Wireless Dual Technology Displacement Sensor Power Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetic displacement sensor systems, particularly those using reed switches, face issues such as maintenance requirements, gap sensitivity, interference from ferromagnetic materials, and vulnerability to magnetic fields, leading to reliability and aesthetic concerns in security applications.

Innovation Solution

A displacement sensor system incorporating a dual-sensor approach, where an optical proximity sensor acts as a trigger to wake up a VL6180X range measuring sensor, eliminating the need for magnetic fields and reducing power consumption, thereby addressing the limitations of reed switch-based systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reed switches are used in magnetic displacement sensor systems, then the system can detect door or window states, but the system requires maintenance and has reliability issues due to magnet movement and switch failure

Engineering Contradiction:
Improvesensor system reliabilityVSAvoidmaintenance requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical reed switch system with an optical sensor system. The optical sensor detects the position of a reflective tape on the moving door/window without physical contact, eliminating wear and maintenance issues associated with mechanical switches and magnets.

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

Solution Approach 2:

The patent introduces a reflective tape as an intermediary element between the sensor and the moving door/window. The reflective tape reflects optical signals back to the sensor, enabling indirect detection of position without requiring direct contact or magnetic fields.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the gap between reed switch and magnets is minimized for security, then security is improved, but the system becomes more sensitive to misalignment and requires stronger magnets increasing size and cost

Engineering Contradiction:
ImprovesecurityVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent uses an optical sensor system that dynamically adapts to different gap distances. The sensor can accurately detect door/window states over a range of distances without requiring precise alignment, allowing installers to use larger gaps for easier installation while maintaining security.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the detection parameter from magnetic field strength to optical reflection detection. This allows the system to operate reliably over a wider range of distances and alignments, eliminating the need for precise gap control and strong magnets.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If spacers are used to lift magnets and reed switches away from metal surfaces, then interference from ferromagnetic materials is reduced, but installation becomes harder and requires additional tamper detection

Engineering Contradiction:
Improvesignal accuracyVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical spacer system with an optical sensor that can detect through or near metal surfaces without being affected by ferromagnetic interference. The optical detection method eliminates the need for physical spacers and their associated installation complexity and tamper detection requirements.

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

4Reliability

If strong magnetic fields are used in reed switch systems, then the reed switch can be reliably actuated, but the system becomes vulnerable to magnetic field attacks and affects operation of other components

Engineering Contradiction:
Improveswitch actuationVSAvoidmagnetic field interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the magnetic field-based reed switch actuation with optical detection. The optical sensor uses light reflection to detect door/window states, completely eliminating magnetic fields and their associated vulnerabilities to magnetic attacks and interference with other electronic components.

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

The dual-sensor system effectively determines door or window states without magnetic fields, reduces power consumption, and simplifies installation, enhancing reliability and battery life while minimizing false alarms and aesthetic concerns.

Implementation Method 1

an optical proximity sensor acts as a trigger to wake up a VL6180X range measuring sensor

Methodology Applied
Scientific EffectOptical proximity detection: Reflection

Implementation Method 2

a VL6180X range measuring sensor configured to transmit infrared light to measure the range from the analyzing sensor to the measuring point

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP3622491B1Wireless dual technology displacement sensor
Publication Date: 2023.09.06 TYCO FIRE & SECURITY GMBH
  • EP3622491B1 patent drawingFigure 1
  • EP3622491B1 patent drawingFigure 2
  • EP3622491B1 patent drawingFigure 3

AI summary

A wireless dual technology displacement sensor ("displacement sensor system") and method are disclosed. The displacement sensor system includes an analyzing sensor for determining a range to a measuring point and a trigger sensor for activating the analyzing sensor. The trigger sensor is an accelerometer or an optical proximity sensor (OPS), in examples. The analyzing sensor is preferably a time of flight range sensor. When installed as part of a door system having a door and door frame, for example, the trigger sensor detects movement of the door, and activates the analyzing sensor in response. The analyzing sensor then determines the range to the measuring point, such as the door frame. This two sensor system can be thus used to prevent the high current consumption of existing displacement sensor systems.