磁悬浮转子微陀螺及其悬浮力与稳定性的分析

磁悬浮转子微陀螺是一种集经典陀螺的工作原理与易实现微加工批量生产的特点于一体,可望得到高准确度的微陀螺。它是基于电磁场原理得以悬浮、旋转以及稳定;以ANSYS5.6有限元分析软件包为工具分析了悬浮线圈中的电流幅值和线圈宽度对悬浮力的影响规律;分析了磁悬浮转子微陀螺的运行稳定性,验证了稳定线圈能使微转子稳定运行,从而磁悬浮转子微陀螺的设计得以论证。进行的数值计算为优化微陀螺的结构设计提供依据。     

电磁悬浮转子微陀螺悬浮稳定性分析

电磁悬浮转子微陀螺(MGELR)是一种新型的角速率传感器,它和传统机械陀螺具有相同的工作机理.MGELR有望成为具有高精度的微陀螺.对于MGELR来说,转子的稳定悬浮是极为重要的.文中对微转子的稳定悬浮进行了全面的研究.详细分析并给出线圈、转子直径、电流幅值、悬浮高度等因素对微转子悬浮稳定性的影响.文中提出边界效应理论来解释微转子偏心所带来的侧向力.试验结果进一步论证了分析的正确性.文章最后得出稳定悬浮所应满足的条件.文章的研究内容为MGELR的结构设计提供理论基础.     

磁悬浮转子微陀螺旋转驱动电路设计

介绍了基于MEMS技术的磁悬浮转子微陀螺的基本原理,重点对旋转的原理进行讨论,给出相应实现方案的指标分析和系统设计,并进行了实验.经过驱动后,微陀螺可以得到3 000 r/min的旋转效果,并对旋转的转速和力矩进行了分析.     

磁悬浮转子微陀螺的电容检测系统分析和实现

介绍了一种新型磁悬浮转子微陀螺的电容检测方案,其特点是检测定子上径向分布的电容极板和悬浮转子形成差动电容的变化.检测电路为基于相关检测原理的交流电容电桥的方法.电路实现中采用积分电荷放大器作为前置级,对其输出和噪声进行了深入的分析.之后,前置级的输出信号经过低噪声放大器进行放大,再通过带通滤波以及相关解调等电路实现检测系统需要的输出幅值和信噪比.实验证明,实现的检测系统对角度输入有较好的线性响应,角度分辨率达到0.1°,即可检测到的电容变化约为1fF.     

静电悬浮转子微陀螺悬浮控制系统的研究

针对一种新颖的基于MEMS技术的静电悬浮转子微陀螺,提出了悬浮控制系统的原理和设计,并着重对z轴悬浮控制系统的设计进行了分析,建立了Z轴方向悬浮控制系统的数学模型,通过分析扰动力对转子位移的影响,得出PID(比例-积分-微分控制)参数决定动态刚度,通过仿真结果可以看出,采用反馈线性化可补偿系统的负刚度特性,结合变预载控制实现转子的快速准确定位,为后续的旋转和加矩控制提供良好的条件.     

混合磁悬浮轴承转子系统的仿真分析

通过ANSYS对UG中所建立的转子的三维实体模型进行有限元分析,生成了柔性转子的模态中性文件,将其导入ADAMS中分别建立了轴向永磁、径向四自由度电磁悬浮和轴、径向三自由度永磁、其余两径向自由度电磁悬浮的五自由度混合磁悬浮轴承柔性转子系统模型,采用基于接口的方法在MATLAB和ADAMS环境下对系统进行了起浮和旋转联合仿真,并根据仿真结果对设计参数进行了优化,可为混合磁悬浮轴承转子系统的设计与研究提供参考。     

磁悬浮系统的极点配置控制器设计研究

单自由度磁悬浮1球系统是多自由度磁悬浮控制研究基础,本文在分析磁悬浮系统构成及工作原理的基础上,建立了单自由度磁悬浮系统的数学模型,并将非线性模型进行了线性化。采用极点配置法设计了PI线圈电流控制器和PIV-前馈小球位置控制器,利用MATLAB／SIMULINK和RTX实时系统进行了实验,实验结果表明,小球可以稳定地悬浮在期望位置,并且具有一定的抗干扰能力。     

基于DSP的左心室辅助装置磁悬浮轴承位移测量

针对左心室辅助装置磁悬浮轴承振动特性,设计了以DSP为核心控制器的测控系统。介绍了电涡流位移传感器的工作原理,编写了采集控制程序以及A/D校正算法,采集了轴承动态情况下的位移数据,并用MATLAB进行了实验数据分析得到转子动态位移特性,为后续控制转子稳定悬浮工作提供了数据支持。     

