Domestic appliance comprising a differential pressure sensor

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Solution Overview

Problem

Existing door opening aids in household appliances often incorrectly activate due to external pressure fluctuations and inability to distinguish between intentional and accidental door opening attempts, leading to false triggering.

Innovation Solution

A differential pressure sensor monitors pressure curves over a predetermined time interval to detect a pressure profile corridor, activating the door opening aid only when the pressure curve falls within predefined limits, and using a pressure throttle chamber to dampen external fluctuations, ensuring accurate detection of user intent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a differential pressure sensor is used to detect door opening requests, then the door opening aid can be activated to support door opening, but external pressure fluctuations cause false activations

Engineering Contradiction:
Improvedoor opening supportVSAvoidfalse activation rate
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system transitions from static single-pressure-value detection to dynamic pressure profile monitoring over time. The control unit evaluates the temporal development of pressure values to distinguish intentional door opening from accidental pressure fluctuations, thereby reducing false activations while maintaining door opening support functionality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system pre-defines valid pressure profile corridors and evaluation criteria before operation. By establishing predetermined pressure increase thresholds and time-based patterns, the system prepares the decision-making framework in advance, enabling reliable differentiation between intentional and accidental pressure changes without requiring complex real-time analysis.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If a single pressure value is used for detection, then the system is simple, but it cannot distinguish between intentional and accidental door opening attempts

Engineering Contradiction:
Improvedetection system simplicityVSAvoiddoor opening intent detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system adds the time dimension to pressure detection by monitoring pressure profiles over predetermined time intervals. Instead of evaluating a single pressure value, the control unit analyzes the temporal sequence of pressure changes, transforming the detection from a one-dimensional snapshot to a two-dimensional time-pressure profile, thereby enabling accurate intent recognition.

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

Solution Approach 2:

The system pre-defines valid pressure profile corridors and evaluation criteria before operation. By establishing predetermined pressure increase thresholds and time-based patterns, the system prepares the decision-making framework in advance, enabling reliable differentiation between intentional and accidental pressure changes without requiring complex real-time analysis.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the door opening aid is activated frequently, then user convenience is improved, but energy consumption increases

Engineering Contradiction:
Improveuser convenienceVSAvoiddoor opening aid energy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system implements feedback control by continuously monitoring pressure profiles and adjusting door opening aid activation based on detected patterns. By evaluating whether pressure changes match intentional opening profiles, the system provides feedback-driven activation only when needed, avoiding unnecessary energy consumption from frequent activations while maintaining user convenience for legitimate door opening requests.

Inventive Principle:
Principle #23Feedback

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 effectively reduces false activations by considering the shape of the pressure curve rather than individual values, enhancing the reliability of door opening aids and preventing erroneous triggering.

Implementation Method 1

a differential pressure sensor with a sensor membrane for detecting a pressure difference between an internal air pressure in the interior space and an external air pressure in an exterior space

Methodology Applied
Scientific EffectPressure difference detection:

Implementation Method 2

By reducing the external pressure supplied to the differential pressure sensor, such fluctuations can be dampened or reduced

Methodology Applied
Scientific EffectPressure damping: Damping

Data Source

PatentEP3303955B1Domestic appliance comprising a differential pressure sensor
Publication Date: 2019.08.28 BSH HAUSGERATE GMBH
  • EP3303955B1 patent drawingFigure 1
  • EP3303955B1 patent drawingFigure 2
  • EP3303955B1 patent drawingFigure 3

AI summary

The invention relates to a domestic appliance (100) comprising a carcass (101), a door (103) for closing an inner space (105), a differential pressure sensor (106) comprising a sensor membrane (109) for identifying a difference in pressure between an interior air pressure in the inner space (105) and an exterior air pressure in an outer space, a door opening aid (107) for assisting the door opening process, and a control unit for said door opening aid (107) which is dependent on the detected difference in pressure, the control unit being designed to detect a pressure curve (201) of the difference in pressure and to control the door opening aid (107) depending on the pressure curve (201) that has been detected.