Sound pattern discrimination system
First Claim
1. A sound discrimination and control system including in combination:
- a first omni-directional sound pickup means;
trigger circuit means for producing a substantially square wave signal at the output thereof in response to an analog signal unit;
first band-pass amplifier circuit means coupled between said first sound pickup means and the input of said trigger circuit means for supplying analog signals in a predetermined frequency band to said trigger circuit means from said sound pickup means;
second and third directional sound pickup means responsive to sounds from different directions;
first and second analog-to-digital converter means for producing a digital signal on the outputs thereof corresponding to the amplitude of analog signals on the inputs thereof;
second band-pass amplifier circuit means coupled between said second sound pickup means and the input of said first analog-to-digital converter means;
third band-pass amplifier circuit means coupled between said third sound pickup means and said second analog-to-digital converter means;
counter means coupled with the output of said trigger circuit means;
timer means coupled with said counter means for enabling operation of said counter means for predetermined time intervals;
pattern recognition comparator means coupled with said counter means for producing output signals indicative of recognition of a predetermined sound pattern;
control means coupled with the outputs of said first and second analog-to-digital signal converters for providing an output indicative of the relative magnitude of the amplitude of signals provided thereto; and
means coupled with said sound pattern recognition means and said control means for providing an output signal indicative of the presence of a predetermined sound pattern and of the direction of such predetermined sound pattern.
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Accused Products
Abstract
A system is provided for the detection and recognition of pre-established sound patterns such as the various patterns produced by the sirens of emergency vehicles. The system includes a microprocessor which programmed with pre-established sequence detection algorithms corresponding to the different types of emergency vehicles sirens signal patterns which are to be recognized. A first omnidirectional microphone is coupled through a bandpass circuit to a trigger circuit to produce square wave signals representative of analog signals in the band of interest. At least two directional microphones are coupled through similar bandpass amplifier circuits to analog digital converters which produce a digital output representative of the strength of the signals received by the directional microphones. This directional information along with the output of the Schmitt trigger is supplied to the microprocessor which is used to control the signal lights at an intersection in response to the detected siren.
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Citations
18 Claims
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1. A sound discrimination and control system including in combination:
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a first omni-directional sound pickup means; trigger circuit means for producing a substantially square wave signal at the output thereof in response to an analog signal unit; first band-pass amplifier circuit means coupled between said first sound pickup means and the input of said trigger circuit means for supplying analog signals in a predetermined frequency band to said trigger circuit means from said sound pickup means; second and third directional sound pickup means responsive to sounds from different directions; first and second analog-to-digital converter means for producing a digital signal on the outputs thereof corresponding to the amplitude of analog signals on the inputs thereof; second band-pass amplifier circuit means coupled between said second sound pickup means and the input of said first analog-to-digital converter means; third band-pass amplifier circuit means coupled between said third sound pickup means and said second analog-to-digital converter means; counter means coupled with the output of said trigger circuit means; timer means coupled with said counter means for enabling operation of said counter means for predetermined time intervals; pattern recognition comparator means coupled with said counter means for producing output signals indicative of recognition of a predetermined sound pattern; control means coupled with the outputs of said first and second analog-to-digital signal converters for providing an output indicative of the relative magnitude of the amplitude of signals provided thereto; and means coupled with said sound pattern recognition means and said control means for providing an output signal indicative of the presence of a predetermined sound pattern and of the direction of such predetermined sound pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification