Sensor device for a household cooling appliance

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Solution Overview

Problem

Existing sensor technologies for household refrigeration appliances are inadequate in accurately determining the opening angle of a pivoting door, particularly for triggering image capture when the door is fully closed, leading to potential inaccuracies in capturing contents within the refrigerator.

Innovation Solution

A sensor device equipped with an inertial sensor, such as a yaw rate sensor, attached to the pivoting door, which integrates yaw rate signals over time to determine the pivoting angle and outputs a signal when a predetermined threshold is reached, ensuring precise detection of the door's closure for optimal image capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a magnetic sensor is used to detect door opening angle, then the detection can be implemented, but the sensor device requires additional components and wiring that complicate the system

Engineering Contradiction:
Improvedoor opening angle detectionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces magnetic sensors and mechanical switches with an inertial sensor that uses motion detection algorithms to determine door state. The processing device calculates door opening angle and closure detection by analyzing acceleration and velocity data from the inertial sensor, eliminating the need for magnetic sensors and complex wiring systems.

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

2Reliability

If the door closure detection is not precise, then the system is simpler, but images may be captured when the door is not fully closed leading to incomplete content visibility

Engineering Contradiction:
Improveimage capture timing accuracyVSAvoidclosure detection mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the processing device continuously monitors door motion parameters (acceleration, velocity, position) from the inertial sensor and adjusts the image capture trigger based on detected door closure events. The system uses the detected door state to control the camera timing, ensuring images are captured only when the door is fully closed.

Inventive Principle:
Principle #23Feedback

3Duration of action of stationary object

If traditional sensors are used, then the system can detect door position, but energy consumption increases and long-term stability decreases

Engineering Contradiction:
Improvesensor operation durationVSAvoidsensor energy consumption
Core Design Contradiction:
Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic sampling of inertial sensor data and uses event-triggered image capture based on detected door closure events. The processing device analyzes motion patterns periodically and only activates the camera when door closure is detected, reducing energy consumption compared to continuous sensor operation or fixed-interval image capture.

Inventive Principle:
Principle #19Periodic action

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

The solution provides precise and reliable detection of the pivoting door's angle, ensuring that images are taken only when the door is fully closed, thereby capturing all contents accurately and efficiently, while minimizing energy consumption and maintaining long-term stability.

Implementation Method 1

The sensor device includes an inertial sensor for providing a movement signal

Methodology Applied
Scientific EffectInertial sensing: Accelerometer

Implementation Method 2

The inertial sensor can include one or more acceleration sensors (translation sensors) and/or one or more yaw rate sensors (rotation sensors)

Methodology Applied
Scientific EffectYaw rate sensing: Gyroscope

Implementation Method 3

The processing device is set up to integrate the yaw rate over time in order to determine the swivel angle

Methodology Applied
Scientific EffectIntegration of angular velocity:

Data Source

PatentEP3662218B1Sensor device for a household cooling appliance
Publication Date: 2021.12.15 BSH HAUSGERATE GMBH
  • EP3662218B1 patent drawingFigure 1
  • EP3662218B1 patent drawingFigure 2
  • EP3662218B1 patent drawingFigure 3

AI summary

A domestic refrigeration appliance (105) comprises a pivotable door (115) on which a sensor device (110) can be mounted. Said sensor device (110) includes an inertial sensor (130) for supplying a motion signal as well as a processing unit (135) configured to determine a pivot angle of the pivotable door (115) on the basis of the motion signal and output a signal when the pivot angle has reached a pre-established limit value.