The Structural Research Of Micromichined Gyroscope Based On Nonresonace Principle

Micro-machined gyroscopes have a variety of applications 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. In the dissertation, a new micro-machined vibratory gyroscope, based on non-resonance principle, is investigated, including the operating principle, design and fabrication, packaging and measurement of the device.The details are as following:1) It describes the basic operating principle of the traditional micro-machined gyroscope, and analyses the damping of gyroscopes, at last it points out the shortage of the conventional micro-machined gyroscope:①frequency fluctuation.10% error in frequency makes the sensitivity reduce to 5.3%,so we must try to make the frequency of driving and sensing match.②quality factor. higher the quality factor, higher the sensitivity is. But when there is a error between driving and sensing frequency, higher the quality factor , lower the sensitivity is. So we must find the optimal quality factor.③model　coupling. the conventional gyroscope drives and senses with a mass, so there is model coupling between driving and sensing model.2) A new micro-machined gyroscope is designed and present. The models of the gyroscope dynamical system are presented and dynamic equations of the gyroscope are derived. It compares the parameter sensitivity analysis with conventional gyroscope on fabrication variation, pressure variation , temperature variation. The paper also discusses the error of the gyroscope, which can be sorted into principle error and non-principle error, and then designs the whole gyroscope. Based on the finite element theory, the drive and sense frequencies formula and the sensitivity formula are derived and the simulation result is given.3) It describes the Bulk Silicon Dissolved Wafer Process and the Deep Dry Silicon on Glass process, and compares the advantages and disadvantages between them, then analyses the performance of gyroscope based on different process in residual stress and quality factor. At last, it compares the experimental results, the result indicates that the sensitivity of the gyroscope processed on DDSOG is about ten times greater than before.4) The prototype device is measured and the gyroscope drive and sense performance is tested with its circuits. The result shows: the gyroscopes'driving frequency and quality factor are 2105Hz and 94,scale factor is 14.8mV/°/s , bias stability is 0.35°/s. The testing result is different from the emulational result, because of fabrication error. So we must adjust the dimension of the structure to reduce fabrication error.