Holographic object position and type sensing system and method
US6356854B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1999 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Apr 5, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/0066
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Systems and methods for determining the position and classification of an object and which may provide signals that control deployment of an active restraint device, for example. Using a pulsed laser light beam from a laser source that is spread and preferably diffused to avoid ocular damage, an interference pattern is returned to a sensing module through a spectral filter. There it is optionally combined with a reference beam from the laser source, modified to emulate coherence length effects, and incident upon a phase transmission holographic template that may be segmented into regions for example. Each region of the holographic template contains Fourier transform images of occupant types. Behind the holographic template is a detector array that is sensitive to the laser light. An interference pattern derived from the object is convoluted or cross-correlated with the template. When an match occurs, a bright spot appears on the detector array. The location of this spot within the region contains position information. The relative brightness and location of spots within each region provide information relative to their classification. Using fuzzy logic, neural networks, or an algeb…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.