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:
Feb. 25, 1992
Filed:
Feb. 13, 1990
Steven A Tretter, Silver Spring, MD (US);
University of Maryland at College Park, College Park, MD (US);
Abstract
Repetitive phenomena cancelling controller arrangement for cancelling unwanted repetitive phenomena comprising known fundamental frequencies. The known frequencies are determined and an electrical known frequency signal corresponding to the known fundamental frequencies of the unwanted repetition phenomena is generated. A plurality of sensors are employed in which each sensor senses residual phenomena and generates an electrical residual phenomena signal representative of the residual phenomena. A plurality of actuators are provided for cancelling phenomena signals at a plurality of locations, and a controller is utilized for automatically controlling each of the actuators as a predetermined function of the known fundamental frequencies of the unwanted repetitive phenomena and of the residual phenomena signals from the plurality of sensors. In this arrangement the plurality of actuators operate to selectively cancel discrete harmonics of the known fundamental frequencies while accommodating interactions between the various sensors and actuators.