Dishwasher Spectral Sensor for Soiling-Adaptive Washing Programs

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Solution Overview

Problem

Universal washing programs in water-using household appliances, such as dishwashers, are often inefficient due to lack of information about specific soiling characteristics, leading to excessive energy and detergent use, as they are not tailored to the individual components of contamination.

Innovation Solution

A device that uses a sensor to detect spectral values of organic compounds in rinse water, determines their functional groups, and adjusts rinsing parameters such as temperature, detergent type, and time based on these groups, allowing for optimized cleaning and resource conservation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a universal washing program is used to cover all potential soiling types, then cleaning reliability is improved, but energy consumption and washing time increase unnecessarily

Engineering Contradiction:
Improvecleaning reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The sensor detects and analyzes soiling characteristics before the washing program begins, allowing the system to pre-determine the optimal washing parameters. This preliminary detection enables the control unit to select an appropriate sub-program tailored to the actual soiling, avoiding unnecessary energy consumption while ensuring reliable cleaning for the present soiling types.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes washing parameters (temperature, time, detergent dosage, water flow) based on the detected soiling characteristics. By adjusting these parameters according to the actual soiling level and type detected by the sensor, the system achieves effective cleaning with optimized resource consumption, resolving the contradiction between cleaning reliability and energy use.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a universal washing program is used to cover all potential soiling types, then cleaning reliability is improved, but washing time increases unnecessarily

Engineering Contradiction:
Improvecleaning reliabilityVSAvoidwashing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The sensor detects and analyzes soiling characteristics before the washing program begins, allowing the system to pre-determine the optimal washing parameters. This preliminary detection enables the control unit to select an appropriate sub-program tailored to the actual soiling, avoiding unnecessary washing time while ensuring reliable cleaning for the present soiling types.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the washing program duration and intensity based on real-time detection of soiling characteristics. By making the washing time adaptive rather than fixed, the system eliminates unnecessary time for lightly soiled items while maintaining sufficient time for heavily soiled items, thus resolving the contradiction between cleaning reliability and washing time.

Inventive Principle:
Principle #15Dynamics

3Reliability

If detergent dosage is increased to ensure cleaning of all potential soiling types, then cleaning effectiveness is improved, but substance consumption increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoiddetergent consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system adjusts detergent dosage as a variable parameter based on the detected soiling characteristics. The sensor identifies the type and amount of soiling present, and the control unit optimizes the detergent dosage accordingly, ensuring effective cleaning for the actual soiling level while minimizing unnecessary detergent consumption for lightly soiled items.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sensor system enables the washing machine to self-determine the appropriate detergent dosage based on its own detection of soiling conditions. This self-service capability allows the system to automatically optimize substance consumption without manual intervention, resolving the contradiction between cleaning effectiveness and detergent usage.

Inventive Principle:
Principle #25Self-service

4Quantity of substance

If turbidity sensors are used to detect soiling, then soiling quantity is detected, but specific characteristics of soiling components remain unknown

Engineering Contradiction:
Improvesoiling quantityVSAvoidsoiling composition information
Core Design Contradiction:
Quantity of substanceVSLoss of information

Solution Approach 1:

The patent replaces simple turbidity sensing with spectral analysis using optical sensors that detect specific wavelengths reflected from soiling. This substitution provides detailed information about soiling composition (organic vs. inorganic, protein-based, starch-based, etc.) rather than just quantity, enabling the control unit to select targeted cleaning approaches for different soiling types.

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

Solution Approach 2:

The system transitions from one-dimensional turbidity measurement to multi-dimensional spectral analysis across different wavelength ranges. By measuring reflectance at multiple wavelengths, the sensor extracts detailed compositional information about the soiling, adding dimensional depth to the detection and resolving the information loss about soiling characteristics.

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

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 enables improved detection and removal of soiling, optimizing cleaning efficiency while reducing resource consumption by tailoring the washing program to the specific nature and quantity of soiling present.

Implementation Method 1

a sensor for detecting spectral measured values of organic compounds in rinse water in the water-conducting household appliance... determining functional groups of the organic compounds based on the detected spectral measured values

Methodology Applied
Scientific EffectNear-infrared spectroscopy: Absorption Spectroscopy

Data Source

PatentEP3509468B1Water-bearing household appliance and method for adapting a rinsing program
Publication Date: 2024.10.09 BSH HAUSGERATE GMBH
  • EP3509468B1 patent drawingFigure 1
  • EP3509468B1 patent drawingFigure 2

AI summary

The invention relates to a device (12) for customizing a washing program to remove soiling on items to be washed in a water-conducting household appliance (1). The device (12) comprises a sensor (13) for acquiring spectral measurement values of organic compounds in the washing water in the water-conducting household appliance (1), a determination unit (14) for determining functional groups of the organic compounds on the basis of the acquired spectral measured values of the organic compounds, and a customization unit (15) for customizing the washing parameters of a current washing program on the basis of the determined functional groups.