A New Metal Detection Method Based on Duffing Chaotic System

Abstract

In order to increase the sensitivity of a metal detector, this paper first applies a chaotic detection system-Duffing oscillator to metal detectors. To establish a Duffing oscillator suitable for metal detectors, this paper computes two Lyapunov characteristics exponents of Duffing oscillator by RHR algorithm, so that the two Lyapunov characteristic exponents offer quantitative criteria for chaos, and help to get the threshold in critical state more accurately. The threshold will be as the amplitude of the internal reference signal in the simulation model. Meanwhile, a corresponding simulation model of Duffing oscillator is made by the Simulink of Matlab. Simulation results indicate that Duffing oscillator is very sensitive to sinusoidal signal in high frequency cases. Experimental results show that the measurable diameter of metal particles is less than 1.5mm. Namely this method can improve the sensitivity of a metal detector effectively.