基于电磁铁附加线圈的悬浮间隙检测方法研究

Research on the Method of Levitation Gap Detection Based on Electromagnet With an Additional Coil

针对传统电涡流间隙传感器体积大、易受环境电磁场影响、无法工作在电磁铁磁路通道中、不能直接测量真实悬浮间隙、不便于悬浮控制等问题,提出一种基于电磁铁附加线圈的悬浮间隙检测方法,通过在电磁铁铁芯端部铺设附加线圈可实现间隙值的测量。首先,建立磁阻效应和涡流效应共同作用下的附加线圈等效阻抗数学模型,分析结构一体化对附加线圈的电磁特性影响,优化附加线圈结构;然后,设计间隙解调方案,分析电磁铁线圈与附加线圈之间的干扰抑制原理;最后,搭建实验平台,对该方法在悬浮间隙为1~15mm时进行静态性能测试,最大输出波动为±0.09mm,在常用工作间隙3~12mm范围内,线性度为2.11%。利用该方法进行悬浮球实时闭环反馈控制动态实验,验证基于电磁铁附加线圈检测间隙的可行性。

To address large volume,environmental electromagnetic field susceptibility,inability to work in the magnetic circuits,inability to directly measure the real levitation gaps,and inconvenience for levitation control of traditional eddy current gap sensors,this paper proposes a gap detection method using an electromagnet with an additional coil.The additional coil at the electromagnet core end can measure the gap.First,it establishes an equivalent impedance mathematical model for the additional coil considering magnetoresistance effect and eddy current effects.It analyzes how structural integration impacts the additional coil’s electromagnetic characteristics and optimizes the additional coil structure.Second,it designs a gap demodulation scheme and analyzes the principle of interference suppression between electromagnet and additional coils.Finally,it builds an experimental platform and tests the proposed method’s static performance for 1~15mm gap changes..The maximum output fluctuation is±0.09mm.Within the 3~12mm most common working gap.,the corresponding linearity is 2.11%.A levitated ball real-time closed-loop feedback control experiment verifies the proposed gap detection method using an electromagnet with an additional coil.