Multi frequency photoelectric detection system
US6377167B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2001 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | May 1, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S2013/9315
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Collision avoidance apparatus (28, 30) is mounted on a host vehicle (20) to detect the presence of an adjacent vehicle (22) within a monitored zone (24, 26). A sensor module (30) includes a plurality of discrete sensor systems for monitoring unique portions of the monitored zone (24, 26), each of which comprises an emitter (52) emitting a fixed frequency modulated beam (58) of light energy (54) with a predetermined burst length into its unique portion of the monitored zone (24, 26), and a receiver (68) having a field of view (62), substantially aligned with emitted beam (58) to produce a fixed optical overlap area (A), and for sensing light energy (66) and generating a received signal. A frequency generator (48) produces two or more predetermined different fixed frequencies for use by the emitter (52) to emit beams (58) at each frequency. A phase shifter (70) produces a phase shifted reference signal with a different predetermined phase delay relationship to each fixed frequency. A mixer (72) mixes each received signal and each phase shifted reference signal to produce demodulation signals from for each frequency. A processor (40) receives and processes accoupled logic level detect…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.