Eddy Current Sensor With Multiple Spatial Degrees of Freedom for Concentrating Magnetic Fields
Gang Wang, Yuan Zhong, Qi Xiao, Qiangxin Li
Abstract
The development of Koch curve fractal geometry provides valuable ideas for the structural design of sensor. Conventional eddy current sensor (CECS) can not effectively concentrate electromagnetic fields energy and have low detection sensitivity. The eddy current sensor (ECS) based on Koch curve fractal geometry can change the distribution of electromagnetic fields in space. Therefore, based on Koch curve fractal geometry, a novel ECS with multiple spatial degrees of freedom (SDOF), including torsion structure of x-y plane and inclination angle of y-z plane, for concentrating magnetic fields (MSECS) is developed in this paper. The proposed multiple SDOF are analyzed and optimized by finite element analysis. An energy spectrum function is proposed to describe the distribution of eddy current. The simulation results show that MSECS can concentrate electromagnetic fields and improve energy transfer efficiency. Defect detection experiments are conducted on prefabricated defective steel plates, which show that MSECS has better performance of detection.