Homogeneous Light Curtain for High-Resolution Object Classification

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Solution Overview

Problem

Conventional light grids are limited in their ability to classify objects based on shape, size, and orientation, struggling to detect objects with thin or transparent areas, and those that rotate while passing through the surveillance area, with resolution dependent on beam spacing, leading to inaccurate counting and classification of objects like entangled springs or mixed screws.

Innovation Solution

A light curtain device with a homogeneous touch panel, where multiple transmitter elements emit wide-angle radiation and multiple receiver elements detect this radiation, allowing for a single signal to be combined, independent of transmitter-receiver element spacing, enabling high-resolution detection and classification of objects based on time-dependent extent, dwell time, and shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional light grids with individual focused beams are used, then the structure is simple and easy to manufacture, but the resolution is limited by beam spacing and objects with thin or transparent areas cannot be reliably detected

Engineering Contradiction:
Improvedetection resolutionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The transmitter is divided into multiple independently controllable emitting elements and the receiver into multiple detecting elements, allowing the system to create multiple virtual beams through selective activation and combination, achieving high resolution without requiring physically spaced individual beam sources

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a 1D array of focused beams to a 2D matrix of emitting and detecting elements, enabling the creation of multiple virtual beam paths through combinatorial activation, thereby achieving higher resolution in the measurement dimension without proportionally increasing physical complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple transmitting and receiving elements are arranged closely to improve resolution, then detection precision increases, but the system becomes more complex and difficult to manufacture

Engineering Contradiction:
Improveobject size measurement accuracyVSAvoidassembly difficulty
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple emitting elements and multiple detecting elements are combined into integrated transmitter and receiver units respectively, where the control unit manages the coordinated activation and signal combination, simplifying the physical assembly while maintaining high measurement precision through virtual beam synthesis

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If individual directed beam paths are used for each transmitter-receiver pair, then the system structure is simple, but objects rotating or moving arbitrarily cannot be accurately classified

Engineering Contradiction:
Improveobject classification capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically activates specific emitting and detecting elements based on the detected object's position, orientation, and movement pattern, allowing the virtual beam configuration to adapt in real-time to rotating or arbitrarily moving objects, thereby achieving accurate classification without fixed beam geometry

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit continuously receives signals from the detecting elements, analyzes object characteristics, and adjusts the activation pattern of emitting elements accordingly, creating a feedback loop that enables accurate tracking and classification of rotating or moving objects through adaptive virtual beam steering

Inventive Principle:
Principle #23Feedback

4Reliability

If focused individual beams are used, then the system is easy to control, but sensitivity to disturbances from thin or transparent areas is reduced

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system combines signals from multiple detecting elements that receive radiation from multiple emitting elements, creating redundant measurement paths that enhance sensitivity to partial interruptions caused by thin or transparent objects, while the control unit processes the combined signals to maintain reliable detection

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses excessive action by having each detecting element receive radiation from multiple emitting elements rather than a single paired source, creating multiple overlapping measurement paths that increase the probability of detecting partial interruptions from thin or transparent areas, with the control unit filtering redundant information

Inventive Principle:
Principle #16Partial or excessive action

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 allows for reliable detection, counting, and classification of objects with improved sensitivity to disturbances, capable of distinguishing objects of different dimensions and shapes, even when rotating or partially transparent, with resolutions below 0.5mm, and visualizing object shapes.

Implementation Method 1

A transmitter block (29) with a transmitter unit (17) having n transmitting elements (19) to emit radiation e.g. in the form of light

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

A receiver block (31) with a receiver unit (23) having m receiving elements (25) to detect the radiation emitted by the transmitting elements (19)

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Implementation Method 3

which emit radiation e.g. in the form of light, in particular essentially homogeneously over a planar area

Methodology Applied
Scientific EffectHomogeneous radiation distribution: Light

Data Source

PatentEP3413014B1Device and method for detecting and measuring objects
Publication Date: 2023.07.19 BRAUSS STEPHAN
  • EP3413014B1 patent drawingFigure 1~2
  • EP3413014B1 patent drawingFigure 3~5
  • EP3413014B1 patent drawingFigure 6~7

AI summary

The invention relates to a method and a device for detecting and measuring objects as they pass through a monitoring area (39) defined by one or more touch fields (13). A touch field is generated by a transmitter block (29) and a receiver block (31) arranged opposite it. A transmitter block contains a plurality of transmitting elements (19) that emit radiation. A receiver block contains a plurality of receiving elements (25) that measure radiation. A touch field is a substantially homogeneous radiation plane. The radiation from a transmitting element strikes a plurality of receiving elements, and a receiving element receives radiation from a plurality of transmitting elements. The radiation measured by the receiving elements is combined into a signal in the receiver block. The resolution achievable in this way is significantly finer than the grid determined by the local arrangement of the transmitting or receiving elements.During the time an object is in the touch field, numerous individual measurements are taken. The shadowing of the receiving elements is determined by comparing the signal strengths when the touch field is covered and uncovered, and the projected extent of the object is calculated from this. By sequentially combining the individual measurements, the object's dwell time in the touch field, its maximum projected extent, its projected area, and its projected shape can be determined. Based on the data collected about an object, it can be classified, counted, and its shape visualized.