Research On Micro-machined Gyroscope Dynamic Characteristics

Micro-machined gyroscopes have a variety of application in many fields due to their small size, light weight and low cost. Many efforts have been spent in improving the sensitivity in past years. Although there have been test result on micro-gyroscope dynamic characteristics, quantitative results relating the dynamic properties to micro-gyro design are not yet available. In this dissertation, the dynamic characteristics of the micro-machined gyroscope are analyzed, and finite element analysis software is used to simulate the micro-machined gyroscope. The effect of primary structure dimensions on nature frequency of micro-machined gyroscope is studied by finite element analysis software-ANSYS. According to matching of driving mode frequency and detection mode frequency, the structure dimensions are optimized.The main content in this dissertation is as fellow: (1) Based on Lagrange equation, the dynamic equation of micro-machined gyroscope is established, then the stiff coefficient and damp coefficient are analyzed. (2) The effect of the electrostatic force in micro-machined gyroscope: The formulae on calculation the driving force is given, then the effect of the electrostatic negative stiff and negative damp are analyzed, and the pull-in phenomenon are analyzed. (3) Based on the dynamic equation of the micro-machined gyroscope, the dynamic characteristics are analyzed, and formulae on calculation the sensitivity and non-linearity are given. In the case of considering the input angular acceleration, the bandwidth characteristics are analyzed and simulated. (4) Analysis of the errors and the noise in micro-machined gyroscope: Based on the dynamic equation of the micro-machined gyroscope, the characteristic of the errors and the noise in micro-machined gyroscope are analyzed, and the effects of the residual stress on the performance of micro-machined gyroscope. (5) The simulation of micro-machined gyroscope by finite element method (FEM): The effect of primary structure dimensions on nature frequency of micro-machined gyroscope is studied by finite element analysis software-ANSYS. According to matching of driving mode frequency and detection mode frequency, the structure dimensions are optimized.By means of the theoretical analysis of the dynamic characteristic of micro-machined vibratory rate gyroscope, we get following conclusion: Micro-machined vibratory rate gyroscope will have high sensitivity and wide bandwidth at the same time when the driving frequency equals to the driving mode frequency, and the nature frequency of the driving mode and sensing mode have a departure, meanwhile the damping of driving mode and sensing mode are as far as possible identical and little.The electrostatic analysis of Micro-machined vibratory rate gyroscope shows that the drives of the sensing mass may use the in-plane electrostatic force.The effect of primary structure dimensions on nature frequency of micro-machined gyroscope is studied by finite element analysis software-ANSYS. According to matching of driving mode frequency and detection mode frequency, the structure dimensions are optimized, which provides help for improving the structure and fabrication process.The formulae on calculation the sensitivity and non-linearity are given. In the case of considering the input angular acceleration, the bandwidth characteristics are analyzed and simulated.