Atomic Inertial Sensor Closed-Loop Feedback for Phase Readout Stability
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Solution Overview
Problem
Existing inertial sensors face challenges in maximizing sensitivity due to variations in phase differences induced by inertial forces, particularly in maintaining operation near null points, where small phase changes result in large derivative signal changes, necessitating improved feedback mechanisms.
Innovation Solution
A closed-loop feedback system is implemented using atomic inertial sensors coupled with MEMS inertial sensors, where phase shifting and optical frequency tuning are employed to maintain the null signal, and direct inputs from MEMS sensors are used to null the phase readout, enabling precise control and enhanced sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the atomic inertial sensor operates in open loop mode, then the device complexity is reduced, but the measurement precision deteriorates due to inability to maintain operation near null points
Solution Approach 1:
The patent implements a closed-loop feedback system where the atomic inertial sensor output is continuously compared to a setpoint (null point), and the error signal is fed back to adjust the sensor operation. This feedback mechanism maintains the sensor operating point near the null point where sensitivity is maximized, resolving the contradiction between measurement precision and device complexity by introducing controlled feedback.
Solution Approach 2:
The patent dynamically adjusts operating parameters (such as phase shifts or frequency offsets) based on the error signal to maintain optimal operating conditions. By changing parameters in real-time according to the feedback loop, the system preserves high sensitivity without requiring overly complex mechanical or structural modifications.
2Measurement precision
If closed loop feedback is implemented to maintain operation near null point, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary processing stage that computes the error signal between the sensor output and the setpoint, then applies appropriate compensation or adjustment. This intermediary layer manages the complexity by breaking down the feedback control into discrete, manageable computational steps rather than requiring complex hardware modifications.
3Measurement precision
If phase shifting and optical frequency tuning are employed to stabilize null signal, then measurement precision is enhanced, but ease of operation deteriorates due to complex control requirements
Solution Approach 1:
The patent replaces mechanical or manual adjustment mechanisms with optical frequency tuning and phase shifting controlled through electronic feedback loops. This substitution allows for more precise and stable control of the null signal while reducing the need for manual intervention, thereby improving measurement precision and eventually simplifying operation through automation.
Solution Approach 2:
The closed-loop feedback system automatically adjusts phase and frequency parameters to maintain the null point without requiring continuous manual calibration. The system serves itself by detecting deviations and applying corrective adjustments autonomously, improving both precision and ease of operation over time.
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 closed-loop feedback system significantly enhances the sensitivity of atomic inertial sensors by stabilizing the phase readout, allowing for accurate measurements of delta rotation and delta velocity, and integrates MEMS sensors to correct biases and scale factors, resulting in improved navigation accuracy.
Implementation Method 1
A class of inertial sensors based on atom interferometry use pulses of light to split, and later, recombine the quantum wavefunctions or wavefunction from a sample of cold thermal or quantum degenerate atoms (Bose-Einstein condensate). While split, the phases of the separate parts evolve independently, allowing the accumulation of a phase difference due to the presence of acceleration and/or rotation.
Implementation Method 2
A closed-loop feedback system is implemented using atomic inertial sensors coupled with MEMS inertial sensors, where phase shifting and optical frequency tuning are employed to maintain the null signal
Implementation Method 3
direct inputs from MEMS sensors are used to null the phase readout, enabling precise control and enhanced sensitivity
Data Source
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AI summary
An apparatus for inertial sensing is provided. The apparatus comprises at least one atomic inertial sensor, and one or more micro-electrical-mechanical systems (MEMS) inertial sensors operatively coupled to the atomic inertial sensor. The atomic inertial sensor and the MEMS inertial sensors operatively communicate with each other in a closed feedback loop.