电容式微机械陀螺双环路闭环驱动电路研究

为了提高微机械陀螺系统的检测灵敏度,对微机械陀螺系统的驱动电路进行了研究.分析了微陀螺闭环驱动系统理论,基于此提出一种双环路闭环驱动方法,并且利用数学工具simulink建立系统模型,验证此方法的可行性,最后设计完成相应电路.此方法引入锁相环实现闭环驱动电路的稳频控制;采用自动增益控制器(AGC)实现恒幅控制.利用Hspice完成电路级仿真.结果表明,微机械陀螺双环路闭环驱动电路建立稳定振荡的时间为45 ms,稳定振荡频率为2.7553 KHz,频率偏差为0.1 z,频率抖动为0.056563 Hz.相对于传统的AGC闭环驱动电路,此闭环驱动电路建立稳定振荡时间缩短了30.77%,频率稳定性是传统AGC闭环驱动电路的32.72%.微机械陀螺环路闭环驱动电路提高驱动信号性能,对于微机械陀螺检测灵敏度的提高有着重要意义.     

微机械陀螺闭环驱动电路的新方法

闭环驱动方式是目前高性能微机械陀螺的主流驱动方式,大部分的闭环驱动电路采用了自动增益控制模块以稳定输出信号的幅度,但是,采用AGC模块会限制电路的线性工作范围,而且输出摆幅有限,因此制约了微机械陀螺系统的灵敏度和稳定性。基于以上不足,在建立微机械陀螺系统等效电路模型的基础上,提出一种新颖的解决方案,采用比较器代替AGC模块,实现对陀螺输出信号幅度的控制,这种方案不仅电路结构更为简单,而且增大了整体电路的线性工作范围,能够始终输出满量程的驱动信号。     

高Q值音叉式微陀螺静电自激驱动研究

为了提高检测精度,对研制的具有滑膜阻尼的音叉式微机械陀螺采用静电自激驱动方式,它能够使驱动振动自动稳定在驱动模态的固有频率上,并保持恒定的驱动振动速度幅度。分析了静电自激驱动电路工作原理,采用自动增益控制(AGC)设计制作了相应的检测电路,实现了Q值为325、谐振频率为2.04 kHz微陀螺的闭环恒幅自激振动。     

MEMS振动陀螺闭环自激驱动的理论分析及数值仿真

对采用AGC(automatic gain control)控制实现的陀螺闭环自激驱动系统进行了理论分析,利用平均技术和相平面法求解出了MEMS振动陀螺闭环自激驱动系统的起振条件以及幅度稳定条件的解析表达式,并进行了数值仿真验证。在该闭环驱动系统中,通过引入PI控制器消除了振动幅度控制的稳态误差。仿真结果很好地吻合了理论分析,理论分析结果可用于指导自激驱动系统的硬件实现。     

振动式微机械陀螺驱动环路数字AGC研究

对微机械陀螺系统的自激驱动环路进行了分析,并对数字处理电路中自动增益控制（AGC）模块进行了深入研究,给出了一种高控制精度的定点数字AGC算法。通过理论分析和模型仿真,结果表明AGC控制精度得到很大的提高,对陀螺驱动输出信号的幅度具有很好的控制效果,从而可以大大减小陀螺温漂及其他一些因素引起的不稳定性。最后给出了算法的直线逼近近似实现方法,能在的定点DSP当中很方便的实现。     

振动式微机械陀螺驱动环路数字自动增益控制研究

对微机械陀螺系统的自激驱动环路进行了分析,并对数字处理电路中自动增益控制(AGC)模块进行了深入研究,给出了一种高控制精度的定点数字AGC算法。通过理论分析和模型仿真,结果表明AGC控制精度得到很大的提高,对陀螺驱动输出信号的幅度具有很好的控制效果,从而可以大大减小陀螺温漂及其他一些因素引起的不稳定性。最后给出了算法的直线逼近近似实现方法,能在的定点DSP当中很方便的实现。     

基于相位控制的硅微机械陀螺驱动控制技术

全面分析、研究并实现了一种基于相位控制的硅微机械陀螺(Silicon micromechanical gyroscope, SMG)驱动控制技术. 分析了硅微陀螺驱动模态的动力学特性,阐述了相位控制方案的基本原理; 在此基础上建立了控制环路,采用自激振荡理论分析了其稳定性; 建立了环路的相位模型,引入特异因子实现相位控制误差到频率差 (工作频率与驱动模态谐振频率之差)的转换; 建立了对应于相位控制环路的频率模型,当环路滤波器为一阶模型时, 与传递函数为二阶的信号跟踪锁相环(Phase locked loop, PLL)不同,总的闭环模型仅为一阶; 最后基于FPGA平台,采用线性鉴相方式设计了数字化相位控制环路, 并结合幅值控制实现了双闭环驱动控制电路.测试结果表明, 该方案可实现硅微陀螺驱动端的高精度控制.     

