Washing Machine Detergent Type Detection Using Conductivity Sensing

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Solution Overview

Problem

Current washing machines lack the ability to automatically detect and supply the appropriate type of detergent based on the laundry type, leading to suboptimal washing results when a preset detergent is not used, as existing technologies only detect detergent levels without identifying the type.

Innovation Solution

A washing machine equipped with a detergent supply device that includes multiple cartridges, an electrode sensor to detect the conductivity of additives, and a controller that determines the type of detergent by comparing detected values with stored data, allowing for automatic selection and input of suitable additives based on the washing course.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only a detergent sensor is installed to detect the amount of detergent, then the device complexity is reduced, but the ability to detect the type of detergent is lost

Engineering Contradiction:
Improvedetection system complexityVSAvoiddetergent type information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

An electrode sensor is introduced as an intermediary detection device between the detergent container and the control system. The electrode sensor measures the conductivity of the detergent liquid, which serves as a characteristic signature to identify the detergent type. This intermediary measurement enables type detection without requiring complex spectroscopic or chemical analysis systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces potential complex mechanical or optical detection systems with an electrical measurement approach. By using an electrode sensor to measure conductivity, the system substitutes simpler electrical measurement technology for more complex alternatives, achieving detergent type identification through electrical properties rather than mechanical or optical methods.

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

2Measurement precision

If the user must preset detergent in each container, then the measurement precision of detergent type is improved, but the ease of operation deteriorates

Engineering Contradiction:
Improvedetergent type identification accuracyVSAvoiduser input requirement
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs self-identification of detergent types by automatically measuring the conductivity of the liquid in each container using the electrode sensor. The control system compares the measured conductivity values against stored reference data to automatically determine which detergent is present in each container, eliminating the need for users to manually preset or label detergent types while maintaining accurate identification.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system establishes a feedback loop where the electrode sensor continuously monitors detergent conductivity, the control system processes this data by comparing it with stored reference values, and the results are used to automatically control detergent dispensing. This closed-loop feedback mechanism ensures accurate detergent type identification and appropriate dispensing control without requiring user intervention.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If various types of detergents are automatically mixed and supplied, then the adaptability to different laundry types is improved, but the device complexity increases

Engineering Contradiction:
Improvedetergent selection capabilityVSAvoiddetergent supply system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system utilizes changes in electrical conductivity as a key parameter to differentiate between various detergent types. By measuring and comparing conductivity values against stored reference data, the system can identify and adapt to different detergent formulations. This parameter-based approach enables versatile detergent selection while avoiding the need for complex multi-sensor systems or sophisticated analysis equipment.

Inventive Principle:
Principle #35Parameter changes

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

Ensures the appropriate detergent is automatically selected and input for the washing process, even if a user does not pre-select it, enhancing washing efficiency and effectiveness by matching detergent type with the specific laundry requirements.

Implementation Method 1

a sensor which detects a type of additive contained in the plurality of cartridges... The sensor may be an electrode sensor that detects the conductivity of the additive

Methodology Applied
Scientific EffectConductivity detection: Conduction (electrical)

Data Source

PatentEP3722484B1Washing machine and control method of same
Publication Date: 2022.03.16 LG ELECTRONICS INC
  • EP3722484B1 patent drawingFigure 1
  • EP3722484B1 patent drawingFigure 2
  • EP3722484B1 patent drawingFigure 3

AI summary

The present disclosure relates to a washing machine and a control method of the same. The washing machine including: a detergent supply device which supplies a liquid additive (S160, S40) to the tub (31); and a controller (3) which controls the operation of the detergent supply device. The detergent supply device includes: a plurality of cartridges (200A, 200) which contain the additive (S160, S40) respectively; an electrode sensor (300A, 300) which detects conductivity of the additive (S160, S40) contained in the plurality of cartridges (200A, 200); and a pump (500, S150) which extracts the additive (S160, S40) contained in the cartridge (200A, 200, 220), and the controller (3) determines a type of additive (S160, S40) contained in the cartridge (200A, 200, 220) based on a detection value of the electrode sensor (300A, 300).