| A square symmetrical tri-axis gyroscope structure was proposed to realize the monolithic integrated three-axis gyroscope. Firstly, the research background and significance of this subject is introduced, the idea of design and working principle of the gyroscope is explained, while the dynamic model with its dynamic equation and damping analysis was given. Then, the structure design is given with a portion of its performance parameters calculated on the basis theory. The structure is analyzed and simulated by using the simulation software, while the focal point of the work is the analysis of its elastic beams to illustrate the influence of the beams’ sizes on the performance. Meanwhile, the amplitude frequency characteristics analysis, static analysis and modal analysis was simulated.The simulation results shows that the quality factor under the atmospheric pressure of its drive mode and z-axis sensing mode respectively are 9826 and 9834, however its 348 to the x/y-axis sensing mode which can be greatly improved by using vacuum encapsulation and damping hole. The sensitively of the z-axis and x/y-axis respectively are 30.192 fF/(°/s) and 38.541 fF/(°/s), the maximum stress under the applied load of 100 G is 1.942 MPa, while the Natural frequencies of each mode are 57.345 KHz,57.382 KHz and 57.395 KHz, which means that the matching performance between modal is good. The simulations for this gyroscope structure demonstrate that the design meet the requirements for the tri-axis gyroscope.The interface circuit of the gyroscope is analyzed in this article, the frame structure of the drive-sense circuit is designed with the analysis of some of the key circuit. Finally the processing technology of the MEMS gyroscope is introduced, and a preparation process based on SOI technology is presented. |
