Gyroscopic Sensor Bias Control for Scale-Factor Error Reduction
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Solution Overview
Problem
Existing gyroscopic measurement methods suffer from measurement errors due to defects in the vibrating element, excitation control electronics, and electronic detection systems, leading to inaccuracies in angular speed measurements, particularly the scale factor error, which are not effectively mitigated by existing correction methods.
Innovation Solution
A gyroscopic measurement method that introduces a predetermined bias into the measurement of the angular position of the pilot mode, causing a controlled rotation of the direction of the pilot and detection modes, allowing for the cancellation of harmonic errors and improving measurement precision by servoing the vibration amplitudes with biased forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional gyroscopic measurement methods are used, then the sensor can operate with standard measurement procedures, but measurement errors due to defects in the vibrating element, excitation control electronics, and electronic detection systems lead to inaccuracies in angular speed measurements
Solution Approach 1:
The patent applies periodic action by modulating the excitation signal at a specific frequency (e.g., 100 Hz) to periodically vary the geometric vibration position of the gyroscope. This periodic modulation allows the system to measure harmonic errors at different phases and frequencies, enabling their identification and cancellation through signal processing, thereby improving measurement precision while maintaining reliable operation
Solution Approach 2:
The patent changes the operating parameters of the gyroscope by intentionally modulating the excitation frequency and amplitude to create controlled variations in the vibration geometry. By varying these parameters periodically and analyzing the resulting harmonic components, the system can separate and eliminate error signals from the measurement, thus improving both precision and reliability
2Manufacturing precision
If the geometric vibration position of the gyroscope is voluntarily modified by electrostatic means over time, then gyroscope calibration is improved, but the device complexity increases due to additional control electronics and signal processing requirements
Solution Approach 1:
The patent makes the existing excitation electronics serve a dual function: both maintaining the normal operation of the vibrating element and implementing the periodic modulation for error cancellation. By utilizing the same electrostatic actuation mechanisms for both purposes, the system achieves improved calibration precision without significantly increasing device complexity
Solution Approach 2:
The patent implements feedback by continuously monitoring the vibration signals and using signal processing to identify and cancel harmonic errors. The measured vibrations are processed to extract error components, which are then subtracted from the raw measurement to produce a corrected output, achieving high calibration precision through intelligent signal processing rather than complex hardware modifications
3Measurement precision
If a command signal is used to make the geometric vibration position rotate in alternating directions, then harmonic errors are minimized, but the average value of the error committed is not zero over one period due to instabilities in the conversion chain
Solution Approach 1:
The patent ensures continuous error cancellation by processing the vibration signals in real-time and continuously applying corrections to the measurement output. The signal processing operates continuously throughout the modulation cycle, maintaining measurement precision without interruption and compensating for instabilities in the conversion chain through ongoing feedback and correction
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 method enhances the precision of gyroscopic measurements by reducing measurement errors, particularly the scale factor error, through the use of biased forces that compensate for inherent sensor defects, resulting in more accurate angular speed determination.
Implementation Method 1
If the component according to the sensitivity axis of the instantaneous rotation velocity vector of the housing relative to an inertial reference frame is non-zero, the displacement of the vibrating element according to the direction of the pilot mode generates a Coriolis force. This Coriolis force excites the vibrating element according to the direction of the detection mode, perpendicular to the direction of the pilot mode, to an amplitude which is proportional to the component according to the sensitivity axis of the instantaneous rotation velocity vector.
Data Source
AI summary
The present invention relates to a gyroscopic measurement method by means of a sensor (10) comprising a housing (12) and a vibrating element (15) able to vibrate relative to the housing (12) simultaneously according to a direction (x) of a pilot mode and a direction (y) of a detection mode, comprising the control (110) of a first and a second vibration amplitude of the vibrating element (15) according to the directions of the pilot mode and detection mode respectively to a predetermined pilot amplitude (xmax) and detection amplitude (ymax), and the determination (120) of an instantaneous angular speed (Ωmes) of the housing (12).A predetermined bias (ξ(t)) is introduced into a measurement of an angular position (θ) of the direction (x) of the pilot mode used to determine a biased force (Fass,bias) to be exerted on the vibrating element (15) for the control of the first and/or second vibration amplitude, to cause controlled rotation of the direction (x) of the pilot mode in the plane of vibration (XY).