The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 1996
Filed:
Mar. 18, 1994
Hiroshi Uchida, Hiroshima-ken, JP;
Tetsuro Butsuen, Hiroshima-ken, JP;
Norihiko Nakao, Hiroshima-ken, JP;
Mazda Motor Corporation, Hiroshima-ken, JP;
Abstract
Periodic first vibrations generated from the engine are reduced by the interference with the second vibrations generated from the speakers disposed in the vehicle compartment of the vehicle. The second vibrations are set in a cycle unit of the first vibrations, and they are corrected (optimized) on the basis of the signals from the microphones detecting the vibrations within the vehicle compartment and the transmission characteristic between the microphones and the speakers. During a transient period of time during which the cycles vary (during which the data lengths of the data of the second vibrations vary), such as by acceleration or deceleration, the data on the vibration wave form of the previous vibrations is corrected in anticipation (i.e. the data length is corrected), the current vibration wave form is set. The correction of the data length is made by inserting a given number of estimated data values into the previous data length or by deleting a given number of the data values from the previous data length. Further, the data length can be corrected by extending or contracting the previous vibration wave form as a whole so as to provide the data length in accordance with the current vibration wave form.