梳状音叉双线振动硅微机械陀螺仪的技术研究

【作者】 管继平；

【导师】 刘晓明；

【作者基本信息】 电子科技大学 ， 机械电子工程， 2010， 硕士

【摘要】 目前广泛运用于惯性导航技术领域的传统机械式陀螺仪和光学式陀螺仪,虽然它们的精度高而且制造及运用技术成熟,但都有着体积大和重量大的缺点,极大地限制了它们在微型化场合的运用,与当前微型化发展潮流相悖。随着20世纪八九十年代MEMS技术的发展,一种利用MEMS加工技术开发的微机械陀螺仪得到了迅猛发展。微机械陀螺仪具有微型化、集成化、动态性能好、能耗低、易于数字化和智能化、可靠性高、寿命长等诸多优点,解决了传统机械式陀螺仪和光学式陀螺仪无法在微型化场合应用的难题,对惯性导航技术有极大的需求的商业和军事应用领域有着举足轻重的意义和价值。微机械陀螺仪的精度参数通常由漂移率和分辨率进行标定。虽然微机械陀螺仪微机械陀螺仪相对传统机械式陀螺仪和光学式陀螺仪有诸多优点,但目前国内外的研究机构开发出的绝大部分微机械陀螺仪漂移率和分辨率精度性能只达到了速率级别应用要求,限制了它们在需要高精度的惯性级别应用场合的使用。因此,提高微机械陀螺仪漂移率和分辨率性能成了国内外研发机构开发微机械陀螺仪的首要目标。为了解决微机械陀螺仪仪漂移率和分辨率精度性能低下的问题,本文在总结前人成果的基础上,特别是在美国佐治亚理工学院开发的一款微机械陀螺仪的基础上,开发出了一种梳状音叉双线振动微机械陀螺仪结构。该梳状音叉双线振动微机械陀螺仪结构采用了对称型双折叠梁作为弹性支撑梁,对结构的驱动模态和检测模态起到了解耦作用;同时,该结构对驱动梳齿采用了独特的隔离设计,能够极大的降低驱动信号对检测信号的正交干扰。通过解耦和隔离设计,可以极大的降低微机械陀螺仪正交误差,从而提高陀螺仪的漂移率精度。通过对弹性支撑梁的各个几何参数进行优化设计,该微机械陀螺仪具有高品质因素的良好特性,从而为提高陀螺仪的分辨率打下了基础。本文通过有限元分析软件ANSYS对梳状音叉双线振动微机械陀螺仪结构的设计方案的优越性进行了分析验证。通过解耦有限元分析,验证采用折叠梁设计使系统驱动模态和检测模态间的耦合作用降到了1.9%以下;通过隔离有限元分析,验证经过隔离设计以后,驱动信号对检测信号的正交干扰降到了未经隔离作用的2.5%以下。通过理论分析,并通过Matlab仿真,得到梳状音叉双线振动硅微陀螺仪品质因素可达51×105,该梳状音叉双线振动微机械陀螺仪有非常高的分辨率。本文设计的微机械陀螺仪性能优越,结构新颖,已经申请了国家专利。更多还原

【Abstract】 The traditional mechanical gyroscopes and optical gyroscopes are broadly applied to the initial navigation field currently. Though they are characterized by high precision and maturity in manufacturing and application, they are flawed by their bulk volumes and heaviness, which limit their usage in micro-scale application and are contradict to current microminiature development trends. Micromachined gyroscope is characterized by miniaturization, integration, good dynamic performance, low energy consumption, easy to be digitalized, high reliability, long lifecycle as well as other advantages, whose characters surpass the limitation for traditional mechanical gyroscopes and optical gyroscopes to be used in micro-scale application, which holds valuable contribution to the those commercial and military industries which holds large demands of initial navigation technology.The precision of micromachined gyroscopes are calibrated by bias drift and resolution, respectively. Though they possess various advantages compared to their bulk counterparts, most micromachined gyroscopes developed by domestic and foreign research agents have low bias drift and resolution performance which merely reaches rate level application and limited to precise applications as initial level ones. Thus, it is the primary objective to improve bias drift and resolution performance of micromachined gyroscopes for micromachined gyroscopes research agents. This thesis is focused on a comb-driven-tuning-fork-two-lane-vibrating-silicon micromachined gyroscope structure aimed to improve bias draft and resolution performance based on the works of forerunner, especially base on the efforts of Georgia Institute of Technology of America.The symmetry dual folds spring suspension employed in this structure decoupled the mechanical coupling effects between the drive mode and the sense mode; the special isolation mechanism designed within the structure could largely decrease the cross talk to the sense signal by drive signal. The quadrate error of micromachined gyroscope can be lowered through decoupling and isolation design, which brings in improvement of bias drift performance. Through optimal design of the geometric parameter of the spring suspension, this structure is characterized by high quality factor, by which the foundation for the resolution improvement of was laid.Base on ANSYS finite element simulation software, this thesis verified the superiority of the design solution of this micromachined gyroscope. Through the decoupling analysis, the decoupling effect between drive mode and sense mode of the system decreased to below1.9% by employing folded beam design; through the isolation analysis, by the special layout design of drive combs and the folded beam, the orthogonal errors in the detection direction induced from the bias force of the driving force is lower to 2.5% of the one with no decoupling mechanism. Through theoretical analysis and Matlab simulation, it demonstrates that this micromachined gyroscope reached a quality factor of 51×105, which would bring in rather precise resolution.This micromachined gyroscope is characterized by predominant performance and novel structure design and its design was submitted to national patent agency for patent application.更多还原