Wireless sensor using nonlinear ultrasonic wave modulation technique

Abstract

The present invention relates to the security diagnostics method of structure, it is characterised in that including：The step of applying all different frequency signals and vibrating structure；The step of by data signal is converted to by above-mentioned vibration and the response of caused above-mentioned structure；From above-mentioned data signal remove said frequencies signal higher harmonics response and linear response and synchronize demodulation, the step of so as to generate primary modulation signal；The frequency of the above-mentioned different frequency signal of consecutive variations and extract primary modulation signal, and according to frequency and combine primary modulation signal to generate the first the Sideband Spectrum (first sideband spec trogram) the step of；And according to above-mentioned first the Sideband Spectrum, judge that above-mentioned structure has flawless step, even if the power for being applied to the ultrasonic wave of structure also can critically determine whether damage, therefore can reduce power consumption significantly less than conventional art.