基于MEMS陀螺仪的微惯性测量系统的实现

微机电(MEMS)惯性传感器应用日益广泛,本文给出了一种基于新型MEMS陀螺仪的微惯性测量系统的实现.系统采用了ANALOG DIVICES公司的AIDS16255陀螺仪,其精度较高,并增加了校准功能,能够在内部对敏感度和偏差因子进行补偿.系统具有体积小、重量轻、可扩展性好等特点.本文给出了系统的原理图和软件流程的关键内容.     

一种MEMS陀螺仪的标定方法研究

微机电系统(MEMS)陀螺仪的测量误差是影响微惯性导航系统精度的重要因素.为了提高微惯性导航系统的精度,提出了一种利用三轴转台完成MEMS陀螺仪的标定方法.根据MEMS陀螺仪的误差模型,设计了标定试验方案和误差模型参数的辨识方法,并通过小波阈值去噪的方法对陀螺的输出数据进行去噪处理.试验与仿真对比分析结果表明:经误差补偿和去噪后MEMS陀螺仪的测量精度提高1～2个数量级,同时验证了该标定方法的正确性、有效性.     

Design of a packaging-friendly double-topology RF MEMS switch for space applications

Microsystem Technologies - This article presents the results of the research, design and a series of manufacturing steps of an RF-MEMS switch to be used in space communication systems. Design and...     

低成本MEMS陀螺实时滤波方法

为找到一种普遍适合低成本MEMS陀螺仪的随机误差实时处理方法,利用Allan方差分析法首先对MEMS陀螺仪进行分析,根据其误差特性进而设计了平均滤波算法以剔除粗大误差,然后使用最小二乘法,通过拟合前一段历史结果得到下一时刻输出的预测值,基于以上工作最终设计出Kalman滤波器对所输出进行滤波。由于将最小二乘法的推测作为预测过程,避免了系统状态模型难以准确建立的问题。该方法动态性能好,具有普适性。实验结果证明,该方法在静态和动态下均能有效工作,滤波后常值漂移被有效补偿,角度随机游走不再占误差的主要成分,均方差小于滤波前的十分之一。     

MEMS谐振陀螺实时自动模态匹配控制技术

为了消除温度对陀螺模态匹配的影响,提出了一种实现微机械谐振陀螺在温度-30～60℃内实时自动模态匹配控制方法。驱动模态和检测模态的谐振频率跟温度成线性关系,两轴的谐振频差与温度也成线性关系,该方法以驱动模态谐振频率作为温度参考而获得两模态谐振频差,根据谐振频差实时调节静电调谐电压,使得检测模态谐振频率与驱动模态谐振频率匹配。实验结果表明:检测谐振频率和驱动谐振频率在温度-30～60℃范围内,匹配误差不超过0. 3 Hz,验证了该方法的可行性、匹配精度,同时证明本文所采用的开环控制方案的有效性。     

MEMS陀螺误差辨识与补偿

由于制造工艺等原因,MEMS陀螺的随机漂移非常大,严重影响了系统的性能.通过自制的基于MEMS的捷联惯导系统的相关实验,对MEMS陀螺的确定性误差和随机误差分别进行了辨识和补偿.完成确定性误差补偿,对MEMS陀螺随机误差进行了时间序列分析,并建立了AR模型,根据所选模型参数建立了随机误差的系统方程,采用经典卡尔曼滤波进行随机误差补偿.实验结果说明:无论是静态下还是动态下,补偿后信号的方差都大大下降,说明了滤波效果较为明显,具有一定的工程应用价值.     

Matching mechanical response for a MEMS vibratory tuning fork gyroscope

Microsystem Technologies - This paper introduces the configuration of the MEMS tuning fork gyroscope with the connecting diamond-shaped frame to achieve the anti-phase mode in the driving...     

