【作者】 李强；

【导师】 李德才；

【作者基本信息】 北京交通大学 ， 机械设计及理论， 2012， 博士

【摘要】 本文根据一种新型磁性液体传感器原理设计了一种磁性液体加速度传感器；磁芯采用磁性液体悬浮的永磁体；回复力由一对永磁体产生；信号由一对电感式线圈检测。根据磁性液体的表面应力张量,理论研究了磁性液体悬浮力的大小,得出了磁性液体自悬浮表达式,理论证明了实验采用的永磁体能被磁性液体悬浮,得出了实验采用磁性液体的相对磁导率应大于1.02的结论；根据永磁体的磁力计算原理,利用圆柱形永磁体永磁圆盘叠加模型和等效电流线圈模型计算了圆柱形永磁体产生的场,得到了两个圆柱形永磁体间磁力,对采用一对永磁体产生的磁力与磁芯位移的关系进行了数值计算,得出了在不同回复距离时,磁力与磁芯位移的关系,加速度与磁芯位移的关系；对差动电感式传感器的输出电压进行了理论分析,得出传感器输出电压表达式。对线圈的结构参数进行了设计；对传感器的磁芯材料进行了选择；对电源电压和频率进行了确定；设计了检测传感器信号的差动式电桥电路,设计了具有放大、整流功能的信号处理电子电路；用Labview软件设计了数据采集卡和计算机接口程序。搭建了具有信号处理和数据采集功能的传感器实验平台。分析了传感器的结构参数对输出特性的影响；在搭建的传感器实验平台上,对磁性液体加速度传感器采用的回复距离、磁性液体种类、磁性液体体积、磁性液体物理性能参数、磁芯的尺寸等与输出电压的关系进行研究,实验数据与数值模拟基本符合；分析了传感器的部分静态和动态性能,实验数据与理论分析符合较好。图95幅,表22个,参考文献126篇。更多还原

【Abstract】 This paper presents ferrofluid acceleration sensor according to a new principle of ferrofluid sensor, magnetic core is made up with a permanent magnet levited by ferrofluids, and its restoring force is derived from a couple of permanent magnets, signal is detected by a couple of inductive coils.According to the magnetic surface stress tensor of ferrofluid, ferrofluid levitation force is theoretical studied, the expression of self-levitaion of ferrofluid is obtained, self-levitation of magnet in ferrofluid is theortical proved, the relative permeability of ferrofluid, which used in experimental research, should be greater than1.02. According to magnetic force calculation principle, based on model of disc stack of cylindrical magnet and equivalent current coil model of cylindrical magnet, the magnetic field of cylindrical magnet is calculated, magnetic force between two cylindrical magnets is obtained, the relationship between restoring force and magnetic core displacement is studied by numerical computation, the relationship between magnetic force and magnetic core displacement is obtained under different restore distance, and the relationship between acceleration and magnetic core displacement is obtained under different restore distance. Output voltage of differential inductive sensor is theoretical studied, the output voltage of sensor is obtained.Structural parameters of coil are designed. Magnetic core material is selected. Supply voltage and frequency are confirmed. Differential bridge circuit is designed, which is signal detected circuit of sensor. Electionic circuit of signal processing is designed, signal processing electionic circuit has amplification and rectifier functions. Interface program between data acquisition card and computer is designed by Labview soft. Differential bridge circuit, electionic circuit of signal processing, data acquisition card, Labview soft and computer are assembled in sensor experimental platform.The relationships between structural parameters of sensor and output characteristics are analysed. The relationships among output voltage and restoring distance, type of ferrofluid, volume of ferrofluid, physical parameters of ferrofluid, dimension of magnetic core of ferrofluid acceleration sensor are studied on sensor experimental platform, expermential data are in good agree with numerical simulation, the partial static and dynamic performances are studied, expermential data are in good agree with theory analysis. There are95figures,22tables,126references on this paper.更多还原