Optoelectronic Sensor Edge Detection with Variable Light Spacing

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Solution Overview

Problem

Existing optoelectronic sensors face challenges in reliably detecting object edges, especially when objects have varying radii of curvature and are closely aligned, as they are heavily dependent on the radius of curvature for energetic weighing methods and fail with strongly rounded objects.

Innovation Solution

An optoelectronic sensor with at least three light emitters and a selection mechanism for different light transmitter spacings, allowing for adaptable edge detection using energetic weighing or distance difference methods, and enabling dynamic adjustment based on expected object edge curvature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single fixed spacing between light transmitters is used, then the device structure is simple, but the sensor fails to reliably detect object edges when objects have varying radii of curvature or are strongly rounded

Engineering Contradiction:
Improveobject edge detection reliabilityVSAvoidlight transmitter arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements multiple light transmitter pairs with different spacings (first pair with spacing d1, second pair with spacing d2) that can be selectively activated. This dynamic configuration allows the sensor to adapt to varying object geometries including strongly rounded objects, maintaining reliable edge detection across different application scenarios without requiring a fixed complex structure.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If two separate light transmitters with different spacings are used, then the sensor can detect transitions between consecutive objects, but the device complexity increases

Engineering Contradiction:
Improveapplication scenario adaptabilityVSAvoidsensor structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs the optoelectronic sensor with multiple light transmitter pairs (first pair with spacing d1, second pair with spacing d2) that can be selectively activated based on the application scenario. This multi-functional design allows the same sensor to handle various object types including strongly rounded objects, objects with different radii of curvature, and closely aligned objects, thereby achieving universal adaptability without proportionally increasing overall device complexity.

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

3Productivity

If objects are conveyed in close proximity, then the productivity is high, but the transition detection between objects becomes difficult

Engineering Contradiction:
Improveobject conveyance speedVSAvoidobject transition detection precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the light transmission function into multiple pairs of light transmitters with different spacings. The first pair with spacing d1 and the second pair with spacing d2 can be selectively activated to detect object transitions. This segmentation allows the sensor to maintain high measurement precision for object transitions even when objects are conveyed in close proximity, thereby supporting high productivity without sacrificing detection accuracy.

Inventive Principle:
Principle #1Segmentation

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

Enables reliable detection of object edges across different application scenarios by selecting the optimal light transmitter spacing and evaluation method, improving detection accuracy and flexibility.

Implementation Method 1

at least three light emitters (15) for generating respective collimated or focused transmitted light beams (21)

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

at least one light receiver (17) for receiving light emitted by the transmitted light beams (21) on one object generated light spots

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP2801786B1Opto-electronic sensor and method for detecting object edges
Publication Date: 2019.01.02 SICK AG
  • EP2801786B1 patent drawingFigure 1
  • EP2801786B1 patent drawingFigure 2~3
  • EP2801786B1 patent drawingFigure 4

AI summary

An optoelectronic sensor for detecting object edges comprises at least three light emitters arranged such that at least two different distances exist between each pair of light emitters. An evaluation unit is configured to perform a combined evaluation of an image of a light spot generated by the emitted light beams of a first light emitter, captured by a light receiver, and of an image of a light spot generated by the emitted light beams of another light emitter, both captured by a light receiver. The pair of light emitters used for the combined evaluation can be selected from at least two differently spaced pairs of light emitters, depending on a selection criterion.