磁致伸缩压力传感器设计及其输出特性

摘要

研究了铁镓合金(Galfenol)的磁致伸缩特性,提出一种基于Galfenol的新型磁致伸缩压力传感器,以实现机器人的触觉力精确感知.该传感器利用磁致伸缩逆效应将压力转换为电压信号,从而完成对压力的精确测量.设计、制作了磁致伸缩压力传感器,采用双永磁体回形磁路优化了压力传感器的磁场.对传感器进行了理论分析与实验研究,讨论了偏置条件、外压力等因素对输出电压峰值的影响.实验结果表明,在偏置磁场为4.8 kA/m、施加的压力为2.5 Hz、6 N时,传感器的输出电压峰值达16 mV,且输出电压峰值与压力呈较好的线性关系.研制的传感器具有结构简单、线性度好、反应速度快等特点,可以满足机器人触觉感知的需求,也可应用于其他领域的压力测量.%Magnetostrictive characteristics of Galfenol were researched and a new type of magnetostrictive pressure sensor based on the Galfenol was proposed to implement the accurate perception of tactile sensation for robots.The sensor converts a pressure signal into a voltage signal based on magnetostrictive inverse effect to implement the accurate measurement of the pressure.The magnetostrictive pressure sensor was designed and fabricated, and the magnetic field of pressure sensor was optimized by a magnetic circuit of double permanent magnets.Then, the sensor was analyzed theoretically and investigated experimentally, and the influences of bias condition, external pressure and other factors on the peak value of output voltage were discussed.The results show that when bias magnetic field is 4.8 kA/m and applied pressure is 2.5 Hz and 6 N, the peak value of output voltage reaches 16 mV and the peak value of output voltage has better linear relation with the pressure.The developed sensor is characteristics by simple structure, good linearity, and a quick response speed.It meets the requirements of tactile sensation of robots and is suitable for the pressure measurement in other fields.