Vibration/noise active control system for vehicles

A vibration/noise active control system for an automotive vehicle having a compartment, comprising:

• reference signal-detecting means for detecting a signal related to vibrations and noises generated within said compartment, as a reference signal;
• canceling signal-forming means having an adaptive filter, for forming a canceling signal for canceling said vibrations and noises, by means of said adaptive filter, based on said reference signal;
• converting means for converting said canceling signal formed by said canceling signal-forming means into a canceling sound;
• error-detecting means for detecting a cancellation error between said canceling sound from said converting means and said vibrations and noises within said compartment to generate an error signal;
• filter coefficient-changing means for changing a filter coefficient value of said adaptive filter, based on said error signal and said reference signal;
• memory means for storing a plurality of filter coefficient values of said adaptive filter corresponding to a plurality of predetermined traveling conditions of said vehicle, each of which is determined by at least one of traveling speed of said vehicle, a state of a road surface on which said vehicle is traveling, and a riding state of said vehicle,
• wherein said memory means comprises first memory means storing initial filter coefficient values of said adaptive filter set beforehand, in a manner corresponding to said predetermined traveling conditions, and second memory means for storing filter coefficient values of said adaptive filter changed by said filter coefficient-changing means in a manner corresponding to said predetermined traveling conditions;
• traveling condition-detecting means for detecting a traveling condition in which said vehicle is traveling;
• and
• control means for reading out a filter coefficient value of said adaptive filter corresponding to one of said predetermined traveling conditions of said vehicle to which said traveling condition detected by said traveling condition-detecting means corresponds, supplying said read-out filter coefficient value to said canceling signal-forming means to form and generate said canceling signal based on said read-out filter coefficient value, and storing said filter coefficient value of said adaptive filter changed by said filter coefficient-changing means based on said generated canceling signal,
• wherein when a change occurs in said traveling condition detected by said traveling condition-detecting means, said control means reads out from said first memory means an initial filter coefficient value corresponding to one of said predetermined traveling conditions to which said traveling condition detected by said traveling condition-detecting means immediately before occurrence of said change corresponds, reads out from said second memory means a filter coefficient value corresponding to one of said predetermined traveling conditions to which said traveling condition detected by said traveling condition-detecting means immediately after occurrence of said change corresponds, causes said canceling signal-forming means to form and generate said canceling signals based, respectively, on said initial filter coefficient value read out from said first memory means and said filter coefficient value read out from said second memory means, to execute vibration/noise control based on said generated canceling signals, and selects one of said initial filter coefficient value read out from said first memory means and said filter coefficient value read out from said second memory means, which has resulted in a smaller cancellation error, to apply same as an initial value of said adaptive filter.