to unaccounted temperature gradients
Solution Approach 1:
The patent divides the thermal compensation approach by separating average temperature compensation from gradient compensation. Multiple temperature sensors are placed at different locations on the laser block to independently measure temperature distribution, allowing gradient calculation without requiring a completely new compensation architecture.
Solution Approach 2:
The patent implements local quality by placing temperature sensors at specific strategic locations on the laser block where temperature gradients are most significant. This targeted sensing approach captures local thermal variations that affect gyroscope performance while minimizing the number of sensors needed.
2Reliability
If temperature gradient measurements are implemented, then the reliability improves by compensating for gradient-induced bias errors, but the device complexity increases due to additional sensors and computation
Solution Approach 1:
The patent performs preliminary action by pre-calculating compensation coefficients through regression analysis during a calibration phase. The compensation model parameters are determined in advance based on characterized temperature gradient effects, so that during operation, only simple coefficient application is needed rather than complex real-time gradient analysis.
Solution Approach 2:
The patent implements feedback by continuously measuring temperature gradients and using this information to dynamically adjust the bias compensation. The measured gradients feed into the compensation model, which then corrects the angular rate output in real-time, creating a closed-loop system that adapts to changing thermal conditions.
3Measurement precision
If multiple temperature sensors are added to measure gradients, then the measurement precision improves, but the manufacturing precision requirements increase for sensor placement
Solution Approach 1:
The patent merges the temperature sensing function with the existing gyroscope assembly by integrating the temperature sensors directly into the laser block structure. This integration allows temperature measurements to be taken at optimal locations without requiring separate mounting operations, thereby reducing the cumulative precision requirements.
Solution Approach 2:
The patent makes the laser block structure multi-functional by having it serve both as the optical cavity housing and as the mounting substrate for temperature sensors. This universal use of the laser block eliminates the need for separate precision-machined sensor mounts, reducing manufacturing precision requirements.
Data Source
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AI summary
Systems and methods for thermal gradient compensation for ring laser gyroscopes are provided. In one embodiment, a method for producing bias compensated angular rate measurements from a ring laser gyroscope comprises: sampling an angle measurement output from a laser block sensor to obtain an angular rate measurement; obtaining an laser block temperature measurement (T block ) for the laser block sensor; obtaining a temperature gradient measurement (T diff ) for at least one gradient line across a portion of the laser block sensor; calculating a rate bias error by applying parameters produced from the temperature measurement (T block ) and the temperature gradient measurement (T diff ) to a thermal gradient compensation model, wherein the thermal gradient compensation model includes at least one coefficient corresponding to the temperature gradient measurement (T diff ); and calculating a difference between the angle rate measurement and the rate bias error to produce a bias compensated angular rate measurement.