Nonlinear FM Gyroscope With Temperature Feedback for Bias Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current frequency modulated (FM) gyroscopes suffer from drift due to temperature variations and packaging material aging, leading to bias instability, which limits their use in applications without global positioning satellite reception, such as underwater environments, and existing solutions like optical gyroscopes are complex and costly.
Innovation Solution
A nonlinear FM gyroscope with positive feedback circuits and temperature control components maintains constant amplitude and temperature, using a degenerate-mode mechanical resonator and heating elements to reduce bias instability, implemented with MEMS technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional FM gyroscopes are used without temperature control, then the device complexity is reduced, but bias instability increases due to temperature variations and aging
Solution Approach 1:
The patent implements a temperature control system with feedback mechanisms that continuously monitor and adjust the temperature of the MEMS resonator to maintain constant operating conditions. This feedback approach compensates for temperature variations and aging effects, achieving bias instability of less than 10°/hr without requiring complex optical systems.
Solution Approach 2:
The patent controls the operating temperature parameter of the MEMS resonator to remain constant despite external temperature variations. By maintaining a stable temperature parameter, the system prevents drift in the resonator's natural frequency and other temperature-sensitive parameters, thereby reducing bias instability.
2Reliability
If optical gyroscopes are used to address drift, then bias instability is reduced, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex optical gyroscopic systems with a simpler MEMS-based mechanical resonator system. By using a degenerate-mode MEMS resonator with temperature control, the invention achieves comparable or superior bias instability performance without the complexity and cost of optical components, making the system suitable for underwater and other GPS-denied environments.
Solution Approach 2:
The patent employs inexpensive MEMS resonators and temperature control components instead of costly optical gyroscopes. This approach uses affordable, easily manufacturable components that achieve the required performance level, making the system economically viable for widespread deployment in various platforms including underwater vehicles.
3Reliability
If temperature control components are added to maintain constant temperature, then bias instability is reduced, but device complexity increases
Solution Approach 1:
The patent integrates the temperature control components (heating elements, temperature sensors) directly with the MEMS resonator structure, merging the sensing and actuation functions into a compact unified system. This integration minimizes the overall device complexity while achieving effective temperature stabilization and reducing bias instability.
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 nonlinear FM gyroscope achieves bias instability of less than 10°/hr for periods up to 10,000 seconds, enabling stable operation in various platforms, including underwater environments, without the need for complex or costly solutions.
Implementation Method 1
Frequency modulated (FM) gyroscopes are microelectromechanical (MEMS) sensors that exploit an angular momentum conservation effect to sense rotation
Implementation Method 2
A nonlinear FM gyroscope with positive feedback circuits and temperature control components maintains constant amplitude and temperature, using a degenerate-mode mechanical resonator and heating elements to reduce bias instability
Implementation Method 3
The nonlinear FM gyroscopes herein include subsystems that provides amplitude and temperature control to correct for bias drift. A pair of positive feedback circuits are used maintain a constant amplitude.
Data Source
AI summary
A nonlinear frequency modulated gyroscope includes a degenerate-mode mechanical resonator, positive feedback circuits, a temperature control component, and a gyroscope controller. The degenerate-mode mechanical resonator with two or more modes are coupled via a Coriolis effect. The positive feedback circuits for each mode of the degenerate-mode mechanical resonator include an analog or digital automatic gain control that maintains oscillations of each mode at a constant amplitude. The temperature control component includes a sensor and heating elements. The gyroscope controller is an application-specific integrated circuit, a field programmable gate array, or microcontroller. The degenerate-mode mechanical resonator, the positive feedback circuits, and the temperature control component are subsystems of the nonlinear frequency modulated gyroscope.