【作者】 李新刚；

【导师】 袁建平；

【作者基本信息】 西北工业大学 ， 飞行器设计， 2004， 博士

【摘要】 微机电陀螺与传统的机电类陀螺和光电类陀螺相比,具有成本低、尺寸小、重量轻、可靠性高等优点。对微机电陀螺的研究与开发已经成为近十几年内的研究热点,并将继续推动导航技术向前发展。基于目前的工艺水平,微机电陀螺只能用于低端导航系统,提高其可用精度的方法之一是对其进行误差特性分析、建模和补偿。 本文主要研究了微机电陀螺的误差分析、建模和补偿,以及在飞行器导航中的应用。首先对微机电陀螺的性能指标进行了总结并分析了其理想动力学模型,随后详细论述并分析了振动结构、换能器和电子电路三个主要部分的工作原理、性能和误差特性。基于上述研究结论,建立了适用于微机电陀螺的误差模型,对误差补偿理论进行了研究。最后根据建立的微机电陀螺误差模型,开发了分布式组合导航仿真系统和低成本飞行器组合导航系统原理样机,并进行了仿真分析和跑车试验。 本文的具体研究内容如下: 1) 对微机电陀螺的性能指标进行了归纳和总结,将理想微机电陀螺等效为2自由度质量-弹簧-阻尼系统,在开环和闭环两种工作模式下对其动力学模型进行了分析,确定了用于描述微机电陀螺结构特征参数的典型取值范围。 2) 研究了静电驱动和电容性检测技术,对微机电陀螺中常采用的平板电容器结构、横向梳结构和纵向梳结构进行了工作机理分析和性能比较,对静电驱动器和电容性敏感器中存在的正交误差和偏差进行了定性分析。 3) 对驱动电路存在的误差进行了分析,其主要为因相位延迟导致的正交误差。对单位增益缓冲器、跨阻放大器和电荷积分放大器三种基本检测单元的工作原理和噪声特性进行了分析和比较,表明电荷积分放大器的性能最好。随后分析并比较了同步检测、开关电容检测、相关双采样和伪差分检测四种典型检测电路的性能,同步检测和相关双采样能够消除较多的误差,其误差主要为第1级放大器的热噪声,该热噪声与机械热噪声相比往往要高几个量级。 4) 研究了两种典型的微机电陀螺结构:线振动结构陀螺和旋转振动结构陀螺。根据各自的动力学特征推导了完整的动力学模型,在模型中引入的主要结构不理想因素—质心偏移和振动质量偏斜—可以等效为结构的刚度矩阵和阻尼矩阵不对称,并表示成矩阵的非对角项。随后对上述模型进行了合理简化,采用轨迹图法和平均化方法进行了动力学特性分析,研究了模态控制问题。最后归类并分析了与结构相关的各种主次误差因素。 5) 详细论述了微机电陀螺的确定性误差模型和随机误差模型,以及相应的模型建立方法,着重分析了随机误差建模方法中的时间序列分析和Allan方差技更多还原

【Abstract】 Comparing with conventional electro-mechanical gyroscope and electro-optical gyroscope, MEMS gyroscope has the advantages of low cost, small size, low weight and high reliability. In the past decades MEMS gyroscope has become the major subject of widely research and development and will continue to boost the evolution of navigation technologies. At present, basing on the process level, MEMS gyroscope is restricted in the field of low level navigation. One of the methods for increasing its available accuracy is error analysis, modeling and compensation.Error analysis, modeling and compensation of MEMS gyroscope and its application in navigation of flight vehicle are researched in this paper. Firstly, performance indices of MEMS gyroscope are summarized and its ideal dynamic model is analyzed. Secondly, the operation principle, performance and error characteristics of three main parts, vibratory structure, transducer and electrocircuit, of MEMS gyroscope are discussed thoroughly. Thirdly, basing on the above conclusions, error model of MEMS gyroscope is built and its compensation theory is discussed. Finally, basing on the above error model of MEMS gyroscope, a distributed integrated navigation simulation system and a prototype of low cost integrated navigation system for flight vehicle are designed, simulation and car test are carried out and the conclusions are given.The detailed contents in this paper are as followed:1) Performance indices of MEMS gyroscope are summarized. Ideal MEMS gyroscope can be taken as an equivalent two freedom mass-spring-damping system and its dynamic model is analyzed under two operation modes of open-loop and closed-loop. The typical bounds of characteristic parameters for describing MEMS gyroscope’s structure are determined.2) Electrostatic actuator and capacitive detect technologies are studied. The operation mechanism of the common capacitor structure, plate, transverse comb and lateral comb, are analyzed and compared. Finally, qualitative analysis is given according to the cross error and bias which exist in the electrostatic actuator and capacitive sensor.3) Errors that existed in driven circuit are studied, it is indicated that the dominating error factor is cross error caused by the delay of phase. Operation principle and noise characteristics of thee fundamental detect circuit elements, unit gain buffer, tran-resistant amplifier and charge integrated amplifier, are analyzed and compared. It is indicated that the performance of charge integrated amplifier is the best. Operation principle and performance of four typical detect circuit, synchronous detect, switched capacitive detect, correlated double sampling areanalyzed and compared. It is indicated that the synchronous detect and correlated double sampling can eliminate the most parts of error sources, the dominating error sources of them is thermal noise of first stage of amplifier. The thermal noise is often several orders higher than the mechanical thermal noise.4) Two typical types of MEMS gyroscope, linear vibratory structure gyroscope and rotational vibratory gyroscope, are studied. The integrated dynamic models of them are deduced by the correlated dynamic characteristic. Structure imperfects, offset of center of mass and deflection of vibratory mass, are added into the above models by the form of non-diagonal items in asymmetry stiffness matrix and asymmetry damping matrix. Dynamic characteristics and operation mode control is analyzed basing on the simplified models with the methods of trajectory plot and parameter averaging. Finally, the primary and secondary error factors correlated with structure is classified and analyzed.5) Determinable error model, stochastic error model and modeling method are analyzed in detailed. Especially, stochastic error modeling methods are discussed, including time serial analysis and Allan variance method. The common error model equation is deduced by analysis of its primary and secondary error factors. Finally, to a specific type of MEMS gyroscope, error modeling and analysis are provided by the method of time serial analysis and Allan variance analysis respectively according to the static test data.6) Error compensation theories used for gyroscope are analyzed and compared. Especially, particle filtering theory which is the research focus at the present time is discussed in detail. The correlative filtering algorithm and the mixture filtering algorithm which can reduce computing consumption are deduced. Finally, a new cascade filtering structure is presented which not only can reduce computing consumption but also increase filtering robustness and the correlative filtering algorithm is also deduced.7) Basing on the above error model of MEMS gyroscope, a distributed integrated navigation simulation system and a prototype of low cost integrated navigation system for flight vehicle are designed, simulation and car test are carried out and the conclusions are given.更多还原