基于隧道磁电阻(TMR)效应的齿轮传感器设计与性能

Design and performance of gear sensor based on TMR effect

采用有限元软件对TMR齿轮传感器进行模拟仿真,对比分析后发现凹槽形长方体磁体可以有效优化齿轮传感器的磁路结构。根据齿轮传感器的特点和应用,分析了相关的TMR性能参数,采用最小电阻间距0.25mm的TMR芯片结构设计,以惠斯通电桥为基本的连接方式,制备出一系列基于TMR效应的齿轮传感器。通过示波器采集传感器模拟输出,全面分析了TMR芯片电阻间距、齿轮周期间距、空气间隙等因素对输出的影响,结合方波输出信号,对传感器进行功能性验证。结果表明,此传感器具有信噪比高、响应频率高、温度特性好、大的空气间隙等特点,可实现对齿轮的速度、移动方向、缺齿等方面的检测,具有广阔的工业应用前景。

TMR gear sensor was simulated by FEM software. Groove-shaped magnet can effectively optimize the magnetic circuit structure of TMR gear sensor. According to the feature and applications, the parameters of TMR were measured. A series of TMR gear sensor of Wheatstone bridge layout was prepared with 0.25mm minimum resistance pitch . By using the output from oscilloscope, the influence of TMR pitch, gear pitch and air gap on the output and performance of gear sensor was analyzed comprehensively. The result shows that, the sensor has such characteristics as high SNR, high frequency response, good temperature dependence, large air gap, and can be widely used for detecting speed, direction and missing of gear in industrial applications.