Multiple-optical-axis sensor muting sequence optimization

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Solution Overview

Problem

The existing multiple-optical-axis photoelectric sensor systems face challenges in reducing start-up time and minimizing 'muting errors' that lead to productivity losses, requiring extensive manual intervention and trial-and-error processes during facility start-up and workpiece changes.

Innovation Solution

The system provides statistical information to users for setting accurate muting sequences, eliminating the need for trial-and-error methods by analyzing and optimizing muting sequences based on actual operational data, ensuring proper alignment of productivity and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the muting function disables the whole detection area based on two independent muting signals with strict sequence checking, then the safety function is established, but the productivity is degraded due to frequent stopping of the production facility

Engineering Contradiction:
Improvesafety functionVSAvoidproduction facility operation
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The detection area is divided into multiple independent optical axes (first optical axis and second optical axis), allowing selective muting of specific axes rather than the entire detection area. This segmentation enables the system to maintain safety for specific dangerous zones while allowing production to continue in other areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The muting function transitions from a static whole-area disablement to a dynamic selective-axis muting capability. The control unit can independently mute or unmute specific optical axes based on real-time conditions, providing flexible control that adapts to different operational requirements and minimizes production disruption.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the sequence of muting signals is strictly checked to prevent muting errors, then the safety is maintained, but the start-up time and adjustment time are increased due to trial-and-error processes

Engineering Contradiction:
Improvemuting sequence accuracyVSAvoidstart-up time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary testing by detecting workpieces during the start-up phase to automatically determine the actual muting sequence. This preliminary data collection enables the control unit to establish accurate muting sequences before full production begins, eliminating the need for time-consuming trial-and-error adjustments later.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms where the control unit monitors the actual muting sequence through workpiece detection and uses this information to automatically adjust and optimize the muting sequence. This feedback loop eliminates manual trial-and-error processes and reduces start-up time while maintaining safety.

Inventive Principle:
Principle #23Feedback

3Productivity

If the muting sequence is defined based on sensor installation position, workpiece shape, and conveying speed, then the muting function can be optimized, but the complexity of setup and adjustment increases when workpieces are switched

Engineering Contradiction:
Improvemuting function optimizationVSAvoidsetup and adjustment complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system performs self-adjustment by automatically detecting workpieces during operation and determining the actual muting sequence without requiring manual intervention. The control unit autonomously optimizes the muting sequence based on detected workpiece characteristics, eliminating the need for complex manual setup and adjustment when workpieces are switched.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically adjusts muting sequence parameters based on detected workpiece characteristics such as shape, size, and conveying speed. By automatically adapting these parameters rather than requiring manual reconfiguration, the system maintains optimization across different workpiece types while reducing setup complexity.

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 reduces start-up time and man-hours, enhances productivity by minimizing errors and optimizing muting sequences, achieving a balance between productivity and safety.

Implementation Method 1

The light projecting unit causes the light projecting elements to sequentially emit the light beam. The light receiving unit takes out the amount of light that each light receiving element receives from a corresponding light projecting element

Methodology Applied
Scientific EffectLight emission and detection: Light

Data Source

PatentEP2919043B1Multiple-optical-axis photoelectric sensor system, multiple-opticle-axis photoelectric sensor system control method, program, and recording medium
Publication Date: 2021.03.31 OMRON CORP
  • EP2919043B1 patent drawingFigure 1
  • EP2919043B1 patent drawingFigure 2
  • EP2919043B1 patent drawingFigure 3

AI summary

A start-up time of a production facility is shortened while generation of a muting error is suppressed, whereby productivity is improved. A multiple-optical-axis photoelectric sensor system (100) includes a projector (1), an optical receiver (2), a light blocking determination unit configured to make a light blocking determination whether each of optical axes formed between the projector (1) and the optical receiver (2) is in a light blocking state, and a muting processor configured to temporarily disable the light blocking determination on condition that a detection signal input from an external muting instrument changes according to a predetermined sequence. The muting processor determines the sequence of the detection signal from the muting instrument during the muting by dividing the sequence into a plurality stages. The muting processor accumulates and analyzes measurement information acquired in each stage, and decides an optimum setting value for a muting operation condition based on an analysis result.