Protective Door Monitoring Using 3-Axis Magnetometer Signals

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Solution Overview

Problem

Existing security systems for protecting hazardous areas on machines face reliability issues due to mutual interference between transponder-based monitoring means, leading to potential malfunctions and unauthorized access.

Innovation Solution

Incorporating a 3-axis magnetometer as a second monitoring means that generates direction-dependent signals, providing precise movement tracking and eliminating interference with the first transponder-based monitoring means, along with a light barrier for enhanced security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a transponder-based first monitoring device is used to detect locking state, then the locking status can be identified, but a second transponder-based monitoring device positioned close to it causes mutual interference and malfunctions

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidmutual interference between transponders
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the second transponder-based monitoring device with a sensor-based monitoring device that detects position through physical sensing (e.g., magnetic fields, optical sensors, or mechanical position sensors) rather than through transponder communication. This substitution eliminates the mutual interference between transponders while maintaining the ability to monitor door position for safety purposes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a second monitoring device is added to detect malfunctions of the first monitoring device, then safety is enhanced, but the complexity of the system increases

Engineering Contradiction:
ImprovesafetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensor-based second monitoring device serves multiple functions: it detects the actual position of the separating protective device, monitors for malfunctions of the first monitoring device, and provides redundant safety verification. By designing the second device to perform multiple monitoring tasks, the patent enhances safety without proportionally increasing system complexity.

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

3Area of stationary object

If transponders are positioned close to each other to monitor locking state, then space is saved, but they interfere with each other causing malfunctions

Engineering Contradiction:
Improvespace utilizationVSAvoidsignal interference
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the interfering transponder-based second monitoring device with a sensor-based device that can detect position through non-interfering physical fields or mechanisms. This allows both monitoring devices to be positioned in close proximity without experiencing mutual interference, thereby saving space while eliminating signal interference problems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Significantly increases the functional reliability of the security system by accurately tracking complex movements and preventing unauthorized access through diverse and non-interfering monitoring means, ensuring safe operation of machines.

Implementation Method 1

The sensor, which is designed to be diverse with respect to the first monitoring means, is a 3-axis magnetometer

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP3128220B1Safety system
Publication Date: 2023.07.05 EUCHNER GMBH & CO KG
  • EP3128220B1 patent drawingFigure 1
  • EP3128220B1 patent drawingFigure 2~3

AI summary

The invention relates to a safety system (1) for a separating protective device (4) comprising a first monitoring means for monitoring whether the separating protective device is locked by means of an interlock (5) and a second monitoring means for detecting the position of the separating protective device. The second monitoring means includes a sensor, different from the first monitoring means, that generates direction-dependent signals.