Electronic Vision System for Coffee Bean Defect Classification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional coffee bean classification methods fail to effectively remove beans mildly affected by the Coffee berry borer and those with defective endosperm during wet processing, leading to quality issues and economic losses for coffee growers.

Innovation Solution

A device featuring a feeding mechanism, an electronic bean vision system, and a pneumatic ejection mechanism that captures digital images of washed coffee beans, analyzes their RGB components, and uses thresholding and vector analysis to identify defective beans, such as CBB-affected, black, unripe, fermented, and mechanically damaged beans, and ejects them from the main flow using high-intensity LEDs and CCD cameras.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional classification methods are used, then the process is simple and equipment is basic, but defective beans including CBB-affected beans cannot be effectively removed

Engineering Contradiction:
Improvedefective bean removal effectivenessVSAvoidclassification system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical classification methods with an electronic vision system that uses digital image analysis, color space transformation (RGB to HSV), and computer algorithms to identify and classify defective beans. This substitution enables detection of CBB-affected beans and other defects that mechanical methods cannot distinguish, significantly improving removal effectiveness while introducing electronic and software components that increase system complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the classification problem by changing the parameter space from simple visual inspection to multi-dimensional color analysis using HSV color space (Hue, Saturation, Value). By analyzing color parameters and creating histograms of these parameters, the system can distinguish defective beans based on subtle color variations that are not apparent in traditional classification, thereby improving detection reliability

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If digital image analysis is used to identify defective beans, then identification effectiveness increases to 90%, but the device complexity and processing requirements increase

Engineering Contradiction:
Improvedefective bean identification accuracyVSAvoidvision system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces subjective visual inspection with objective digital image analysis using CCD cameras and computer vision algorithms. The system captures digital images, converts RGB values to HSV color space, and uses histogram analysis to automatically identify defective beans with 90% accuracy. This substitution of mechanical/optical inspection with electronic analysis achieves superior measurement precision while requiring sophisticated image processing equipment and software

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a digital copy of the bean's visual properties through image capture and color space transformation. By analyzing the HSV parameters of this digital representation rather than the physical bean itself, the system achieves precise identification of defects while separating the analysis process from the physical object, thereby improving measurement precision through computational analysis

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If washed coffee beans with water film are processed, then the beans are cleaner, but traditional classification machines designed for dry materials cannot effectively classify them

Engineering Contradiction:
Improvemachine adaptability to wet materialVSAvoidclassification effectiveness for wet beans
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent designs a classification system that is universal to both dry and wet coffee beans. The electronic vision system and pneumatic ejection mechanism can handle beans in different moisture states, making the device adaptable to various processing stages. The system's reliability for wet beans is improved by using non-contact optical detection and pneumatic ejection that work effectively with the water film present on washed beans

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses a pneumatic ejection system to remove defective beans from the wet stream. Compressed air jets are directed at identified defective beans to blow them off the conveyor belt into a separate collection area. This pneumatic mechanism is particularly suited for wet beans as it avoids mechanical contact that could spread moisture or cause clumping, thereby improving classification effectiveness for wet material while maintaining adaptability

Inventive Principle:
Principle #29Pneumatics and hydraulics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device achieves a high identification effectiveness of 90% for defective beans, enabling coffee growers to produce higher-quality coffee and increase income by ensuring only high-quality beans are processed, thereby providing better raw material to exporters.

Implementation Method 1

a pneumatic ejection mechanism that engages to eject the defective beans from the main flow

Methodology Applied
Scientific EffectPneumatic ejection: Jet

Implementation Method 2

an electronic bean vision system... that captures digital images of washed coffee beans, analyzes their RGB components

Methodology Applied
Scientific EffectLight reflection and color analysis: Reflection

Data Source

PatentUS11077468B2Device and method for classifying seeds
Publication Date: 2021.08.03 FEDERACION NACIONAL DE CAFETEROS DE COLOMBIA
  • US11077468B2 patent drawing
  • US11077468B2 patent drawing
  • US11077468B2 patent drawing

AI summary

The present invention relates to a device and method for classifying seeds, for example coffee seeds. The device is characterised by: a seed-feeding mechanism; a seed-containing mechanism connected to the seed-feeding mechanism; an electronic seed-viewing system operationally disposed in the seed-containing mechanism; a seed-ejecting mechanism connected to the outlet of the seed-containing mechanism, the electronic seed-viewing system having a central processing unit that implements methods for classifying seeds. The method is characterised by the steps of: a) obtaining a digital image of the seed; b) storing the RGB components of the image obtained in step a); c) generating a histogram for each colorimetric and luminosity component of the histogram of step b); d) determining the thresholding point according to Otsu's method; e) obtaining a binary image; f) removing areas; g) obtaining the edges; h) obtaining the vectors corresponding to the seeds; i) identifying black seeds; j) identifying seeds with fermentation- and immaturity-related defects; k) identifying seeds with mechanical damage; and l) actuating a seed-ejecting mechanism, activating actuators for black seeds, actuators for seeds with fermentation- and immaturity-related defects and actuators for seeds with mechanical damage.