Research on Parameter Characteristics of Metal Detection System Based on Pulse Electromagnetic Induction

This paper mainly analyzes the important parameters of the metal detection system based on pulse electromagnetic induction. The loos model of the coil system is established in the first place. According to the analysis of the equivalent circuit model, the mathematical model of the coil system is proposed, combining with Thevenin's theorem and Laplace's transformation. With the excitation voltage source as the input signal and the induction voltage of the metal conductor as the output signal simultaneously, the transfer function between them is built. Furthermore, by changing the important parameters in the system, such as resistance or capacitance, the transfer function will change, resulting in the change of output signal. Based on the above analysis, this paper proposes that the maximum value of the absolute value of the induced voltage is taken as the index, then the larger its value is, the more excellent the corresponding parameters will be. Conclusively, input the square wave pulse by the means of simulation software as well as change the parameters to be studied with the adoption of the control variable method, then analyze the impacts of the parameters on the system through the simulation results, so as to select the optimal parameters and make the detection system optimal.