Active vibration or noise suppression system

An active vibration or noise suppression system for actively suppressing vibration or noise at an evaluation point by outputting control vibration or control sound, wherein:

• the active vibration or noise suppression system comprises:
• a control signal generating unit for generating a sine wave control signal y(n) constituted by frequency of a vibration or noise source, and an amplitude filter coefficient and a phase filter coefficient as an adaptive filter coefficient;
• a control vibration or control sound generator for outputting the control vibration or control sound corresponding to the sine wave control signal y(n);
• a residual error signal detecting unit for detecting, at the evaluation point, a residual error signal e(n) generated by interference between vibration or noise caused by the vibration or noise source and the control vibration or control sound;
• an amplitude filter coefficient updating unit for calculating an amplitude update term Δa(n+1) to be added to or subtracted from a last updated value of the amplitude filter coefficient a(n) for update, so as to reduce the residual error signal e(n);
• and
• a phase filter coefficient updating unit for calculating a phase update term Δφ(n+1) to be added to or subtracted from a last updated value of the phase filter coefficient φ(n) for update, so as to reduce the residual error signal e(n),
• the sine wave control signal y(n) is expressed by a sine wave having an amplitude component and a phase component,
• each of the amplitude update term Δa(n+1) and the phase update term Δφ(n+1) contains a sine wave or cosine wave term having an amplitude component and a phase component, and
• the phase component of the sine wave control signal y(n) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ(n), or the phase component of the sine wave or cosine wave term of each of the amplitude update term Δa(n+1) and the phase update term Δφ(n+1) is expressed by multiplying a coefficient other than 1 by the phase filter coefficient φ(n).