Contact Detection Device Using Modulated Heat Flow

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Solution Overview

Problem

Existing contact detection devices fail to reliably detect physical contact between an object and the sensor when the object has the same temperature as the sensor, and can be corrupted by ambient temperature changes, leading to false indications.

Innovation Solution

A contact detection device that uses a heater to provide a modulated heat flow, generating a modulated heat signal which changes when contact is made, ensuring a contact indication signal is produced regardless of ambient temperature fluctuations, using a demodulator to isolate the modulated heat flow effects from ambient temperature influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a contact sensor measures temperature difference to detect physical contact, then contact detection is simple, but the sensor fails to detect contact when the object has the same temperature as the sensor

Engineering Contradiction:
Improvecontact detection simplicityVSAvoidcontact detection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies periodic action by using a heater to provide a modulated heat flow to the contact surface at a specific frequency. This periodic heating creates a modulated temperature pattern that allows the sensor to detect contact through changes in heat transfer characteristics, even when the average temperature matches the object temperature. The periodic modulation enables reliable contact detection by creating detectable variations in the thermal signal.

Inventive Principle:
Principle #19Periodic action

2Device complexity

If a contact sensor uses ambient temperature measurement, then the device structure is simple, but ambient temperature changes cause false contact indications

Engineering Contradiction:
Improvesensor structure complexityVSAvoidcontact indication accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sensor uses periodic modulation of the heat flow at a known frequency to create a distinctive thermal signature. By measuring the modulated heat signal at this specific frequency, the system can distinguish between actual contact events and ambient temperature variations. The periodic action creates a reference signal that filters out random environmental temperature changes, preventing false indications while maintaining relatively simple device structure.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements feedback by continuously monitoring the modulated heat signal and using this information to determine contact status. The system measures the heat transfer characteristics during periodic heating cycles and uses this feedback to reliably indicate contact presence or absence, effectively compensating for ambient temperature changes through active signal processing rather than passive temperature measurement.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If a contact sensor waits for temperature difference to detect contact, then energy consumption is low, but detection response time is delayed

Engineering Contradiction:
Improvesensor energy consumptionVSAvoidcontact detection time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The sensor employs periodic heating cycles that actively create temperature variations on the contact surface. This active modulation accelerates the thermal response, allowing the sensor to detect contact much faster than passive waiting for natural temperature differences to develop. The periodic energy input maintains a dynamic thermal state that enables rapid detection while keeping overall energy consumption manageable through controlled duty cycles.

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

The solution ensures reliable detection of physical contact by guaranteeing a change in the modulated heat signal when contact is made, reducing false positives and improving overall reliability by isolating the contact indication from ambient temperature variations.

Implementation Method 1

a heater for providing a modulated heat flow

Methodology Applied
Scientific EffectModulated heat flow: Conduction (thermal)

Implementation Method 2

The Seebeck voltage is indicative for a temperature. The disclosed micro sensor shall predominantly be employed for measuring high temperatures

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentEP2454572B1Physical contact detection device
Publication Date: 2016.12.28 KONINKLIJKE PHILIPS NV
  • EP2454572B1 patent drawingFigure 1
  • EP2454572B1 patent drawingFigure 2
  • EP2454572B1 patent drawingFigure 3

AI summary

The present invention is related to a contact detection device (100) for detecting a contact between the contact detection device (100) and an object (800), a method (400), a diagnostic device and further to a computer program. The invention seeks to improve the reliability of contact sensors. The contact detection device (100) comprises a heater (110) for providing a modulated heat flow (112). A modulated heat signal (122) is generated in dependence of the modulated heat flow (112). A physical contact with an object (800) causes a change in the modulated heat flow (112) that effects the modulated heat signal (122). As the heat flow is modulated, a change in the modulated heat signal (122) is quasi assured. A contact determination unit (130) of the contact detection device (100) derives a contact indication signal (132) indicating at least either the presence or the absence of the physical contact in from the modulated heat signal (122), preferentially by means of a demodulator (134).