一种Z轴微机械陀螺的自解耦方法研究

在分析了微机械陀螺机械耦合误差产生原因的基础上,提出了一种解耦梁方案,可以从结构上消除振动式微机械陀螺敏感模态对驱动模态的耦合影响;基于该解耦梁方案设计了一种新型的Z轴微机械陀螺结构.分析表明,该陀螺结构消除了敏感模态对驱动模态的耦合影响,实现了解耦设计的目的.     

Chattering-free sliding mode control-based disturbance observer for MEMS gyroscope system

Microsystem Technologies - This paper proposes a novel disturbance observer (DOB) based on the free-chattering sliding-mode control (SMC) to compensate the changing of the disturbance and uncertain...     

MEMS陀螺仪驱动谐振频率的温度补偿方法

微机电系统(MEMS)陀螺的模态谐振频率和品质因子具有较强的温度敏感性,使得MEMS陀螺的输出零偏随温度漂移。为了解决零偏随温度漂移问题,提出了一种基于MEMS微机械陀螺的驱动谐振频率做温度基准的零偏温度补偿方法。温度在-40～60℃范围内变化,经多次循环测量陀螺零偏,获得零偏与温度之间的变化关系,并在此基础上,对零偏进行建模分析。利用谐振频率与温度的线性关系,以驱动谐振频率为温度参考,对陀螺零偏进行实时温度补偿。实验结果表明:上电零偏稳定性由补偿前的143. 81°/h变为补偿后的26. 51°/h,降低了5. 42倍;温度在-40～60℃范围内变化,补偿前后的零偏稳定性分别为1368. 05°/h和62. 86°/h,降低了22倍。     

嵌套环式MEMS振动陀螺的静电修调算法

对于工作在n=2模态谐振结构,静电修调是一种消除频率裂解、实现模态匹配的常用方法.基于环形谐振子的刚度扰动模型,提出了一种直观而实用的修调算法.通过巧妙地近似,并将嵌套环结构的内置修调电极等效为两簇簇带负刚度的“径向弹簧”,从而将单环谐振结构的理论模型成功应用于多环嵌套结构.最后通过静电修调实验对该算法进行了验证,实现了带误差谐振子的模态匹配.实验结果表明:通过该算法频率裂解从15 Hz左右被修到0.03 Hz左右.     

High-aspect-ratio photolithography for MEMS applications

High-aspect-ratio photolithography using a commercially available positive photoresist and a conventional contact mask aligner with standard UV light source is described. A multiple coating process is developed to obtain a photoresist thickness up to 23 μm while maintaining a smooth photoresist surface. Intimate contact between the mask and wafer is found to be most critical for high-resolution photolithography. Vacuum contact is found to be well-suited for this purpose. Additionally, edge bead removal is found to be of significant importance for intimate contact between the mask and the substrate. Prebake, exposure, and development conditions are optimized for resolution and aspect ratio. Maximum prebake temperature still allowing the photoresist to be developed is found to be the optimal temperature for obtaining high resolution. Prebake time distribution is optimized for avoiding residual stress in the photoresist, as well as maintaining high resolution, when multiple coating is applied. Minimum linewidth and spacing of 3.5 μm and 2.5 μm, respectively, and a maximum aspect ratio of 7.7 have been achieved in a photoresist thickness of 23 μm. Postbake improves the chemical resistance to subsequent processes, for example, electroless nickel plating using the photoresist as a mold. However, postbake also causes pattern distortion, which can be severe at times. Therefore, optimal process and design conditions for minimizing the pattern distortion have been studied     

Sensitivity analysis of an in-plane MEMS vibratory gyroscope

Microsystem Technologies - This paper aims to put forward a detailed sensitivity analysis of an in-plane MEMS gyroscope with respect to various performance criteria that are very critical for use...     

