Cooked Food Core Temperature Estimation from Misplaced Sensors

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Solution Overview

Problem

Existing methods for determining the core temperature of food during cooking are prone to errors due to incorrect placement of temperature sensors, leading to inaccurate cooking process control and documentation, especially when the sensor does not hit the core of the food.

Innovation Solution

A method that solves the differential equation for heat conduction in food items of various shapes, using previously determined solutions based on shape, size, and thermal properties, and incorporates data from multiple sensors to improve the accuracy of core temperature estimation without precise knowledge of boundary conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single temperature sensor is used to measure core temperature, then the device complexity is reduced, but the measurement precision deteriorates when the sensor is incorrectly placed

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the temperature measurement task into multiple segments by using several temperature sensors (first, second, and third temperature sensors) positioned at different locations within the food item. This segmentation allows the system to capture temperature data from multiple points, enabling more accurate determination of core temperature even if one sensor is misplaced, thereby resolving the contradiction between device simplicity and measurement accuracy.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If multiple temperature sensors are placed in the food, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-determining a set of solutions to the heat conduction differential equation for various food shapes, sizes, and thermal properties before the actual measurement. During measurement, the system only needs to select from these pre-prepared solutions based on the measured temperature data, which simplifies the real-time processing complexity while maintaining high measurement precision through multiple sensors.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the sensor placement is not precise, then the ease of operation improves, but the measurement precision deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring temperature data from multiple sensors and using this information to select the most appropriate pre-determined solution from the set of differential equation solutions. The system feedback mechanism allows it to compensate for imprecise sensor placement by choosing the solution that best fits the observed temperature distribution, thereby maintaining measurement precision while ease of operation.

Inventive Principle:
Principle #23Feedback

4Device complexity

If extrapolation is performed along the sensor axis only, then the calculation complexity is reduced, but the measurement precision deteriorates when the coldest point is not on the axis

Engineering Contradiction:
Improvecalculation complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from one-dimensional extrapolation along the sensor axis to a multi-dimensional approach by considering temperature data from multiple sensors positioned at different spatial locations. By incorporating measurements from sensors in three-dimensional space and selecting from pre-determined solutions that account for various food geometries, the system accurately locates the coldest point (core temperature) regardless of whether it lies on any single sensor axis, thus resolving the contradiction between calculation simplicity and measurement accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides a more precise estimation of the actual core temperature, even with poor sensor placement, by selecting the best-fitting temperature profile from a set of solutions, ensuring accurate cooking control and documentation.

Implementation Method 1

A temperature sensor spike, which contains one or more thermocouples and possibly other sensors, is usually used.

Methodology Applied
Scientific EffectThermocouple: Thermocouple

Implementation Method 2

a method for determining the core temperature of a food item to be cooked during a cooking process... solves the differential equation for heat conduction in food items

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP2063183B1Method for determining core temperature of cooked food
Publication Date: 2013.06.19 RATIONAL AG
  • EP2063183B1 patent drawingFigure 1
  • EP2063183B1 patent drawingFigure 2
  • EP2063183B1 patent drawingFigure 3

AI summary

The invention relates to a method for determining the core temperature of an item to be cooked during a cooking process in a cooking chamber of a cooking appliance, which comprises at least one heating device, a temperature sensor that can be at least partially inserted into the item to be cooked, a computing unit and a memory, wherein during the cooking process the item to be cooked is at least temporarily is heated from the outside to the inside, at least one temperature is measured with the aid of the temperature sensor at at least one point inside the food to be cooked at least twice or continuously, and a differential equation in the form of a heat conduction equation is used to determine the core temperature from the measured temperatures, with a Solution, especially approximate solution, the differential equation that describes the heat diffusion inside the food, from a variety of previously determined solutions, especially approximate solutions, the differential equation based on the temporal development of ge measured temperature and under the assumption that at least one characteristic of a thermal property of the food is constant over the food is selected.