Single Thermal Sensor Presence Detection Using Temporal Variance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing infrared radiation detection systems for presence and movement detection in environments like hospitals or elderly care facilities are often complex and costly due to the need for multiple thermocouple detectors, which can be impractical for cost-sensitive applications.

Innovation Solution

A single thermal sensor, such as a thermocouple or bolometer, generates signals indicative of temperature differences over time to determine presence and movement indications without the need for instantaneous detection, using adaptive thresholds and variance analysis to differentiate between presence and movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple thermocouple detectors are used to detect presence and movement, then detection reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple detection functions (presence detection and movement detection) into a single thermocouple detector by analyzing temperature variations over time. The controller processes a sequence of temperature measurements to distinguish between presence (temperature change) and movement (rapid temperature change), eliminating the need for multiple detectors while maintaining detection reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses dynamic analysis of temperature variations over time to differentiate between presence and movement. By evaluating the rate of change and pattern of temperature measurements across multiple time points, the controller can dynamically determine whether a person is merely present or actively moving, resolving the contradiction between using simple sensors and achieving reliable multi-function detection

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple thermocouple detectors are used for presence and movement detection, then detection accuracy is improved, but cost increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges multiple detection capabilities into a single thermocouple detector system. The controller analyzes temporal patterns in temperature measurements from one detector to achieve both presence and movement detection with high accuracy, significantly reducing system cost compared to using multiple detectors

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The controller acts as an intermediary that processes raw temperature data from the single thermocouple detector and extracts multiple pieces of information (presence, movement) through algorithmic analysis. This intermediary processing layer enables high detection accuracy while maintaining low hardware cost

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single thermal sensor is used to detect presence and movement, then device complexity is reduced, but the ability to detect movement is worsened

Engineering Contradiction:
Improvedevice complexityVSAvoidmovement detection capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system overcomes the limitation of a single static sensor by introducing temporal dynamics. The controller analyzes the rate of change and pattern of temperature measurements over multiple time points to detect movement. Rapid temperature changes indicate movement, while slower changes indicate mere presence, enabling reliable movement detection with a single sensor

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs periodic sampling of temperature measurements over time to detect movement patterns. By taking measurements at regular intervals and analyzing the temporal sequence, the controller can identify movement events even with a single thermal sensor, maintaining detection reliability while simplifying the device

Inventive Principle:
Principle #19Periodic 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 simplifies the detection system by using a single sensor, reducing complexity and cost while maintaining effective presence and movement detection, and can also estimate sleep quality based on movement patterns.

Implementation Method 1

a thermal sensor generating signals indicative of a difference between a reference temperature and a temperature of a part exposed to infrared radiation

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

a single thermal sensor (sometimes referred to as a pyrometer), such as a thermocouple sensor

Methodology Applied
Scientific EffectThermocouple effect: Thermocouple

Data Source

PatentEP2974649B1Device for detecting infrared radiation and method for determining an indication of presence and an indication of movement
Publication Date: 2022.03.02 LEGRAND FRANCE SA
  • EP2974649B1 patent drawingFigure 1~2
  • EP2974649B1 patent drawingFigure 3~5
  • EP2974649B1 patent drawingFigure 6~7

AI summary

The invention relates to an infrared radiation detection device comprising a thermal sensor (30) generating signals (TF, TC) indicative of a difference between a reference temperature (TF) and a temperature of a part exposed to infrared radiation (TC), with a module (40) for determining a presence indication (PRES) and a movement indication based solely on a plurality of values ​​of said difference recorded over a time interval. A method for determining the presence indication (PRES) and the movement indication is also described.