Vibrating Gyro BTL Circuit AGC Drive Voltage Control
Solution Overview
Problem
Existing vibration gyros face challenges in achieving high-sensitivity gyro characteristics when the input power supply voltage is reduced, leading to decreased mechanical vibration amplitude and sensitivity, due to limitations in drive voltage amplitude and oscillation frequency matching with the resonance point of the piezoelectric vibrator.
Innovation Solution
A vibration gyro configuration that includes a piezoelectric vibration unit, an automatic gain control circuit, and a balanced transformerless (BTL) circuit, where the BTL circuit amplifies the detection voltage phase-inverted output to increase the mechanical vibration amplitude and sensitivity, while maintaining the drive voltage within the dynamic range of the automatic gain control circuit, even with reduced power supply voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the drive voltage amplitude is increased to increase mechanical vibration amplitude and sensitivity, then the sensitivity of the vibration gyro is improved, but the drive voltage may exceed the dynamic range of the automatic gain control circuit causing oscillation stops
Solution Approach 1:
The patent implements automatic gain control (AGC) that uses feedback to dynamically adjust the drive voltage amplitude. The AGC circuit monitors the output signal and automatically adjusts the gain to keep the drive voltage within the dynamic range, preventing oscillation stops while maintaining high sensitivity operation
Solution Approach 2:
The patent makes the drive voltage amplitude dynamic rather than fixed. The automatic gain control circuit continuously adjusts the drive voltage based on operating conditions, allowing the system to adapt between low-voltage and high-voltage operation modes to optimize both sensitivity and stability
2Use of energy by moving object
If the power supply voltage is reduced to lower power consumption, then energy efficiency is improved, but the mechanical vibration amplitude and sensitivity decrease
Solution Approach 1:
The patent changes the operational parameters of the vibration gyro by implementing automatic gain control that adjusts the drive voltage amplitude and oscillation frequency. This allows the system to maintain high sensitivity by optimizing the drive parameters dynamically, even when the overall power supply voltage is reduced for lower power consumption
3Measurement precision
If the oscillation frequency is matched to the resonance point of the piezoelectric vibrator to maximize vibration amplitude, then the mechanical drive amplitude is improved, but the circuit complexity increases due to automatic gain control and phase-shift circuits
Solution Approach 1:
The patent implements automatic gain control and phase-shift functions within the existing oscillation circuit architecture. The AGC circuit serves multiple purposes: it controls the drive voltage amplitude, maintains oscillation stability, and enables resonance frequency matching, thereby achieving enhanced mechanical drive amplitude without proportionally increasing circuit complexity
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
This configuration enhances the mechanical vibration amplitude and sensitivity of the vibration gyro, allowing for high-sensitivity gyro characteristics to be maintained even with reduced power supply voltage, preventing oscillation stops and maintaining the drive voltage within safe operational ranges.
Implementation Method 1
generates detection voltages, between which a potential difference corresponding to the deformation is produced, at the first and substrate detection electrodes
Implementation Method 2
when deformed by a Coriolis force
Data Source
AI summary
A piezoelectric vibrator of a vibration gyro vibrates in response to a drive voltage Vdrv input into a drive electrode, and when deformed by a Coriolis force, generates detection voltages Vagc, between which a potential difference corresponds to the deformation, at detection electrodes. An AGC circuit outputs a drive voltage Vdrv while performing automatic gain control so that the detection voltages Vagc have a given amplitude. A phase inversion circuit and a BTL amplifier circuit output a BTL voltage Vbtl, whose phase is opposite to the detection voltage Vagc and whose amplitude has been increased, to the detection electrodes via detection resistances. The AGC circuit reduces the detection voltages Vagc in order to prevent the drive voltage Vdrv from exceeding a design upper limit value V′drv.