EP 0748494 B1 19980617 - SIREN DETECTOR
Title (en)
SIREN DETECTOR
Title (de)
SIRENENDETEKTOR
Title (fr)
DETECTEUR DE SIRENE
Publication
Application
Priority
CA 9400119 W 19940304
Abstract (en)
[origin: WO9524028A1] An improved siren detector for detecting siren sounds which precess at known warble rates, such as yelp, wail, and high-low, within a selected frequency band. A transducer detects the siren sounds and produces a corresponding electrical output signal. This electrical output signal is filtered to reject signals outside of the selected siren frequency band. The signal is processed to determine the amplitude of the electrical signal, and hence the sound level of the siren sound at the transducer input. This signal is also processed by an amplitude limiter and frequency discriminator to determine the instantaneous frequency of the siren sound. This discriminator is followed by a non-linear filter to remove the FM clicks characteristic of siren sounds having a low signal to noise ratio. Selection filters are used to analyze the precession rates, maximum frequency, minimum frequency, and shape of the precession characteristic to classify the siren as to its type, such as yelp, wail, and high-low. A sound which meets the selection criteria and has a sound level above a predetermined threshold causes the siren detector to trigger signal which drives a preempt output. This preempt output signal is input to a traffic light control system. This alerts the traffic light control system to control the Pedestrian Walk/Don't Walk and traffic lights to cause pedestrians to clear the intersection and to provide a preemptive traffic control signal to a vehicle eqquipped with the appropriate siren.
IPC 1-7
IPC 8 full level
G01H 3/06 (2006.01); G08G 1/087 (2006.01); G10L 15/00 (2013.01); G10L 15/10 (2006.01); G10L 15/20 (2006.01); G10L 17/26 (2013.01); G10L 21/0208 (2013.01)
IPC 8 main group level
G08G (2006.01)
CPC (source: EP)
G08G 1/087 (2013.01)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
WO 9524028 A1 19950908; AU 6152694 A 19950918; AU 681380 B2 19970828; CA 2183868 A1 19950908; CA 2183868 C 20020115; DE 69411195 D1 19980723; DE 69411195 T2 19990204; EP 0748494 A1 19961218; EP 0748494 B1 19980617; HK 1009352 A1 19990528; JP H09512902 A 19971222; NZ 262083 A 19980527
DOCDB simple family (application)
CA 9400119 W 19940304; AU 6152694 A 19940304; CA 2183868 A 19940304; DE 69411195 T 19940304; EP 94908234 A 19940304; HK 98109887 A 19980813; JP 52258395 A 19940304; NZ 26208394 A 19940304