Optimizing Coil Structural Parameters to Enhance the Sensitivity of Wear Particle Sensor

If wear particles generated during the operation of automobile engines are not monitored in time, they will contaminate the lubricating oil, leading to system failures or even accidents. Therefore, real-time wear particle monitoring is crucial for the stable operation of engines. Among mainstream wear particle monitoring sensors, the three-coil inductive sensor demonstrates significant application potential due to its ability to distinguish wear particle materials and strong resistance to environmental interference. However, its insufficient sensitivity to small-diameter wear particles limits further performance improvement. This paper takes the three-coil inductive wear particle monitoring sensor as the research object. First, a mathematical model of the sensor's operation is established based on the law of electromagnetic induction, clarifying the relationship between structural parameters (such as channel radius, turns, coil spacing, and length) and the peak induced voltage. Subsequently, Multiphysics simulation software is employed to quantitatively analyze the influence of each structural parameter on the induced voltage, identifying directions for parameter optimization. Furthermore, orthogonal experiments are conducted to optimize discrete parameters, determining optimal levels for key parameters such as channel radius and coil spacing. Then, the simulated annealing algorithm is applied to achieve precise optimization of continuous parameters, ultimately obtaining the optimal combination of coil structural parameters. Experimental validation based on the optimized parameters shows that the peak-to-peak induced voltage for 1000 μm wear particles measured by the sensor optimized with the simulated annealing algorithm reaches 2.43 V, which is approximately 41 times higher than the 0.06 V observed before optimization. Additionally, the optimization effect of the simulated annealing algorithm further improves by 38.86% compared to the orthogonal experiment. In addition, experimental tests were also carried out on small-diameter abrasive particles of 100 μm, with the peak-to-peak value of the induced voltage reaching 0.38 V. The results confirm that this coil structural parameter optimization method effectively enhances the sensor's sensitivity to small-diameter wear particles, providing a theoretical basis and technical support for the structural design and performance improvement of three-coil inductive wear particle monitoring sensors.