Patent ID: 9539616
Date: 2017-01-10
CPC Classifications: B06B,G01H

Claim:
1. An infrasound generating device based on a displacement-feedback type vibration exciter comprising: a displacement-feedback type vibration exciter system, an infrasound generating chamber and a laser vibrometer measuring the vibration displacement of the displacement-feedback type vibration exciter, wherein standard infrasonic pressure generated in the infrasound generating chamber is calculated through vibration displacement measured by the laser vibrometer: where p is sound pressure; y is specific heat ratio of the air; P 0 is static pressure; d is diameter of a piston; x is displacement of the piston; V 0 is volume of the airtight chamber when the piston is at its equilibrium position; the displacement-feedback type vibration exciter system comprising a signal generator, a power amplifier, a vibration exciter and a displacement-feedback component; the displacement-feedback component comprising a displacement sensor measuring the displacement of a moving part of the displacement-feedback type vibration exciter, a comparator comparing a displacement signal with a standard signal produced by the signal generator to obtain the deviation between the standard signal and the displacement signal and a controller processing a deviation signal, a signal conditioning circuit being adopted between the displacement sensor and the comparator to process the displacement signal; the moving part of the displacement-feedback type vibration exciter being driven by the controller and the power amplifier being adopted between the controller and the displacement-feedback type vibration exciter to amplify an output control signal of the controller; the vibration exciter being equipped with an optical channel allowing a measurement beam of the laser vibrometer to travel through and a reflector reflecting the measurement beam back to the laser vibrometer, the measurement beam injecting into the vibration exciter from the exciter end and the reflector being attached to a back end of the moving part of the vibration exciter; and the infrasound generating chamber being airtight and the piston operatively fitting in the chamber, the piston being tightly connected with a front end of the moving part of the vibration exciter and an infrasonic sensor to be calibrated being installed inside the infrasound generating chamber.