Acoustic and video imaging system for quality determination of agricultural products

• US 5,309,374 A
• Filed: 08/03/1992
• Issued: 05/03/1994
• Est. Priority Date: 08/03/1992
• Status: Expired due to Term

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Inventors: Misra, Manjit K., Shyy, Yuh-Yuan
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US07/924,195
• Time in Patent Office: 638 Days
• Field of Search: 356/407, 364/552, 382/1, 382/8
• US Class Current: 702/81
• CPC Class Codes: B07C 5/34 Sorting according to other particular properties material testing per se G01N; quality control G07C3/14
• CPC Class Codes: G01N 15/01 specially adapted for biological cells, e.g. blood cells investigating sedimentation of particle suspensions in blood G01N15/05
• CPC Class Codes: G01N 15/0227 using imaging; using holography
• CPC Class Codes: G01N 15/10 Investigating individual particles
• CPC Class Codes: G01N 15/1433 using image recognition
• CPC Class Codes: G01N 15/1475 using image analysis for extracting features of the particle
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties
• CPC Class Codes: G01N 2015/0065 biological, e.g. blood
• CPC Class Codes: G01N 2015/0288 Sorting the particles
• CPC Class Codes: G01N 2015/0294 Particle shape
• CPC Class Codes: G01N 2015/149 Sorting the particles
• CPC Class Codes: G01N 2015/1497 Particle shape
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 33/025 Fruits or vegetables
• CPC Class Codes: G06T 2207/30128 Food products
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/13 Edge detection

Abstract

A flexible system for determining the quality of agricultural products based on characteristics such as, for example, mass, shape, hardness, size, color and surface texture is disclosed herein. The quality determination apparatus includes a feeder assembly for sequentially dropping individual product samples upon an impact transducer arrangement. The impact transducer generates transducer signals indicative of the physical characteristics of each product sample. In addition, an imaging device operates to synthesize a digital image representation of each product sample. The transducer signal and digital image representation corresponding to each product are analyzed so as to determine the appropriate degree of quality to be associated therewith.

Claims

1. An apparatus for determining quality of an agricultural product, comprising:

acoustical transducer means for generating a transducer signal indicative of a set of physical characteristics of said product;

imaging means for synthesizing a digital image representation of said product; and

signal processing means for analyzing said transducer signal and said digital image representation;

whereby, based on said analysis, a degree of quality is associated with said agricultural product.

2. The apparatus of claim 1 wherein said acoustical transducer means further includes a drop tube feeder apparatus for dropping said agricultural product upon said transducer.

3. The apparatus of claim 2 wherein said imaging means includes camera means for providing an image of said agricultural product and for digitizing said image so as to create said digital image representation.

4. The apparatus of claim 1 wherein said physical characteristics include mass and hardness.

5. The apparatus of claim 4 wherein said digital image representation includes information pertaining to shape and boundary roughness of said agricultural product.

6. The apparatus of claim 5 wherein said signal processing means includes means for determining said shape of said agricultural product based on said digital image representation, said shape determining means including means for identifying a portion of said digital image representation as corresponding to an edge of said agricultural product and means for determining a center of said product relative to said edge.

7. The apparatus of claim 6 wherein said signal processing means includes means for determining roughness of said agricultural product by plotting separation between predefined sections of said edge and said center and comparing said plot with a reference plot.

8. The apparatus of claim 4 wherein said acoustical transducer means includes an impact transducer, said transducer signal being generated in response to impact of said agricultural product upon said transducer.

9. The apparatus of claim 8 wherein said signal processing means includes means for performing a time-domain analysis of said transducer signal.

10. The apparatus of claim 9 wherein said time-domain analysis means includes means for detecting a peak region of said transducer signal, wherein magnitude of said transducer signal at said peak region corresponds to said mass of said agricultural product.

11. The apparatus of claim 10 wherein a slope of said peak signal at a predefined magnitude thereof corresponds to said hardness of said agricultural product.

12. An apparatus for quality determination of beans, comprising:

acoustical transducer means for generating a transducer signal indicative of mass and hardness of said beans, said transducer means having a drop tube feeder apparatus coupled to an impact transducer;

imaging means for synthesizing a digital image representation of said product, said digital image representation including information pertaining to at least one characteristic from the set of bean characteristics consisting of shape, texture, area and color; and

signal processing means for performing a time-domain analysis upon said transducer signal and for analyzing said digital image representation;

whereby, based on said time-domain analysis and upon said analysis of said digital image representation, degrees of quality are associated with said beans.

13. A method for determining quality of an agricultural product comprising the steps of:

dropping said product upon an impact transducer, said transducer being disposed to generate a transducer signal indicative of a set of physical characteristics of said product;

creating an image of said product;

digitizing said image so as to create a digital image representation of said product;

storing said digital image representation in computer memory;

analyzing said transducer signal and digital image representation in accordance with predefined criteria;

whereby, based on said analysis, a degree of quality is associated with said agricultural product.

14. The method of claim 13 wherein said digital image representation includes information pertaining to at least one characteristic included within the set of product characteristics consisting of surface texture, area and color.

15. The method of claim 13 wherein said step of analyzing includes the step of determining said shape of said agricultural product based on said digital image representation, said shape determining step including the steps of:

identifying a portion of said digital image representation as corresponding to an edge of said agricultural product, and

determining a center of said product relative to said edge.

16. The method of claim 15 wherein said step of analyzing includes the step of determining boundary roughness of said agricultural product by plotting separation between predefined sections of said edge and said center and comparing said plot with a reference plot.

17. The method of claim 16 wherein said agricultural product comprises a bean.

18. The method of claim 13 wherein said physical characteristics include mass and hardness.

19. The method of claim 18 wherein said digital image representation includes information pertaining to shape and boundary roughness of said agricultural product.

20. The method of claim 19 wherein said step of analyzing includes the step of performing a time-domain analysis upon said transducer signal.

21. The method of claim 20 wherein said time-domain analysis step includes the step of detecting a peak region of said transducer signal, wherein magnitude of said transducer signal at said peak region corresponds to said mass of said agricultural product.

22. The method of claim 21 wherein said time-domain analysis step includes the step of determining the slope of said transducer signal at a predefined magnitude thereof wherein said slope corresponds to said hardness of said agricultural product.