Control signal coding and detection in the audible and inaudible ranges
First Claim
1. A method of pre-emptively controlling a traffic signal, comprising the steps of:
- producing an audible siren sound using a transducer;
using same said transducer, producing an acoustic coded signal including a regularly recurring digital codeword signifying a selected one of a plurality of traffic signal commands;
detecting the codeword and determining the traffic signal command; and
controlling the traffic signal in accordance with the traffic signal command.
3 Assignments
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Accused Products
Abstract
A coded siren sound generator and a corresponding detector module are provided which allow uniquely coded tone patterns generated by the coded siren to be detected and processed such that only specific sirens will activate the detector module. In one embodiment, only a few codewords are sent by the transmitter. The receiver looks for the occurrence of one or more of these selected codewords and takes a predetermined action based on programming of the detector. The system may operate at audible or ultrasonic frequencies. In accordance with a further embodiment, audio (either audible or ultrasonic) "packets" are sent by the transmitter These packets contain sufficient information to uniquely identify the vehicle sending the packet and allow the vehicle to send commands and data to the detector. The commands and data may be for purposes such as requesting emergency pre-emption for a left turn at an intersection, requesting straight ahead pre-emption, etc.
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Citations
10 Claims
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1. A method of pre-emptively controlling a traffic signal, comprising the steps of:
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producing an audible siren sound using a transducer; using same said transducer, producing an acoustic coded signal including a regularly recurring digital codeword signifying a selected one of a plurality of traffic signal commands; detecting the codeword and determining the traffic signal command; and
controlling the traffic signal in accordance with the traffic signal command. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of pre-emptively controlling a traffic signal, comprising the steps of:
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producing an audible siren sound using a transducer; using same said transducer, producing an acoustic coded signal including a regularly recurring digital codeword signifying a selected one of a plurality of traffic signal commands; detecting the codeword; determining whether the codeword is valid; determining the traffic signal command; and if the codeword is valid, controlling the traffic signal in accordance with the traffic signal command. - View Dependent Claims (8, 9, 10)
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Specification