The Research On Vibration Character Sensor

China locates in the joint of the Pacific earthquake zone and the continentalearthquake zone, so the earthquakes in our country are of high frequency and of highintensity, The earthquakes not only result in the structural destroys but also induce thesecond disasters, such as fire and so on, which inducing much lose. The vibrationcharacter sensor using the ground acceleration to quickly identify the earthquake isstudied in this paper. The vibration character sensor can be used by the importantengineering and the lifeline engineering. The vibration character sensor calculates thevibration characters though which the earthquake is recognized. The vibrationcharacter sensor can reduce the chance making false alarm and offer the earthquakerescue work guidance.The key work of this paper is studying the vibration character sensor andchoosing the calculation methods, such as the processing of the crude signal, and thevibration character. Then the methods identifying soil liquefaction through theearthquake acceleration time history record are studied.The processing of crude signals: the crude signals must be processed to removethe baseline drifts and to be filtered before used. Several methods are discussed, thehigh passing Butterworth filter can be used for real time signal processing, and theleast square error method can be used when real time signal processing is notrequired.Vibration character: 261 earthquake vertical records are used to identify the Pphase of the earthquake using the statistical method. And the 3 seconds records afterthe P phase arrival are analyzed to find some vibration characters, such as spectrum,ground velocity, zero crossing time. 489 records other than earthquake records and1642 earthquake horizontal records are analyzed to fmd some vibration characterssuch as spectrum and zero crossing time to identifying the earthquake from others.Soil liquefaction identifying: several methods identifying the soil liquefactionare discussed. This article chooses the wavelet transform and the Hilbert spectrumtransform to get the ground instantaneous frequency through which the soilliquefaction is identifying.In the end, the sketch map of the vibration character sensor which analyzes thewhole record and the functions of all the parts are theoretically constructed.