Virtual Temperature Heating Control with Single Sensor Fault Detection

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Solution Overview

Problem

Existing household appliances with single temperature sensors lack reliability and safety due to potential sensor failures, leading to incorrect readings and increased costs from redundant sensors, which are not only costly but also occupy valuable space.

Innovation Solution

A method using a single temperature sensor to control heating by updating a virtual temperature based on a characteristic curve, deactivating heating when unexpected temperature behavior is detected, and reactivating when normal behavior resumes, thereby ensuring safety and reducing component costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single temperature sensor is used, then device complexity and cost are reduced, but reliability deteriorates due to potential sensor failures

Engineering Contradiction:
Improvenumber of temperature sensorsVSAvoidheating control safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a virtual temperature value as an intermediary that mediates between the physical temperature sensor and the heating control system. This virtual temperature is calculated based on expected temperature behavior patterns, allowing the system to detect sensor failures without additional physical sensors. The virtual temperature acts as a buffer that translates sensor readings into reliable control decisions, resolving the contradiction between using fewer sensors and maintaining safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously monitoring whether measured temperature values align with expected temperature behavior. When deviations are detected, the system adjusts heating control accordingly. This feedback mechanism allows a single sensor to provide reliable information by comparing actual readings against expected patterns, maintaining safety without requiring redundant sensors.

Inventive Principle:
Principle #23Feedback

2Reliability

If additional temperature sensors are added for redundancy, then reliability improves, but device complexity and installation space requirements increase

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsensor wiring and evaluation electronics
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of creating physical copies through additional sensors, the patent creates a virtual copy of the temperature measurement system through calculated expected temperature values. This virtual temperature model serves as a software-based duplicate that provides the same safety function without requiring physical hardware duplication, thereby avoiding additional wiring and electronics.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent extracts the reliability function from the physical sensor domain and relocates it to the computational domain. By calculating expected temperature behavior and comparing it with actual sensor readings, the system separates the measurement function (performed by the single sensor) from the validation function (performed by the control unit), eliminating the need for redundant physical sensors and their associated complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If heating is switched off immediately upon detecting unexpected temperature behavior, then safety is improved, but productivity deteriorates due to premature shutdown

Engineering Contradiction:
Improveoverheating protectionVSAvoidheating availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the heating control adaptive rather than static. Instead of immediately switching off heating upon any temperature anomaly, the system dynamically adjusts control based on the degree and duration of deviations from expected behavior. The heating can be modulated or temporarily suspended and restarted, creating a dynamic response that maintains safety while minimizing interruptions to productivity.

Inventive Principle:
Principle #15Dynamics

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 maintains equivalent or improved reliability and safety without redundant sensors, reducing costs and component failure risks while preventing overheating damage.

Implementation Method 1

continuously measuring real temperature values Cm representing the temperature of the area to be heated with a single temperature sensor

Methodology Applied
Scientific EffectThermal detection: Thermal Radiation

Implementation Method 2

a heater for an area to be heated, having an adjustable heating power and one or more adjustable heating modes

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3291043B1Heater control of a household appliance using virtual temperature
Publication Date: 2019.01.02 MIELE & CO KG
  • EP3291043B1 patent drawingFigure 1
  • EP3291043B1 patent drawingFigure 2
  • EP3291043B1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling a heating of an area of ​​a household appliance to be heated, comprising activating the heating, specifying a temperature start value Cs, updating over time a virtual temperature Cv of the area to be heated, starting with the temperature start value Cs, based on a Characteristic curve of the heating, continuous measurement of real temperature values ​​Cm, which represent the temperature of the area to be heated, with a single temperature sensor, continue using the current temperature value Cm as the temperature start value Cs, if the difference between two consecutive temperature values ​​Cm indicates a normal state of the temperature sensor can be detected, and deactivation of the heating if the difference between the two consecutive temperature values ​​Cm indicates a fault condition of the temperature sensor and the virtual temperature Cv exceeds a limit value.