Patent ID: 8471502

Claim:
A vibration damping apparatus, comprising: a reference wave production section that produces a reference wave from a fundamental frequency; a control circuit including a fundamental adaptive algorithm block that calculates fundamental order adaptive filter factors from a vibration detection signal output from a vibration detection section and the reference wave, and that produces a fundamental order vibration damping current instruction based on the fundamental order adaptive filter factors to cause vibration having an opposite phase to vibration detected by the vibration detection section; an amplitude detector that calculates a peak current value of the fundamental order vibration damping current instruction; and a fundamental order current excess detection unit that derives a fundamental order current upper limit value determined in advance from the fundamental frequency and produces, when a peak current value of the fundamental order vibration damping current instruction exceeds the fundamental order current upper limit value, a fundamental order current upper limit excess signal and outputs the produced signal to said fundamental adaptive algorithm block, wherein said fundamental adaptive algorithm block, revises, within a period within which the fundamental order current upper limit excess signal is received, the fundamental order adaptive filter factors in a direction in which the vibration damping current instruction is limited within a range determined in advance.