METHOD AND APPARATUS FOR DETECTION OF MASS OF SHOCK OBJECT

PROBLEM TO BE SOLVED: To provide a detection method, for the mass of a shock object, in which the mass is computed and processed only in the case of an acceleration signal by an actual loose part. SOLUTION: When an object having a prescribed mass in advance collides with a member which is equivalent to an inside wall, the power spectrum table of an acceleration in a prescribed response frequency width which is response- vibrated is prepared. on the basis of a response vibration within a prescribed frequency band which contains the background noise of the inside wall, a trigger level which excludes the background nose is measured. When a vibration waveform which exceeds the trigger level enters during the response vibration, a power spectrum due to the acceleration of a vibration waveform which enters in synchronization with the vibration waveform is measured in a state that the vibration waveform exceeds the trigger level for a prescribed time or more. The mass of the power spectrum table which agrees with the power spectrum is detected as the mass of the loose part.