Self-powered vehicle detection system
US4302746A · kind A · utility
21Cited by
4References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1980 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Feb 1, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/042
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An improved self-powered vehicle detector (SPVD) uses a two-axis magnetomr to sense a vehicle's magnetic signature and then telemeter vehicle presence information to a roadside receiver. The SPVD system includes digital nulling loops to cancel D.C. offset changes in the magnetometic output, a multi-tone code transmitter to transmit vehicle presence and SPVD condition signal, and an omnidirectional microstrip antenna to simplify installation and maintenance of the SPVD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.