基于DSP的静电悬浮微陀螺模拟伺服系统的研究

采用TI公司的浮点式TMS320VC33 DSP开发系统,用于静电悬浮转子微陀螺的悬浮控制试验。介绍了微陀螺控制系统的硬件结构和软件设计,搭建了Simulink控制系统模型,并利用劳斯判据在理论上推导了PID参数的选取范围。研究了不同频率的正弦激励信号对系统输出的影响;计算了其主要电气参数,并设计了微陀螺的开环、闭环和刚度性能指标。最后,给出了静电悬浮转子微陀螺系统初步的悬浮控制结果。     

磁悬浮球旋转控制系统

磁悬浮球是磁悬浮列车，磁悬浮轴承，磁悬浮飞轮储能系统，磁悬浮发射等一切磁悬浮研究的基础。同时也是闭环和非线性控制研究很好的平台。本文在分析磁悬浮球控制原理的基础上得出其悬浮、旋转数学模型，给出了使其悬浮、旋转的控制方案和仿真、实验结果。     

抗磁悬浮石墨转子理论及仿真分析

研究了一种由热解石墨转子、永磁体结构以及底板构成的抗磁悬浮结构,通过对石墨转子叶片施加氮气流使其运动.利用有限元软件COMSOL Multiphysics建立仿真模型,并且将仿真结果与实验结果相对比.研究表明,未受氮气流作用时,石墨转子仿真悬浮高度为130 μm,实验测得悬浮高度为132 μm,误差为1.5%;实验测得氮气流速小于21.45 sccm时,石墨转子在永磁体上方轻微摆动,而未转动,氮气流速达到21.45 sccm时,石墨转子转速稳定在120 r/min~130 r/min之间与仿真结果接近.通过对比仿真结果与试验数据得出石墨转子加工质量,实验环境对石墨转子的运动性能有一定影响,该抗磁悬浮结构有望用于微型电机和非接触式传感器中.     

An innovative micro-diamagnetic levitation system with coils applied in micro-gyroscope

This paper presents design, simulation, and fabrication, levitation experiment of a micro-diamagnetic levitation system with coils. This micro-system module can be applied in the micro-gyroscope system because of its stable levitation of disc. The device configuration consists of three main parts: micro-disc, stator and permanent magnet (PM). Micro-disc is stably levitated on the top of the stator and PMs due to stable diamagnetic force produced between PMs and pyrolytic graphite disc. Simulation on levitation shows the situation of diamagnetic force at the centre, and offset from centre. Finally, from the levitation experiment we can see clearly the influence on levitation height of PM thickness and micro-disc thickness. As far as micro-gyroscope is concerned, coils analysis shows relationship between rotation torque and current frequency by Ansoft Maxwell, and a rotation circuit also is designed by the authors in the end of the paper.     

Modeling and simulation of levitation control for a micromachined electrostatically suspended gyroscope

This paper presents a novel micromachined electrostatically suspended gyroscope (MESG) based on non-silicon micro electro mechanical systems technology, which can measure dual-axis angular velocity and tri-axis linear acceleration. The position of the rotor is detected capacitively and controlled electrostatically. In order to levitate the rotor along the Z axis, a levitation control model based on integrated control strategy for the MESG is presented. The damping coefficient is calculated by finite element analysis and deduced by analytical solution. According to the analysis of the levitation control force of the rotor, a three-degree-of-freedom close-loop control model is constructed. The theoretical relationship between the proportional integral derivative control parameters and stiffness properties is deduced. Initial levitation simulation result shows that the control principle is reasonable, which shows quick-response performance and global stability. Furthermore, digitally controlled levitation circuits have been designed.     

基于抗磁悬浮的气流能量采集器

研究了一种由外壳、提升磁体、上热解石墨板、线圈、永磁体转子和下热解石墨板构成的气流能量采集器,自由悬浮于两热解石墨板之间的永磁体转子可在外界气流的作用下转动,并在线圈中产生感应电压。采用有限元软件COMSOL Multiphysics 5.3和ANSYS Maxwell 16.0建立仿真模型,对能量采集器的悬浮特性、驱动特性和输出特性进行仿真分析通过实验验证,发现当喷嘴为83°时转子所受的气流驱动力矩最大;实验测试永磁体转子悬浮高度56.5 mm,与仿真高度57.5 mm误差仅为1.77%;能量采集器稳定工作的气流量范围为137 sccm^733 sccm,最大输出电压可达160 mV。     

Design and experiment of an electromagnetic levitation system for a micro mirror

In this paper, the design and characterization of a contactless electromagnetic levitation and electrostatic driven microsystem is presented, which has applications for example for large scale angle rotation micro mirrors. The proposed design can levitate a fabricated aluminum micro rotor which can incorporate a mirror and control it to rotate around the vertical axis within the range of ± 180°, which enlarges the scanning angle dramatically compared with conventional torsion micro mirrors. The rotation angle of the micro rotor is detected by the change of capacitance and controlled by the electrostatic force produced by variable capacitors. The levitation of the micro rotor is realized by utilizing electromagnetic inductions. The rotation is achieved through electrostatic forces generated by a digital controller. The hybrid system design for a micro rotor, combining magnetic and electrostatic forces is introduced. The digital control strategy is based on a PID controller with bias voltage. The detection interface circuit, which is based on frequency multiplexing, is also presented in this paper. It has been experimentally shown that the proposed design can levitate a 1.65 mm radius and 8 µm thickness aluminum micro rotor to 100 µm height with 20 MHz frequency and 0.5A p-p input current. Square and slope wave input experiments were carried out. The experimental results show that the control principal is in good agreement with the simulation models and this applies as well to the time-response performance and stability.

