Method for controlling a cooking process in a cooking device and cooking device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cooking methods struggle to adapt cooking processes to different products and processes reliably without load detection, often resulting in inconsistent results due to variations in load, preheating times, and device types, leading to inefficient energy use and potential overcooking or undercooking.

Innovation Solution

The method focuses on determining specific heat input as the controlling parameter, using a heat flow integral calculated with a heat transfer coefficient, cooking medium temperature, and surface temperature to ensure consistent cooking outcomes, allowing for adaptation to various products and processes without load detection, and includes features like adjustable fan speed and humidity consideration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If load detection methods (weight sensors, optical image recognition) are used to adjust cooking parameters, then cooking consistency is improved, but device complexity increases

Engineering Contradiction:
Improvecooking consistencyVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential cooking control parameter (heat flow integral) from complex load detection systems. Instead of using weight sensors or optical recognition, the invention calculates a simplified heat flow integral based on temperature measurements and cooking time, which captures the essential cooking state without requiring complex detection hardware.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical load detection systems (weight sensors) with a thermal-field-based calculation approach. The heat flow integral is computed from temperature-time data, substituting direct mechanical measurement with indirect thermal field analysis, thereby eliminating complex sensors while maintaining cooking control accuracy.

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

2Loss of energy

If temperature-based load detection is used to adjust cooking time, then energy efficiency is improved, but reliability deteriorates due to sensitivity to preheating variations and door opening

Engineering Contradiction:
Improveenergy efficiencyVSAvoidreliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent performs preliminary integration of heat flow during the cooking process to build the heat flow integral before making control decisions. By continuously accumulating thermal energy data throughout cooking, the system establishes a robust baseline that is insensitive to transient disturbances like door opening or preheating variations, enabling reliable energy-based control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback control based on the heat flow integral, where the integrated thermal energy measurement continuously informs cooking parameter adjustments. This feedback mechanism compensates for disturbances by comparing actual heat flow accumulation against expected values, maintaining reliability while optimizing energy efficiency.

Inventive Principle:
Principle #23Feedback

3Temperature

If calibration processes are run for maximum load to maintain target temperature, then temperature stability is improved, but productivity decreases due to wasted baking time

Engineering Contradiction:
Improvetarget temperature stabilityVSAvoidbaking time efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent implements dynamic cooking control where the heat flow integral threshold is adjusted based on actual cooking conditions and product characteristics. Instead of fixed calibration for maximum load, the system dynamically adapts the termination criterion to match real-time thermal energy accumulation, optimizing both temperature stability and cooking time efficiency for different load conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from fixed temperature maintenance to variable heat flow integral threshold. By using the integrated thermal energy measure rather than instantaneous temperature, the system adapts cooking termination to actual energy input, eliminating the need for conservative maximum-load calibration and improving productivity while maintaining quality.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If extensive series of tests are conducted to determine process parameter changes for all product and device combinations, then adaptability is improved, but loss of time increases

Engineering Contradiction:
Improveproduct and process adaptabilityVSAvoidtesting time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent creates a universal heat flow integral-based control method that applies across different products, devices, and cooking conditions. The integrated thermal energy approach serves as a common language for cooking state assessment, eliminating the need for separate calibration curves for each product-device combination and enabling broad adaptability through a single unified methodology.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent transforms the control approach by changing from product-specific parameter tables to a universal heat flow integral calculation. This parameter transformation allows the same computational method to adapt to different products and devices by simply adjusting the integration threshold, dramatically reducing testing requirements while maintaining versatility.

Inventive Principle:
Principle #35Parameter changes

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 adaptation of cooking processes, reduces the need for extensive testing, and ensures consistent product quality by focusing on specific heat input, accommodating different loads and device types, while minimizing energy waste and preventing overcooking.

Implementation Method 1

a heating device (18) with which the atmosphere present in the cooking chamber (12) can be heated

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a fan wheel (20) with which the atmosphere present in the cooking chamber (12) can be heated and circulated

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

A steam module can also be integrated into the heating device (18) in order to bring the humidity of the cooking medium to a predetermined value

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

the specific heat input into the product to be cooked, which is integrated for each individual cooking process

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 5

the specific heat input into the product to be cooked, which is integrated for each individual cooking process

Methodology Applied
Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentEP2469173B1Method for controlling a cooking process in a cooking device and cooking device
Publication Date: 2020.08.12 RATIONAL AG
  • EP2469173B1 patent drawingFigure 1
  • EP2469173B1 patent drawingFigure 2
  • EP2469173B1 patent drawingFigure 3

AI summary

The method involves determining a specific heat input in a product to-be-cooked. The specific heat input is integrated over the cooking time. The cooking process is finished, when the heat flux integral reaches a predetermined value. The specific heat input is determined from the product of an assumed heat transfer coefficient for the current cooking process and a driving temperature difference. An independent claim is also included for a cooking appliance with a cooking chamber.