FEATURE ABSTRACTOR

• US 3,568,075 A
• Filed: 01/03/1969
• Issued: 03/02/1971
• Est. Priority Date: 01/03/1969
• Status: Expired due to Term

• Current Assignee: George J. Dusheck Jr, Phillips B. Scott, Thomas P. Kelley
• Original Assignee: George J. Dusheck Jr, Phillips B. Scott, Thomas P. Kelley
• Inventors: Dusheck, George J. Jr., Kelley, Thomas P., Scott, Phillips B.
• Application Number:
  US04/788,809
• Time in Patent Office: 788 Days
• US Class Current: 327/96
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17

Abstract

A feature abstractor producing an output signal indicative of the amplitude slope of sequentially sampled amplitude-timefrequency domain signals. This is obtained by taking the differences between successive pulses and applying such differences to the inputs of neuron gates. The neuron gates detect when two successive pulses are of the same polarity and provide an output indicative of the lesser of the two successive pulses.

Claims

1. A NETWORK RECEIVING SEQUENTIALLY SAMPLED AMPLITUDE-TIMEFREQUENCY DOMAIN SIGNALS FOR ABSTRACTING PRIMARY FEATURES THEREFROM COMPRISING:

FIRST MEANS RECEIVING THE SEQUENTIALLY SAMPLED SIGNALS FOR DETECTING THE POSITIVE AMPLITUDE DIFFERENCE BETWEEN SUCCESSIVE SIGNALS AND PROVIDING OUTPUT PULSES OF AMPLITUDE INDICATIVE THEREOF;

AND SECOND MEANS RECEIVING SAID OUTPUT PULSES AND PASSING THE LOWER AMPLITUDE PULSE OF TWO SUCCESSIVE PULSES OF THE SAME POLARITY.

2. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 1 wherein said first means comprises:

first and second switch means for alternatively passing said amplitude-time-frequency domain signals in response to control timing signals;

first and second holding means one each respectively connected to said first and second switch means for alternatively holding the signals passed by said first and second switch means; and

first and second differential amplifier means one each respectively operatively connected to said first and said second holding means for passing the positive amplitude difference between successively received signals from said first and second holding means.

3. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 2 wherein:

said first and said second differential amplifier means each has a positive and a negative input terminal;

said first holding means is connected both to the positive terminal of said first differential amplifier means and the negative terminal of said second differential amplifier means for providing signals thereto; and

said second holding means is connected both to the negative terminal of said first differential amplifier means and the positive terminals of said second differential amplifier means for providing signals thereto.

4. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 3 wherein:

said first and said second differential amplifier means provide difference signals representative of positive differences between the signals supplied thereto by said first and said second holding means.

5. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 4 wherein said second means comprises:

first and second switch pairs, one switch of each switch pair being connected to the output of said first differential amplifier means and the other switch of each switch pair being connected to the output of said second differential amplifier means.

6. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 5 wherein:

said first switch pair is closed responsive to control timing signals when said second switch pair Is open; and

said first switch pair is open when said first switch means is closed and said second switch pair is opened when said second switch means is closed for passing said positive difference signals.

7. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 7 wherein said second means further comprises:

a plurality of holding means open each connected to each switch of said pairs of switches for holding said positive difference signals for preselected time periods;

a first abstractor means operatively connected to one switch of each of said switch pairs through a first portion of said plurality of holding means for passing the lower amplitude pulse of two received successive difference signals of the same polarity; and

a second abstractor means operatively connected to the other one switch of each of said switch pairs through a second portion of said plurality of holding means for passing the lower amplitude pulse of two received successive difference signals of the same polarity.

8. A network receiving sequentially sampled amplitude-time-frequency domain signals for abstracting primary features therefrom according to claim 7 wherein each of said abstractor means comprises:

a first neuron having a first excitatory input, a first inhibitory input, and an output;

a second neuron having a second excitatory input, a second inhibitory input, and an output;

said first excitatory and inhibitory inputs connected to receive said positive difference signals;

said second excitatory input connected to said first excitatory input to receive a selected one of said positive difference signals;

said second inhibitory input connected to said first neuron output to receive an output signal therefrom indicative of the minimum positive difference between the positive difference signals received by said first neuron; and

said second neuron providing at the output thereof said primary features by abstracting the minimum positive difference between said selected positive difference signal on said second excitatory input and the signal on said second inhibitory input.