Patent · US Expired

Monitoring apparatus and control apparatus for traffic signal lights

US6184799A · kind A · utility

4Cited by
9References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 17, 1996
Grant dateFeb 6, 2001
Priority date
Expiry dateDec 17, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08G1/097
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

Monitoring and control apparatus for fail-safe monitoring for normal operation of traffic signal lights provided at an intersection or the like where a plurality of roads intersect. The illumination conditions of respective signal lights are detected using as sensor device, and when the number of illuminated or non-illuminated signal lights is a predetermined number, a normal judgment output of logic value 1 corresponding to a high energy condition is generated while, when the number of illuminated or non-illuminated signal lights is not the predetermined number, an abnormal judgment output of logic value 0 corresponding to a low energy condition is generated. As a result, when a fault in the monitoring apparatus stops the output, the resultant output condition is the same as for a danger condition due to a signal light abnormality, resulting in an extremely safe signal light monitoring and control with excellent fail-safe characteristics.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.