Gate Light Grid with Secondary Beams for Continuous Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing gate protection systems using light grids face challenges with high technical effort and risk of wear due to the need for optical devices and complex alignment on moving elements, and they struggle to maintain continuous monitoring of the closing edge movement, leading to unmonitored gaps and increased complexity.

Innovation Solution

The method and device employ a light grid with increased distances between protective beam positions, utilizing secondary protective beams that switch from active to passive states in synchronization with the closing movement, ensuring continuous monitoring and reduced complexity by arranging the light grid within the door frame, with leading and trailing secondary beams enhancing the monitoring coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optical devices and complex alignment are arranged on moving elements for gate protection, then object detection capability is improved, but technical effort and risk of wear increase

Engineering Contradiction:
Improveobject detection capabilityVSAvoidtechnical effort and wear risk
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of arranging optical devices on the moving gate, the patent inverts the arrangement by placing the light grid on the stationary door frame. The light transmitters and receivers are fixed on the frame, eliminating the need to attach optical components to the moving gate and its connecting lines, thus reducing technical effort and wear risk while maintaining detection capability

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts the optical devices from the moving gate and places them on the stationary door frame. This separation removes the complexity of arranging and aligning optical devices on the moving element, as the light grid becomes a fixed structure that requires no dynamic alignment with the gate movement

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If light barriers are used to monitor closing edge movement, then safety monitoring is improved, but computing effort and device complexity increase

Engineering Contradiction:
Improvesafety monitoringVSAvoidcomputing effort
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The light grid is segmented into multiple protective beam positions arranged along the closing movement path of the gate. Each position has spaced-apart light barriers that independently monitor specific segments of the closing edge, distributing the monitoring task across multiple simple binary sensors rather than requiring complex continuous tracking

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses multiple light barriers at each protective beam position spaced apart from each other, providing redundant monitoring coverage. This excessive action ensures that even if one barrier fails to detect, others can compensate, maintaining safety monitoring while keeping each individual sensor simple

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If protective beam positions are spaced closer together for continuous monitoring, then monitoring coverage is improved, but device complexity and technical effort increase

Engineering Contradiction:
Improvemonitoring coverageVSAvoidnumber of protective beam positions
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring area is segmented into discrete protective beam positions spaced at optimized intervals along the gate closing path. Each position contains multiple light barriers that together provide coverage for that segment, allowing spaced-apart positions to achieve continuous monitoring without requiring dense placement of every possible sensor

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple light barriers are placed at each protective beam position, providing excessive monitoring coverage at each location. This redundancy ensures that spaced-apart positions still achieve continuous monitoring coverage, as the multiple barriers at each position compensate for the larger spacing between positions

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 secure and uninterrupted high-speed closing processes with improved monitoring from start to finish, reducing the need for additional components on the gate and minimizing wear, while maintaining safety and reliability with a coarser grid pattern.

Implementation Method 1

a light grid (10) with a plurality of protective beams in protective beam positions (P1 to Pn)

Methodology Applied
Scientific EffectLight: Light

Data Source

PatentEP2853677B1Method and apparatus for securing gates
Publication Date: 2016.03.02 PEPPERL & FUCHS GMBH
  • EP2853677B1 patent drawingFigure 1~2
  • EP2853677B1 patent drawingFigure 3~4
  • EP2853677B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for securing gates with a light grid which emits a plurality of protective beams in protective beam positions, wherein the light grid is arranged such that its monitoring area coincides at least partially with a plane of movement of the gate to be secured, wherein the protective beams of the light grid are arranged transversely to a closing direction of the gate to be secured, wherein each of the protective beams forms an active state in which the switching state of this protective beam is evaluated for object detection, and wherein each of the protective beams forms a passive state in which the switching state of this protective beam is determined, but is not evaluated for object detection.The method is characterized in that each protective beam position emits, in addition to the protective beam, a leading secondary protective beam and a trailing secondary protective beam, and that the protective beam position is set to passive under the following plausibility condition: namely, when a preceding protective beam position is set to passive, and the protective beam position is switched on for the first time with its protective beam, and at least the trailing protective beam of the protective beam position and the immediately following leading secondary protective beam of the subsequent protective beam position switch on in a subsequent time interval adapted to the closing movement of the gate, and that the closing movement of the gate stops when an object is detected by at least one actively set protective beam and/or at least one actively set secondary protective beam. The invention also relates to a device for securing gates.