高灵敏低压电磁感应式滑油磨屑传感器

High-sensitivity, low-voltage lubricating oil wear debris sensor based on electromagnetic induction

提出了一种高灵敏低压低功耗的三线圈电磁感应式磨屑检测方法。理论推导了金属磨屑穿过线圈组引起的感应电压变化的表达式,并据此对线圈组的几何参数进行了优化。通过在激励和感应线圈两端分别并联和串联恰当容值的电容实现双LC谐振,以获得更高的激励电流和感应电压。实验验证了在108 kHz、5 Vpp的正弦信号激励下,上述两种方法同时使用能够较大幅度提高信噪比,在相敏检波电路之后未使用放大电路的情况下能够清晰地检测到低至150μm的铁质颗粒,而此时激励线圈的有功功率仅为1.12 mW。所设计的传感器能够在平衡低功耗的同时获得高灵敏度,其优化思路对于同类型传感器优化具有借鉴意义。

A three-coil electromagnetic induction wear debris detection method with high sensitivity,low voltage and low power consumption is proposed.The induced voltage change caused by wear debris passing through the coil set is theoretically deduced,and the geometric parameters of the coil set are optimized based on the derivation.The dual LC resonance is realized by connecting capacitors of appropriate capacitance values to both sides of the coil set in parallel and in series to obtain higher excitation current and induced voltage.Experimental results show that under the excitation of sinusoidal signal of 108 kHz and 5 Vpp,the above two methods can greatly improve the signal-to-noise ratio,and ferrous debris as small as 150μm can be clearly detected without using any amplifier circuit after the phase sensitive demodulation circuit,the active power of the excitation coil is only 1.12 mW.The designed sensor can achieve high sensitivity while the low power consumption is balanced.The optimization idea can be used as a reference for the optimization of the same type of sensors.