     

Electromagnetic levitation micromotor with stator embedded (ELMSE): levitation and lateral stability characteristics analysis

The adhesion, friction, wear in micro system or MEMS is more significant than those in macro system. The levitation or suspension technique is one of the effective techniques to eliminate the adhesion, friction, wear caused by the surfaces contact. The electromagnetic levitation micromotor with stators embedded (ELMSE) is a kind electromagnetic eddy current levitation system, which has special structure including the double sided stator and the hollow annular rotor. Different from the electromagnetic eddy current levitation system with single sided stator, ELMSE has good stability in the vertical and lateral directions. Using the finite element method, the levitation characteristics and lateral stability characteristics are analyzed. The influence of structural parameters and electric parameters on the vertical stiffness and the lateral stiffness has been analyzed and optimized in the paper. The analysis result of the paper provides theoretical reference for the optimal design of ELMSE.     

Modeling and experimentation of a passive low frequency nanoforce sensor based on diamagnetic levitation

This paper is focused on the study of a new low frequency micro and nanoforce sensor based on diamagnetic levitation. The force sensitive part is a 10-cm long macroscopic capillary tube used as a levitating seismic mass. This tube presents a naturally stable equilibrium state with six degrees of freedom thanks to the combination of diamagnetic repulsive and magnetic attractive forces. It is only used as a one-direction force sensing device along its longitudinal axis. This force sensor is passive. The force measurement is based on the displacement of the capillary tube and in steady-state this displacement is proportional to the force. This sensor is characterized by an under-damped second-order linear force-displacement dynamic which remains linear on several hundred micrometers and can thus measure a wide range of microforces. Because of the magnetic springs configuration used, the capillary tube presents a horizontal mechanical stiffness that can be adjusted between 0.01 and 0.03 N/m (similar to the stiffness of a thin AFM cantilever). The measurement range typically varies between ±50 μN. Bandwidth is 4 Hz. The resolution depends on the sensor used to measure the capillary tube displacement and on noises induced by environmental conditions (ground and air vibrations). The resolution typically reached with a STIL confocal chromatic sensor is 5 nN inside a test chamber located on a anti-vibration table. This study is illustrated by a pull-off force measurement.     

Motion error correction for non-contact ultrasonic motor driven by multi-layered piezoelectric actuators

An active non-contact ultrasonic motor with the micro positioning abilities of a rotor was proposed and performances were tested. The stator had a simple cylindrical form, which enabled low manufacturing costs. A resonant frequency of 22.2 kHz at eighth flexural mode of vibration was observed. With appropriate assembly and operation of piezoelectric actuators, the flexure vibration of the stator travels in the circumferential direction. The component of the stator deformation in radial direction creates an air film pressure higher than ambient thereby suspending the rotor. Simultaneously, the component that propagates in the circumferential direction rotates the rotor based on acoustic viscous flow. It was experimentally confirmed by electrical conduction test that the rotor rotated with levitation from stator. In addition, piezoelectric actuators around the stator exciting the deflective vibration could make contact-free micro positioning abilities of the rotor with a minimum step width of 0.15 μm.     

无轴承扰动补偿悬浮系统的稳定性分析与验证

目前, 无轴承磁悬浮系统多采用PID等经典控制策略, 然而由于外界扰动、参数摄动等诸多原因, 难以实现高性能的悬浮控制. 本文针对上述问题, 通过在传统PID悬浮控制系统中增加扩张状态观测器, 对悬浮力扰动进行实时补偿, 从而建立基于扩张状态观测器的无轴承悬浮控制系统. 其中, 根据扩张状态观测器对综合扰动进行观测的基本原理, 构建了系统数学模型, 并对其稳定性进行了分析. 在此基础上, 对观测器参数调节的选取原则和稳定域的参考范围进行了理论分析, 从而提出了一套无轴承悬浮控制系统参数整定方案. 此外, 本文还结合模型中主要参数的物理意义, 进一步完善了非线性扩张状态观测器参数的设定原则. 最后, 通过仿真验证了扩张状态观测器对无轴承悬浮系统扰动抑制的作用, 以及所述参数整定方案的正确性.