System Modeling And Core Circuit Module Design Of Disk Resonator Gyroscope

MEMS(Micro-Electro-Mechanical system)gyroscope is a kind of sensor based on Coriolis force effect,which is used to detect the angular velocity of object rotation.It is a key component in the fields of aerospace,submarine and attitude measurement.With the increasing demand of emerging high-end applications for high-performance MEMS disk resonator gyroscope,the performance requirements of gyroscope mechanical structure are improved,and the development of interface control circuits such as digital interface and self-calibration is promoted.Through the system modeling and simulation analysis of the disk resonator gyroscope,the core module of its interface circuit is designed,which is of great significance to the research of high-performance MEMS gyroscope.Firstly,the working principle of MEMS disk resonator gyroscope is analyzed,and the mechanical structure model and bandpass SDM(Sigma-Delta Modulator)model of the gyroscope are established.After that,the closed-loop drive circuit and closed-loop detection circuit are established based on the mechanical structure model,and the system model of the disk resonator gyroscope is built and simulated to verify the function of the gyroscope and the performance of the interface circuit.The driving circuit controls the harmonic oscillator to do simple harmonic vibration,and the detection circuit detects the gyro input angular velocity signal and controls the force rebalancing.The core module of the detection loop is the bandpass SDM,which converts the analog signal into the bit stream feedback signal,and uses the oversampling and noise shaping technology to improve the overall performance of the system.Then,the non-ideal factors of the disk resonator gyroscope system are analyzed theoretically,including the nonlinearity and noise of the mechanical structure,the noise of the SDM in the detection loop.The fourth-order single loop negative feedback bandpass SDM non-ideal system model and the non-ideal closed-loop detection model of the gyroscope are established,and the whole non-ideal system of the disk resonator gyroscope is simulated and analyzed.The sub module resonator,quantizer,DAC and the whole circuit design simulation and layout design simulation of the bandpass Sigma-Delta modulator are completed by using 0.35 um BCD process.The overall simulation environment is as follows: the power supply voltage is 5V,the input signal frequency is 5k Hz,the sampling frequency is 20 k Hz,the results of post simulation test are as follows: the signal-to-noise ratio of SDM is 92.06 d B(bandwidth 40Hz),and the significant digits is 15 bits,which meets the requirements of this subject.