Sorting Products Using Reference Element Light Compensation

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Solution Overview

Problem

Existing methods for detecting and removing inferior or strange products from a product flow are plagued by edge effects, which lead to incorrect identification due to similarities in light scattering between suitable products and reference elements, and the use of light-emitting reference elements does not adequately compensate for these edge effects.

Innovation Solution

A method involving a stream of light with a different frequency spectrum than the primary light beam is used to illuminate products, with disturbances detected to differentiate between suitable and inferior or strange products, ensuring accurate identification by only considering signals within specific detection levels that minimize edge effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a light beam is directed to products moving through a detection zone to detect inferior or strange products, then product sorting capability is achieved, but edge effects are produced in the generated signal leading to incorrect identification

Engineering Contradiction:
Improveproduct identification accuracyVSAvoidsignal measurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

A reference element is introduced as an intermediary standard object with known optical characteristics. The light beam alternates between illuminating products and the reference element, allowing the system to distinguish between signal variations caused by edge effects (which affect both equally) and those caused by actual product differences. The reference element serves as a mediator to cancel out common-mode disturbances.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the temporal parameter of illumination by alternating between product detection and reference element measurement. This time-based parameter change allows separation of edge effect signals from product characteristic signals through comparison, improving measurement precision without sacrificing identification reliability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a light-emitting reference element is used to compensate for edge effects, then some edge effect compensation is achieved, but satisfactory results are not obtained due to insufficient compensation

Engineering Contradiction:
Improveedge effect compensationVSAvoidproduct identification accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system implements feedback by continuously comparing product signals against reference element signals and using this comparison to adjust identification decisions. The reference element provides real-time feedback about environmental conditions and edge effects, allowing the system to dynamically compensate and maintain high identification accuracy.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The reference element acts as a mediator that captures and quantifies edge effects, allowing the system to subtract these effects from product measurements. This intermediary approach provides more effective compensation than direct product measurement alone, improving both measurement precision and identification reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If light scattered by products is detected to identify suitable versus inferior products, then product differentiation is possible, but edge effects cause incorrect identification

Engineering Contradiction:
Improveproduct differentiation capabilityVSAvoididentification accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The reference element serves as a mediator that establishes a baseline for what constitutes normal light scattering characteristics. By comparing product scattering patterns against this reference baseline, the system can differentiate between suitable and inferior products while filtering out edge effect artifacts that would otherwise cause misidentification.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system utilizes parameter changes in the temporal domain by alternating measurement between products and reference element. This allows separation of spatial parameters (product characteristics) from temporal parameters (edge effects), enabling accurate product differentiation despite the presence of edge effects.

Inventive Principle:
Principle #35Parameter changes

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

This approach effectively eliminates the influence of edge effects, allowing for precise identification and removal of inferior or strange products by distinguishing their light disturbances from those of suitable products, enhancing the accuracy of the sorting process.

Implementation Method 1

at least one light beam is directed to these products which move according to a certain direction through a detection zone, such that this light beam is at least partly scattered and/or reflected by said products

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

this light beam is at least partly scattered and/or reflected by said products

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

They illuminate these products with a stream of light which they detect. The products will hereby at least partly disturb this stream of light

Methodology Applied
Scientific EffectLight disturbance: Scattering

Data Source

PatentEP2186576B1Method and device for sorting products
Publication Date: 2015.08.12 TOMRA SORTING NV
  • EP2186576B1 patent drawingFigure 1~2
  • EP2186576B1 patent drawingFigure 3
  • EP2186576B1 patent drawingFigure 4~9

AI summary

The invention relates to a device and a method for sorting products (5), whereby these products move in a product flow through a detection zone (6), whereby a light beam is moved over the product flow by means of a scan such that the light beam (9) is at least partly scattered and/or directly reflected by said products (5), whereby the scattered light and/or the directly reflected light enters a detector (23) which generates a detection signal, whereby products are discerned by means of said detection signal. A stream of light is generated in the detection zone (6) between a reference element and said scan means and the intensity of this stream of light is discerned and when this intensity exceeds a preset value, a product which is hit by the light beam (9) will be qualified as a suitable product or as an inferior or strange product.