漏磁传感器励磁结构影响因素分析及优化设计

Influences and Optimization of Excitation Structure of Magnetic Flux Leakage Sensor

漏磁检测中励磁结构的磁化能力是影响漏磁传感器缺陷检测能力的一个重要因素。根据交流漏磁检测原理,建立二维漏磁检测参数化有限元仿真模型,研究磁心的形状和尺寸、励磁线圈的位置和绕组长度、磁屏蔽层厚度等励磁结构参数对漏磁检测信号的影响。同时,将参数化有限元分析与遗传优化算法相结合,发展一种励磁结构尺寸参数的有限元模拟遗传优化设计方法,实现了漏磁传感器中磁极间距与磁极宽度等关键尺寸的优化。仿真及检测试验结果表明,传感器的励磁结构参数对漏磁检测结果具有很大影响,优化后的励磁结构可有效提高漏磁传感器的缺陷检测性能。提出的基于参数化有限元的遗传优化方法为漏磁检测中其余影响参数的优化提供了可行的参考方法。

The magnetizing ability of excitation structureshas great influence on the detectability of magnetic flux leakage sensor.According to the method of AC magnetic leakage detection, a parametric finite element model of magnetic flux leakage detection is established. The influences of the shape and size of the magnetic yoke, the position of the exciting coil, the winding length and the thickness of the magnetic shielding layer on the detection signal are investigated. In addition, an optimization method of the size of the excitation structure is developed by combining parametric finite element analysis with genetic algorithm.The distance between the magnetic poles and the width of the magnetic pole is optimized. The simulation and test results show that the excitation structure has a great influence on the results of magnetic flux leakage testing, and the optimized magnetic excitation structure is helpful to improve the detection performance of the magnetic flux leakage sensor. The proposed optimization method provides a feasible method for improving the performance of magnetic flux leakage sensors.