Sauna Heater Object Detection Using Adaptive Heat Radiation Curves
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Solution Overview
Problem
Existing methods for detecting objects on a sauna heater are unreliable due to slow temperature changes and environmental variations, leading to potential fire risks, as they fail to accurately monitor heat radiation and adapt to changing conditions.
Innovation Solution
A system using a thermopile sensor to monitor heat radiation and construct a normal heat radiation curve, which is updated over time, compares real-time measurements to detect deviations and automatically switches off the heater to prevent fires, incorporating an overheat protection mechanism for safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a normal temperature sensor is used to monitor the steam room temperature, then the temperature can be tracked, but the detection is unreliable because the steam room warms up very slowly and the sensor does not give reliable information of the overall situation
Solution Approach 1:
The patent introduces an infrared sensor as an intermediary measurement device that directly monitors the heater surface temperature rather than relying on steam room air temperature. This intermediary sensor provides immediate feedback about actual heating conditions and object presence on the heater, resolving the reliability issue of traditional temperature sensors that only indirectly reflect heating status through slow steam room temperature changes.
Solution Approach 2:
The patent replaces the traditional temperature sensor-based mechanical/thermal monitoring system with an infrared radiation-based detection system. This substitution enables direct, real-time measurement of heater surface temperature and object detection without relying on the slow thermal conduction and convection processes that characterize traditional temperature sensing in sauna environments.
2Reliability
If an infrared sensor is used to detect objects on the stove, then object detection is possible, but the method is not reliable because conditions for infrared radiation change over time due to erosion of stones and ambient temperature variations
Solution Approach 1:
The patent implements a dynamic reference temperature curve that is continuously updated based on historical measurement data. Instead of using a fixed threshold, the system adapts to changing environmental conditions by learning the normal temperature progression pattern of the heater over time. This dynamic approach allows the system to distinguish between normal temperature variations due to stone erosion or ambient changes and abnormal conditions indicating objects on the heater.
Solution Approach 2:
The system incorporates feedback mechanisms where the infrared sensor continuously monitors heater temperature and compares it against the dynamic reference curve. The system learns from past operations and adjusts the reference curve accordingly, creating a self-adapting detection system that improves reliability over time while accounting for environmental variations and heater degradation.
3Reliability
If the sauna heater is monitored continuously, then fire safety is improved, but energy consumption and system complexity increase
Solution Approach 1:
The patent implements periodic monitoring at critical phases of heater operation, particularly during the heating-up phase when fire risk is highest. The infrared sensor activates and monitors temperature progression during these critical periods, then can reduce monitoring intensity or enter standby mode during stable operation phases. This periodic action approach maintains fire safety during high-risk periods while reducing overall energy consumption compared to continuous high-intensity monitoring.
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
Effectively detects obstacles near the sauna heater within minutes of startup, preventing fires by ensuring the heater remains off until safe conditions are confirmed, adapting to variations in sauna environments and maintaining reliability across different heater types and settings.
Implementation Method 1
The sensor preferably used in the invention is a thermopile sensor, which reacts on infrared radiation. A thermopile is an electronic device that converts thermal energy into electrical energy.
Implementation Method 2
The sensor preferably used in the invention is a thermopile sensor, which reacts on infrared radiation
Data Source
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AI summary
The invention is concerned with a method for detection of objects on a sauna heater and comprises the steps of construction of a normal set heat radiation curve by means of measurements over a time period and storing the heat radiation curve in a memory of a controller. The heat radiation measurements from a sauna heater are monitored over a corresponding time period by using a first sensor. The monitored heat radiation is compared to values in the normal set heat radiation curve by software in the controller. The controller switches the sauna heater off when a deviation from a normal heat radiation curve is detected, and in the absence of a deviation, updates the normal set heat radiation curve with the monitored heat radiation measurements. The system of the invention for identification of objects on a sauna heater comprises a first sensor for the monitoring and a controller. The controller has a memory for storing the radiation curves to be compared. Software in the controller performs the comparison and the updating of the normal set heat radiation curve with the latest heat radiation measurements. The controller has also means for switching the sauna heater off when a deviation from a normal heat radiation curve is detected.