Vibratory Gyro Phase Sync Circuit for Bias-Free Startup
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Solution Overview
Problem
Existing vibratory angular velocity sensors with phase synchronization circuits using operational amplifiers and capacitors are prone to activation failures due to biases between inputs, leading to shifted drive signal frequencies and improper vibrator activation.
Innovation Solution
Incorporating a short-circuit switch to bypass the capacitor in the integrator at activation, forming a voltage follower circuit to prevent integration of biases, and switching to feedback control after a predetermined time to ensure normal vibrator operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an integrator using an operational amplifier and capacitor is used in the phase synchronization circuit, then frequency control capability is improved, but activation reliability deteriorates due to bias integration
Solution Approach 1:
The short-circuit switch is activated before the main activation to pre-clear any bias in the integrator by shorting the capacitor. This preliminary action prevents bias integration from occurring during subsequent operation, thereby maintaining both frequency control capability and activation reliability.
Solution Approach 2:
The capacitor is temporarily extracted from the integrator circuit during activation by using the short-circuit switch to bypass it. This extraction prevents the capacitor from integrating bias signals during critical activation phases, while allowing the integrator to function normally with the capacitor during steady-state operation.
2Productivity
If the capacitor in the integrator is used during activation, then frequency signal generation is improved, but bias integration occurs causing drive signal frequency shift
Solution Approach 1:
The circuit configuration dynamically changes during activation: the short-circuit switch initially shorts the capacitor to prevent bias integration, then opens to allow the capacitor to function for frequency signal generation. This dynamic switching ensures both accurate frequency generation and prevention of frequency shifts.
Solution Approach 2:
The short-circuit switch operates periodically during activation cycles, shorting the capacitor at specific intervals to clear accumulated bias. This periodic action maintains drive signal frequency accuracy while allowing continuous frequency signal generation from the integrator.
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
Prevents abnormal activation of the vibrator by reducing input biases, allowing for stable frequency control and normal operation of the sensor.
Implementation Method 1
the operational amplifier does not form an integrating circuit. Thus, the possibility that the bias between the two inputs to the operational amplifier is integrated can be reduced or prevented
Implementation Method 2
an integrator using an operational amplifier and a capacitor. In such a case, when there is a bias such as an error between two inputs to the operational amplifier
Implementation Method 3
the frequency of the primary vibration excited in the vibrating structure is adjusted by using the phase synchronization circuit
Implementation Method 4
when a primary vibration along a first axis along a plane is excited and the vibrating structure is rotated
Implementation Method 5
a secondary vibration along a second axis tilted from the first axis is excited in the vibrating structure due to a Coriolis force
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A vibratory angular velocity sensor (100) includes a phase synchronization circuit (26) to output a frequency signal to control a frequency of a drive signal input to a vibrator (10). The phase synchronization circuit (26) includes a comparator (41) to compare a detection signal from the vibrator (10) with a reference signal generated based on the frequency signal, an integrator (42) including an operational amplifier (50) and a capacitor (70) to output an integrator output signal based on an output from the comparator (41), an oscillator (43) to output the frequency signal having a predetermined frequency based on the integrator output signal from the integrator (42), and a short-circuit switch (44) to cause short circuit so as to bypass the capacitor (70) of the integrator (42) at a time of activating the vibrator (10).