【作者】 王欢；

【导师】 吴伯农； 李德才；

【作者基本信息】 北方工业大学 ， 机械工程领域（专业学位）， 2019， 硕士

【摘要】 磁性液体兼具磁性和流动性两大物理特性,基于这两个独特的物理性质产生了磁性液体倾角传感器。利用惯性质量块的微小位移带来的线圈电感变化,进行倾斜角度测量。该磁性液体倾角传感器具有成本低、构造简单、灵敏度高的特点,可以满足传感器性能要求。本文设计了基于二阶浮力原理的倾角传感器,探究了影响传感器性能的各个因素。本论文从理论上推导了圆柱形磁铁在空间中的磁场方程、二阶浮力理论以及感应线圈的电感公式,并建立了磁性液体倾角传感器的物理模型,利用COMSOL和ANSYS有限元软件对磁场进行直观描述,利用模型计算二阶浮力。搭建二阶浮力实验台,对复合磁芯在磁性液体中受到的二阶浮力值进行测量;搭建了电感实验台,测量了复合磁芯在线圈内部的位置对电感值的影响。结合电感实验和二阶浮力实验,对传感器的总体设计进行优化,选择适合的复合磁芯,搭建试验台测量传感器的静态输出性能。得到的结论为:1.通过对二阶浮力理论进行推导,发现复合磁芯受到的二阶浮力不仅为它提供了向上的悬浮力,也为复合磁芯提供了回复力,使传感器处于水平位置时复合磁芯可以回到中心位置。2.通过参数化建模,发现复合磁芯内部棒材使用铁芯时模型磁场强度有明显加强。为了能够深入理解二阶浮力原理,用有限元分析方法得到磁力线图,能够直观看到磁场强度变化趋势。3.复合磁芯受到的二阶浮力会随着磁液量的增多而增大,选中的三个复合磁芯的方案中,圆柱形磁铁受到的二阶浮力最大,带有30mm铁芯的圆环磁铁受到的二阶浮力值最小。4.通过电感实验,得到线圈电感值与对应的插入复合磁芯的深度的变化曲线,并进行进一步实验,得到铁芯长度与线圈电感变化的关系曲线。发现当铁芯长度越长,复合磁芯插入线圈时曲线斜率越大,也就是灵敏度更高。5.测试传感器的性能,得到输出电压与传感器倾斜角度的关系,从拟合曲线中可以看出,复合磁芯带有铁芯的传感器在一定范围内具有更好的灵敏度。更多还原

【Abstract】 The magnetic liquid combines the two physical properties of magnetism and fluidity,and based on these two unique physical properties,a magnetic liquid tilt sensor is produced.The tilt angle is measured by the change in the coil inductance caused by the small displacement of the inertial mass.The magnetic liquid tilt sensor has the characteristics of low cost,simple structure and high sensitivity,and can meet the performance requirements of the sensor.In this paper,a tilt sensor based on the second-order buoyancy principle is designed to explore various factors that affect the performance of the sensor.In this thesis,the magnetic field equation of the cylindrical magnet in space,the second-order buoyancy theory and the inductance formula of the induction coil are theoretically derived.The physical model of the magnetic liquid inclination sensor is established.The magnetic field is visualized by COMSOL and ANSYS finite element software.Description,the second-order buoyancy value is calculated according to the model.A second-order buoyancy test bench was built to measure the second-order buoyancy value of the composite magnetic core in the magnetic liquid.An inductance test bench was built to measure the influence of the position of the composite core inside the coil on the inductance value.Combining the inductance experiment and the second-order buoyancy experiment,the overall design of the sensor is optimized,and a suitable composite core is selected to build a test bench to measure the static output performance of the sensor.The conclusions reached are;1.By deriving the second-order buoyancy theory,it is found that the second-order buoyancy of the composite core not only provides it with upward levitation force,but also provides a restoring force for the composite core,so that the composite core can be placed in the horizontal position.Go back to the center.2.Through parametric modeling,it is found that the magnetic field strength of the model core is significantly enhanced when the core of the composite core is iron core.In order to understand the second-order buoyancy principle in depth,the magnetic field diagram is obtained by the finite element analysis method,which can visually see the trend of the magnetic field strength.3.The second-order buoyancy of the composite core will increase with the increase of the amount of magnetic fluid.In the scheme of the three composite cores selected,the cylindrical magnet receives the second-order buoyancy,and the circle with 30mm core The ring magnet receives the second-order buoyancy value to a minimum.4.Through the inductance experiment,the curve of the inductance of the coil and the corresponding depth of the inserted composite core is obtained,and further experiments are carried out to obtain the relationship between the length of the core and the change of the inductance of the coil.It is found that the longer the core length,the greater the slope of the curve when the composite core is inserted into the coil,that is,the sensitivity is higher.5.Test the performance of the sensor and obtain the relationship between the output voltage and the tilt angle of the sensor.It can be seen from the fitting curve that the sensor with the core of the composite core has better linearity within a certain range.更多还原