Automatic optical inspection and sorting

• US 4,244,650 A
• Filed: 04/20/1978
• Issued: 01/13/1981
• Est. Priority Date: 04/20/1978
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Garfunkel, James H., Koeneman, Kenneth P.
• Primary Examiner(s): Clark, Conrad J.
• Assistant Examiner(s): Punter, Wm. H.
• Application Number:
  US05/898,221
• Time in Patent Office: 999 Days
• Field of Search: 356/71, 356/446, 356/448, 356/394, 250/223 B, 250/255, 250/257, 250/202, 340/146.3 Q, 340/146.3 AC
• US Class Current: 356/71
• CPC Class Codes: B07C 5/126 by means of photo-electric sensors, e.g. according to colour sorting according to optical properties B07C5/342; material testing with the aid of optical means G01N21/00
• CPC Class Codes: G01N 2033/0081 containers; packages; bottles

Abstract

In this disclosure is described apparatus for automatic pattern or object recognition in which objects or goods with optically recognizable patterns are optically scanned for the pattern by passing the objects in front of optical sensor means where the light reflected from the object is received by the sensor means. In this disclosure there is described in detail apparatus for identifying and sorting various types of returnable bottles such as soft drink bottles by scanning across the bottles, the light reflected from the bottle graphics providing a coded signal or signature representing the bottle type. The identification is accomplished by considering such signature features as number of peaks, largest gap, area under curve, summation of difference between consecutive data points and the ratio of the area to the difference summation. The values obtained for the features are then matched with known feature bounds to provide the identification.

Claims

1. Pattern recognition apparatus comprising:

optical sensor means detecting reflected light from the surface of goods having a pattern to be identified, the sensor means scanning a line across the goods as the goods pass in front of the sensor means, the light reflected from the pattern of the passing goods providing an analog signal pattern output from said sensing means which analog signal pattern is characteristic of the pattern sensed;

means for sampling the analog signal pattern at predetermined increments of movement of the goods and means converting each said signal sample to a digital bit;

means for temporarily storing the digital bits representing the signal pattern from said goods, said temporarily stored digital signal containing information which can be expressed as signal peaks, area under the curve of the digital signal, gap in the signal, and vertical excursions of the digital signal from one bit to the next;

means for counting the number of peaks of the digital signal;

means for determining the area under the curve of the digital signal;

means for determining the largest gap in the digital signal, where gap is defined as the number of consecutive data points at a signal level of less than a predetermined digital number;

means for summing the total of the positive and negative vertical excursions of the digital signal, the sum being referred to as sigma;

means for dividing the area value by the sigma value to obtain a value Y; and

,

means for comparing the number of peaks, the area, the largest gap, and the value Y with prestored information characteristic of each pattern type to be recognized.

2. Bottle identifying apparatus comprising:

means for rotating a bottle to be identified;

optical sensor means detecting reflected light from the surface of a bottle to be identified, the sensor means scanning a line across the graphics of the bottle as the bottle rotates in front of the sensor means, the light reflected from the rotating bottle graphics during a rotation of the bottle providing an analog signal pattern output from said sensing means which analog signal pattern is characteristic of that bottle type;

means for sampling the analog signal pattern at angular increments of 360°

/x during the rotation of the bottle and means converting each signal sample to a digital bit where x is an integer;

means for temporarily storing the x digital bits representing the signal pattern from a rotation of said bottle, said temporarily stored digital signal containing information which can be expressed as signal peaks, area under the curve of the data points of the signal, gap in the signal, and vertical excursions of the digital signal from one bit to the next;

means for counting the number of peaks of the digital signal;

means for determining the area under the curve of the digital signal;

means for determining the largest gap in the digital signal, where gap is defined as the number of consecutive data points at a signal level of less than a predetermined digital number;

means for summing the total of the positive and negative vertical excursions of the digital signal, the sum being referred to as sigma;

means for dividing the area value by the sigma value to obtain a value Y; and

,

means for comparing the number of peaks, the area, the largest gap, and the value Y with prestored information characteristic of each bottle type to be recognized.

3. Bottle identifying apparatus, comprising:

first and second optical sensor means;

means for rotating a bottle to be identified, said first and second optical sensor means each being mounted in proximity to the rotating bottle and each illuminating an area of and receiving reflective light from bottle graphics in the illuminated area of the rotating bottle, the sensor means each providing an analog electrical output signal proportional to the reflected light from the bottle surface as the bottle rotates;

shaft encoder means connected to said bottle rotating means, said shaft encoder means providing a predetermined number of output electrical pulses during a rotation of the bottle;

means including switching means actuated in response to the shaft encoder pulses and selectively connecting said first and second sensor means output sigma to analog-to-digital converter means at each occurrence of said shaft encoder means;

analog-to-digital converter means actuated in response to the shaft encoder pulses having an input circuit adapted to be connected to receive said analog signals and to convert said signals to a digital form;

means connecting said shaft encoder output pulses to said converter means to initiate the analog-to-digital conversion at the occurrence of each said pulse;

permanent storage means for storing digital information characteristic of each bottle type to be recognized;

memory means for temporarily storing the digital bits representing the two signal patterns from a rotation of said bottle, said temporarily stored digital signals containing information which can be expressed as signal peaks, area under the curve of the digital signal, gap in the signal, and vertical excursions of the digital signal from one bit to the next;

means for determining the area under the curve of the digital signal;

means for counting the number of peaks of the digital signal;

means for determining the largest gap in the digital signal, where gap is defined as the number of consecutive data points at a signal level of less than a predetermined digital number;

means for summing the total of the positive and negative vertical excursions of the digital signal, the sum being referred to as sigma;

means for dividing the area value by the signal value to obtain a value Y; and

,

means for comparing said number of peaks, said area under the curve, said largest gap, and the value Y with prestored information as to peaks, area, gap and Y characteristic of each bottle type to be recognized.

4. The apparatus of claim 3 wherein said means for comparing further comprises means for checking the digital signal outputs of the two sensors for the area under the curve of each and for selecting the signal of larger area for further analysis.