Method of transfer function generation and active noise cancellation in a vibrating system
US4947435A · kind A · utility
Inventor
Key dates
| Filing date | Mar 25, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Mar 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2210/3045
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A method for the active cancellation of an incident vibration field (N(i.omega.)) wherein a cancelling vibration field (C(i.omega.)) is superposed on the incident field to create a residual vibration field (R(i.omega.)). The residual field is operated on with a transfer function to obtain an updated cancelling field, the transfer function being divided by a reference point (10) into an upstream part (Fi(i.omega.)) and a downstream part (Fo(i.omega.)). The downstream part (Fo(i.omega.)) of the transfer function is periodically updated by multiplying the last obtained value (Fo.sub.n (i.omega.) by a factor which is the ratio of a computational value of the last cancelling field (C.sub.n (i.omega.)) and a computational value for the sum of previous residual fields (R(i.omega.)).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.