硅微振动陀螺仪驱动器自激驱动研究

为了提高硅微机械陀螺仪的检测精度,稳定驱动振动速度的幅度和频率,采用了硅微机械陀螺仪自激驱动方式.该方式能够使驱动振动自动稳定在陀螺仪驱动模态的谐振频率上.同时,采用自动增益控制(AGC)保持恒定的驱动振动幅度.根据自激驱动电路原理和现有的陀螺样品,建立了陀螺仪驱动动力学方程的等效电路模型.设计、制作了自激驱动电路,仿真和实验结果表明该方法切实可行.     

微机械音叉陀螺驱动电路的研究

在分析微机械音叉陀螺的输出信号与驱动信号频率及幅度关系的基础上，提出对微机械音叉陀螺采用自激振荡闭环驱动方法，为微机械音叉陀螺的实验设计提供了理论基础，实验表明这种方法是可行的。     

一种高幅值稳定性的微机械陀螺闭环驱动电路

优化设计了一种闭环自激驱动电路,有效提高了微机械陀螺的驱动闭环控制精度.根据自激振荡振幅稳定性理论,对相角和增益解耦的闭环驱动系统幅值控制环路进行了分析,计算得到系统环路增益,推导出系统幅值达到最佳状态的环路参数,优化后陀螺的驱动力仅受控于一个可调变量.实验结果显示,改进后的自激振荡波形的均方差为0.0033 V,频率均方差为0.793 Hz,输出的幅值和频率的稳定性都得到了较大改善.对幅值控制环路的改进简化了电路调试,有效提高了陀螺系统的测量精度.     

Integrated model reference adaptive control and time-varying angular rate estimation for micro-machined gyroscopes

Owing to the imposed but undesired accelerations such as quadrature error and cross-axis perturbation, the micro-machined gyroscope would not be unconditionally retained at resonant mode. Once the preset resonance is not sustained, the performance of the micro-gyroscope is accordingly degraded. In this article, a direct model reference adaptive control loop which is integrated with a modified disturbance estimating observer (MDEO) is proposed to guarantee the resonant oscillations at drive mode and counterbalance the undesired disturbance mainly caused by quadrature error and cross-axis perturbation. The parameters of controller are on-line innovated by the dynamic error between the MDEO output and expected response. In addition, Lyapunov stability theory is employed to examine the stability of the closed-loop control system. Finally, the efficacy of numerical evaluation on the exerted time-varying angular rate, which is to be detected and measured by the gyroscope, is verified by intensive simulations.     

Compensation to imperfect fabrication and asymmetry of micro-gyroscopes by using disturbance estimator

Owing to the imposed coupling accelerations such as quadrature error and cross-axis perturbation, the micro-machined gyroscope could not be unconditionally retained at resonant mode. Once the preset resonance is not sustained, the performance of the micro-gyroscope is accordingly degraded. In this paper, a direct model reference adaptive control loop which is integrated with a modified disturbance estimating observer (MDEO) is proposed to guarantee the resonant oscillations at drive mode and counterbalance the undesired disturbance caused by quadrature error and cross-axis perturbation. The parameters of controller are on-line innovated by the dynamic error between the MDEO output and expected response. In addition, Lyapunov stability theory is employed to examine the stability of the closed-loop control system. At last, the efficacy of evaluation of the exerted time-varying angular rate, which is to be detected and measured by the gyroscope, is verified by intensive simulations.     

