| 摘要 |
PURPOSE: To reduce the calculation volume in filter processing by converting the frequency transfer function between an actuator means and a sensor means so that the condition of control stability/instability is not dependent upon the frequency of oscillation and updating the amplitude component of Fourier series of each harmonic component. CONSTITUTION: When a control variable (u) to cancel the noise is generated from a speaker, the variable (u) is recognized as convolved with the impulse response function between the speaker and a microphone by the microphone and is detected as a residual noise error signal (e). This error signal (e) is inputted to a controller to calculate the control variable (u). It is considered that the engine noise is dependent upon the rotational frequency of the engine, and an ignition signal is inputted and is recognized as a periodω, and a control coefficient (f) is used to determine the output (u) to the speaker. At this time, the transfer characteristic function between the speaker and the microphone is preliminarily determined with respect to a convergence coefficientα, and this transfer function is converted to determine the control coefficient (f).
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