Fe-Ga磁致伸缩位移传感器驱动电流位置调整与回波速度校正

通过对传统Fe￣Ga磁致伸缩位移传感器驱动脉冲电流输入端位置的改进,降低了驱动脉冲电流噪声对检测线圈输出电压的影响,并使检测线圈输出电压信噪比由15.5 dB提高至23.7 dB。基于应力波无阻尼反射原理提出一种新的回波速度校正法,确立了回波速度与波导丝长度、应力波传播时间、反射波传播时间的数学关系,并给出此表达式适用的驱动脉冲电流频率范围。制作了样机,通过实验验证了此方法最大位移测量误差减小到原来的1/5,为Fe￣Ga磁致伸缩位移传感器输出性能研究提供了理论依据。

Adjustment of Drive Current Position and Correction of Echo Wave Speed of the Fe-Ga Magnetostrictive Displacement Sensor

The input position of the drive pulse current in traditional Fe￣Ga magnetostrictive displacement sensor is improved to reduce the effect of noise from the driving pulse current to the output voltage of detection coil. And the SNR of the output voltage is increased from 15.5 dB to 23.7 dB. A new method which is based on the principle of the stress wave is reflected undamped to correct the echo velocity. It establishes the mathematical relationship between the echo velocity,waveguide length of wire, the stress wave propagation time and the reflected wave propagation time. Moreover,the range of drive pulse current frequency has been given by this method. Based on the experimental results,a new type of Fe￣Ga magnetostirctive displacement sensor is fabricated and it performs well. The experimental results verify that the maximum measurement error is reduced to 1/5 of the traditional ones. They provide important theoretical guidance in improving the output performance of Fe￣Ga Magnetostrictive displacement sensor.