Analysis of parasitic feed-through capacitance effect in closed-loop drive circuit design for capacitive micro-gyroscope

The drive axis of a capacitive micro-gyroscope sensor forms an ‘electrical-mechanical’ resonator with closed-loop drive circuits when the gyro is in full operation. The parasitic feed-through capacitance, which exists between the driving and sensing electrodes of the sensor, induces two main negative effects: preventing the expected ‘electrical-mechanical’ oscillation and introducing an undesired high frequency ‘electrical’ oscillation. In this paper, mathematical expression of the critical parasitic feed-through capacitance allowing the occurrence of ‘electrical-mechanical’ oscillation is derived for the first time. Based on the derived expression, a conclusion that increasing the polarization voltage on the sensor mass be the only electrical way to increase the critical value of parasitic feed-through capacitance is revealed. Then with an implemented silicon chip for the drive circuit, the reason of occurring electrical oscillation is analyzed, and an effective solution to avoid the electrical oscillation referred as increasing the polarization voltage is proposed. Experiments on a capacitive micro-gyroscope prototype show that when the polarization voltage is increased from 10 to 18 V, the closed-loop drive circuit eliminates possibility of the electrical oscillation effectively. As a result, the proposed electrical oscillation solution has been verified.     

高精度数字式MEMS陀螺仪驱动闭环控制系统设计

为提高微机械陀螺检测灵敏度,设计了一种数字式微机械陀螺驱动闭环控制系统,该系统利用数字锁相环来实现陀螺驱动谐振频率和相位的跟踪,同时利用数字自动增益控制模块实现驱动幅值的稳定控制.该控制系统先是在MATLAB/Simulink平台上进行仿真验证,之后在基于FPGA的验证平台上进行验证.实验结果表明在该数字系统的控制下陀螺驱动起振时间大约为0.6 s,驱动幅值相对稳定性小于10×106,陀螺零偏稳定性达到10.448 °/hr.     

Sliding Mode Control for Flexible-link Manipulators Based on Adaptive Neural Networks

This paper mainly focuses on designing a sliding mode boundary controller for a single flexible-link manipulator based on adaptive radial basis function (RBF) neural network. The flexible manipulator in this paper is considered to be an Euler-Bernoulli beam. We first obtain a partial differential equation (PDE) model of single-link flexible manipulator by using Hamiltons approach. To improve the control robustness, the system uncertainties including modeling uncertainties and external disturbances are compensated by an adaptive neural approximator. Then, a sliding mode control method is designed to drive the joint to a desired position and rapidly suppress vibration on the beam. The stability of the closed-loop system is validated by using Lyapunov’s method based on infinite dimensional model, avoiding problems such as control spillovers caused by traditional finite dimensional truncated models. This novel controller only requires measuring the boundary information, which facilitates implementation in engineering practice. Favorable performance of the closed-loop system is demonstrated by numerical simulations.     

基于扩张状态观测器的发动机转速双闭环自适应控制系统设计

为较好控制发动机设备的实时转速水平,使其在不同压力水平下均能呈现理想化工作状态,设计基于扩张状态观测器的发动机转速双闭环自适应控制系统。根据双闭环电路的集成形式,连接发动机控制器与自适应传感器,利用隔离驱动芯片,更改观测器驱动管的作用频率周期,完成自适应控制系统的硬件执行环境搭建。在此基础上,深入分析扩张状态观测器的内部结构,以微分跟踪器作为切入点,选取关键的ESO参数,再借助扰动补偿向量,完成对扩张状态观测器的频域参数配置,联合相关硬件应用设备,实现基于扩张状态观测器的发动机转速双闭环自适应控制系统设计。实验结果表明,在扩张状态观测器作用下,发动机元件在不同压力水平下的实时转速水平均能得到有效控制,可使发动机设备保持较长时间的稳定工作状态。     

一种全新的硅微阵列陀螺仪

介绍了一种全新的硅微阵列陀螺仪的结构设计、模态仿真、电路闭环控制、数据融合方法和相关的的实验结果。基于热弹性阻尼理论的数值仿真,利用结构解耦的方法设计了硅微阵列陀螺仪的四质量块结构。利用ANSYS软件对硅微阵列陀螺仪的驱动模态和检测模态进行了仿真,仿真结果表明：硅微阵列陀螺仪共有四种不同的工作模态。根据静电力反馈原理,设计了基于数字锁相控制和数字闭环控制方法的控制电路。电路测试结构表明硅微阵列陀螺仪驱动模态的振动幅值的相对稳定性可以达到9×10-5。分析了硅微阵列陀螺仪的随机漂移特性,建立了漂移误差模型,并设计了卡尔曼滤波器以获取硅微阵列陀螺仪的随机漂移的最优估计。利用多传感器信息融合算法,硅微阵列陀螺仪的零偏稳定性可以提高10倍。