A HARPSS polysilicon vibrating ring gyroscope

This paper presents the design, fabrication, and testing of an 80-μm-thick, 1.1 mm in diameter high aspect-ratio (20:1) polysilicon ring gyroscope (PRG). The vibrating ring gyroscope was fabricated through the high aspect-ratio combined poly and single-crystal silicon MEMS technology (HARPSS). This all-silicon single-wafer technology is capable of producing electrically isolated vertical electrodes as tall as the main body structure (50 to 100's (μm tall)) with various size air-gaps ranging from submicron to tens of microns. A detailed analysis has been performed to determine the overall sensitivity of the vibrating ring gyroscope and identify its scaling limits. An open-loop sensitivity of 200 μV/deg/s in a dynamic range of ±250 deg/s was measured under low vacuum level for a prototype device tested in hybrid format. The resolution for a PRG with a quality factor (Q) of 1200, drive amplitude of 0.15 μm, and sense node parasitic capacitances of 2 pF was measured to be less than 1 deg/s in 1 Hz bandwidth, limited by the noise from the circuitry. Elimination of the parasitic capacitances and improvement in the quality factor of the ring structure are expected to reduce the resolution to 0.01 deg/s/(Hz)^0.5     

基于参数激励法的MEMS陀螺电馈通抑制方法

针对微机电系统(MEMS)陀螺驱动电极和感应电极之间存在寄生电容,导致驱动信号的电馈通,限制了陀螺仪的灵敏度的问题,采用一种新型驱动方式—参数激励法,可以有效改变陀螺的刚度。仿真测试表明,通过调节激励信号的参数(频率、幅度和相位),可以以可控的方式显著地减少电馈通。     

An analog circuit model for drive mode of MEMS vibratory gyroscope

Microsystem Technologies - In this paper, an analog circuit model for the drive mode of a two-degree-of-freedom MEMS vibratory gyroscope is presented. This model is implemented on a printed circuit...     

基于数字调节方法的MEMS陀螺零位补偿技术研究

针对环境温度影响导致MEMS陀螺零位输出变化较大的问题,设计了一种基于数字调节方法的零位补偿电路并提出了一种陀螺零位漂移特性的测试方法.该补偿电路依据陀螺内部温度传感器输出,实时调节补偿电路输出,实现零位补偿.采用全温(-40℃～+60℃)测试方法,研究得到陀螺零位漂移模型,再经过研究零漂值与补偿电路值之间的对应关系,求解出温度与补偿电路之间的数学模型.实验表明,采用该方法使陀螺零位在全温范围内稳定精度提高了一个数量级,证明了提出方法的可行性和有效性.     

Study on frequency stability of a linear-vibration MEMS gyroscope

Thermal-dependent frequency stability of a linear-vibration gyroscope, based on elastic theory of thin plate, is studied. As an elastic structure, the resonant frequency of the gyroscope is determined by the secant coefficient of thermal expansion of the material in which the gyroscope is made. For decreasing the frequency variation under different temperatures, the gyroscope can be changed in its structure to eliminate the thermal stress caused by mismatch of materials the gyroscope made in. Two gyroscopes with straight-beam and folded-beam supporting respectively are designed and analyzed. When replacing straight-beam by folded-beam in the gyroscope, the frequency variation of the gyroscope decreases. The two structures then are manufactured for testing. The testing shows the same result as analysis.     

MEMS陀螺随机误差模型研究

对MEMS陀螺随机误差进行了实验测试及研究,选取状态方程模型,基于近年来发展起来的随机系统子空间辨识方法,对MEMS陀螺随机误差进行建模,结果与Allan方差方法分析的噪声特性相符合,经与ARMA等模型比较,在同等性能下,所建模型具有阶次低的优点,更加适合于实时在线优化估计器.所提方法可以不加修改直接应用于对多轴陀螺的处理.     

A MEMS piezoelectric solid disk gyroscope with improved sensitivity

Microsystem Technologies - This paper introduces a MEMS piezoelectric solid disk gyroscope. The gyroscope operates in an in-plane elliptic bulk acoustic wave mode with a frequency of...