ELECTRET-TYPE VIBRATION DETECTION SYSTEM, METHOD FOR GENERATING EXTERNAL VIBRATION INFORMATION, METHOD FOR GENERATING TRANSFER FUNCTION INFORMATION RELATING TO EXTERNAL VIBRATION, PROGRAM FOR GENERATING EXTERNAL VIBRATION INFORMATION, AND PROGRAM FOR GENERATING TRANSFER FUNCTION INFORMATION RELATING TO EXTERNAL VIBRATION

摘要

Transition information relating to an output power voltage in a predetermined time period is obtained from a vibration-powered generator that performs vibration-induced power generation by relatively displacing on the basis of external vibration an electret group and an electrode group. A Fourier transform for the transition information relating to the output power voltage is performed to compute output spectrum information relating to the output power voltage. Moreover, vibration velocity information relating to the external vibration within the predetermined period is created for the computed output spectrum information, by taking into account transfer function information that defines a correlation between the vibration velocity of the external vibration of the predetermined frequency range included in the external vibration and the output power voltage of the vibration-powered generator, with this transfer function information containing a transfer coefficient set corresponding to on each of a plurality of frequencies belonging to the predetermined frequency range to place the vibration velocity of the external vibration and the output power voltage of the vibration-powered generator in a predetermined proportional relationship. As a result, it is possible to easily and accurately detect external vibration information using electrets.