| High-performance microelectromechanical(MEMS)gyroscope is one of the core technologies to win the future informatization and intelligent warfare.At present,foreign countries are implementing strict technical control over China in this field.In order to break through foreign technical blockades and protect the strategic security of our country,we must master the core technology of high-performance MEMS gyroscopes and realize independent development of high-performance MEMS gyroscopes.In this study,with the goal of developing high-performance MEMS gyroscopes,a new type of MEMS gyroscope named honeycomb MEMS gyroscope is proposed.Key technologies such as resonant structure optimization,frequency split suppression and scale factor error suppression are studied.Eventually,a high performance honeycomb MEMS gyroscope prototype has been successfully developed.Contributions are summarized as follows.1.A novel honeycomb MEMS gyroscope is proposed.The dynamic model,key performance model and simulation model of the gyroscope are established.Inspired by the excellent mechanical properties of the honeycomb structure in nature,a novel honeycomb MEMS gyroscope is proposed.The gyroscope holds plenty of advantages including symmetry working modes,large capacitance area and good fabrication error robustness.Based on the method of lumped parameter equivalence,the dynamic model,key performance model and simulation analysis model of honeycomb MEMS gyroscope are established.According to the theoretical model,the key technologies to develop high performance honeycomb MEMS gyroscope are proposed.2.The comprehensive optimizations of resonant structure of honeycomb MEMS gyroscope are completed.Based on the finite element method,relationships between the structure parameters and the key performances are studied,and structure parameters such as the ring width and diameter of the outer ring are optimized.Based on the stiffness-mass decoupling principle,the influence of adding lumped-masses on the resonant structure is analyzed systematically.And a stiffness-mass decoupled honeycomb MEMS gyroscope is designed and fabricated.Test results show that the quality factor of the honeycomb MEMS gyroscope is increased from 80 k to 650 k,and the decaying time constant is increased from 1.5s to 50.4s after the structure optimizations,achiecing the goal of improving the quality factor and decaying time constant of the gyroscope through structure optimization.3.Frequency split suppression is achieved based on the orthogonal loop disturbance method.Frequency split is extracted based on the orthogonal loop disturbance method,and the frequency split suppression is realized through closed-loop control.The technology is investigated in the following three steps: theoretical analyses,simulation verification and experimental verification.Test results verify the effectiveness of the technology and the goal of improving the signal-to-noise ratio and zero offset stability of the gyroscope is achieved.4.Scale factor error suppression is achieved based on the in-phase loop disturbance method.Scale factor error is extracted based on the in-phase loop disturbance method,and the scale factor error suppression is realized through closed-loop control.The technology is investigated in the following three steps,namely,theoretical analyses,simulation verification and experimental verification.Test results verify the effectiveness of the technology,and the goals of reducing the temperature coefficient and improving the temperature stability of scale factor are achieved.5.A high-performance prototype of honeycomb MEMS gyroscope is developed.Based on the above-mentioned theories and technologies,this study designed and fabricated a high-performance prototype of honeycomb MEMS gyroscope,and conducted comprehensive tests on the prototype.Test results show that the bias instability of the prototype under room temperature reaches 0.019°/h,and the angle random walk reaches 0.00674°/√h,achieveing the goal of the thesis. |
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