Resistive Element Frost Detection Without Prior Surface Knowledge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing frost detection methods require prior knowledge of the surface and environmental properties, limiting their applicability and effectiveness.
Innovation Solution
A method that analyzes the thermal response of a resistive element during heating, characterizing temperature evolution using the Laplace equation, distinguishing between diffusive and Dirichlet boundary conditions to detect frost without a priori knowledge of the surface or environment, employing a linearity parameter calculated through ordinary least squares estimation in a logarithmic time frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If methods require prior knowledge of surface and environmental properties to detect frost, then detection accuracy can be improved for specific conditions, but the adaptability and field of application are limited
Solution Approach 1:
The patent applies universality by creating a frost detection method that works across multiple surface types and environmental conditions without requiring prior knowledge of specific properties. The system uses a standardized heating protocol and temperature analysis approach that is universally applicable to any surface where frost detection is needed, eliminating the need for surface-specific calibration or parameter adjustment.
Solution Approach 2:
The patent employs parameter changes by transforming the detection approach from relying on known surface parameters to analyzing the temporal evolution of temperature parameters during controlled heating. By monitoring how temperature changes over time rather than relying on static surface property knowledge, the method adapts to different surfaces through dynamic parameter observation rather than predetermined parameter settings.
2Reliability
If a resistive element is heated to melting temperature and temperature is measured during thermal relaxation, then frost detection is possible through comparison to reference curve, but the method requires specific adjustment for each surface type
Solution Approach 1:
The patent extracts the essential detection signal from the complex thermal relaxation process by focusing specifically on the temperature evolution pattern during controlled heating. Rather than requiring complete thermal relaxation curves and reference comparisons for each surface type, the method extracts the key diagnostic information from the heating phase itself, simplifying the detection process while maintaining reliability.
Solution Approach 2:
The patent inverts the conventional approach by instead of measuring temperature during cooling/relaxation after heating, it measures and analyzes temperature evolution during the heating process itself. This inversion allows the method to detect frost based on thermal response characteristics during heating, eliminating the need for post-heating relaxation measurements and surface-specific reference curves.
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
Enables reliable frost detection on various surfaces without prior knowledge of thermal properties, ensuring consistent and accurate identification of frost presence by stabilizing temperature evolution during melting.
Implementation Method 1
a resistive element (12) able to heat up by Joule effect under the effect of an electric current passing through it
Implementation Method 2
a part forming a temperature probe (12), for measuring the temperature of the resistive part
Implementation Method 3
If ice is present, its fusion absorbs thermal energy, which modifies the kinetics of the rise in temperature of the element
Data Source
Figure 1~2C
Figure 3~4
Figure 5A~5D
AI summary
A system for detecting frost on a surface (18) comprises a resistive element (12) in contact with the surface (18), a current generator (22) connected to the resistive element (12), a sensor (28) measuring the temperature of the resistive element (12), and a calculation unit (38) capable of determining the presence of ice on the surface (18) depending on the measurement delivered by the sensor. The generator (22) injects an electrical current into the element (12) in order to bring same to a temperature higher than the melting temperature of the ice. The calculation unit (38) determines a difference between the temperature measured during the heating of the element and an exponential growth function, and detects frost on the surface (18) if the difference is greater than a predefined detection threshold.