Research On Digital Measurement And Control Circuit Of Multi-ring Resonant Micromachined Gyroscope

Multi-ring resonance micromachined gyroscopes are widely used in the aerospace field due to their small size,high accuracy,and strong impact resistance.However,affected by various factors such as air damping and temperature change,the working state of the gyroscope needs to be maintained by corresponding measurement and control circuits.In this paper,the working principle of Coriolis gyroscope is firstly studied,and the vibration equation of the gyroscope is calculated by using the ring resonator model.Combined with the actual physical structure of the multi-ring gyroscope,the method of gyroscope drive and signal detection in force balance mode and the implementation method of orthogonal control loop are obtained.COMSOL software was used to simulate the multi-ring gyroscope,and the key parameters such as the resonance frequency and Q value of the gyroscope were obtained.Based on this,the design of the gyroscope digital measurement and control circuit was performed.In the gyro digital measurement and control circuit,the frequency tracking circuit is a key component.The gyro monitoring signal is tracked to complete the real-time monitoring of the gyro vibration state.At the same time,an orthogonal reference signal is generated according to the monitoring signal to demodulate and drive the gyro signal.Because the resonance frequency of multi-ring gyroscope heads with different structures is too large,the traditional frequency tracking circuit can only perform frequency tracking on a single gyroscope head in order to ensure high accuracy requirements.Gyroscopes with large resonance frequency differences cannot be shared.Increased designer workload.In order to solve this problem,based on a high-speed ADC and using the CORDIC algorithm as a signal generation module,this paper proposes a frequency tracking circuit suitable for multi-ring meter heads with different resonance frequencies,and uses this as the core to complete the entire design of digital measurement and control circuit.This article selects the Spartan-6 series FPGA as the digital circuit implementation platform,divides the measurement and control circuit into functional modules,completes the code writing and simulation of each module,ensures the correctness of the code,and finally obtains the engineering file of the entire digital measurement and control circuit.Download to FPGA for board-level testing.Finally,design experiments are performed to test the related performance of the frequency tracking circuit,and compared with traditional implementation methods,the experimental results are analyzed.After testing,when using a 12-bit ADC to track the frequency of the input signal from 5k Hz to 50 k Hz,the frequency difference can be guaranteed to be less than 0.002%,and the capture time is less than 2ms.Under the premise of ensuring the performance of the circuit,the frequency tracking circuit increases the application range of the multi-loop resonant micro-mechanical gyroscope digital measurement and control circuit.