Laundry Weight Prediction Using a Soft Sensor in Washing Machines

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Solution Overview

Problem

Current laundry treatment appliances lack an accurate and fast method to determine the weight of laundry without using expensive sensors, relying on indirect and time-consuming methods that are not precise, especially for different textile types.

Innovation Solution

A data-driven soft sensor method that predicts laundry weight using supervised learning, utilizing existing sensors to gather operating condition data and training a model to estimate weight based on input parameters such as motor torque, power, and water absorption patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a real weight sensor is used to obtain accurate laundry weight, then measurement precision is improved, but device cost and complexity increase

Engineering Contradiction:
Improvelaundry weight measurement accuracyVSAvoidsensor cost and complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical weight sensor with an electrical measurement system. It uses the electric motor's current consumption and power data to infer laundry weight through software algorithms, eliminating the need for physical weight sensors and their associated costs and complexity.

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

Solution Approach 2:

The patent introduces power consumption data as an intermediary parameter. Instead of measuring weight directly, it measures the electrical power consumed by the motor during drum rotation, which correlates with laundry weight, and uses this intermediate measurement to derive the weight information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If indirect water absorption method is used to estimate laundry weight, then device complexity is reduced, but measurement precision and speed deteriorate

Engineering Contradiction:
Improvesensor simplicityVSAvoidlaundry weight estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the water absorption measurement method with an electrical power measurement approach. By measuring the motor's power consumption during drum rotation, it obtains weight information faster and more accurately without relying on water absorption characteristics of different textiles.

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

Solution Approach 2:

The patent changes the measurement parameter from water absorption (which varies by textile type) to electrical power consumption (which provides consistent correlation with weight). This parameter change enables faster and more accurate weight determination across different laundry compositions.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If indirect water absorption method is used to estimate laundry weight, then device complexity is reduced, but measurement time increases

Engineering Contradiction:
Improvesensor simplicityVSAvoidweight determination time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent replaces the time-consuming water absorption method with instantaneous electrical power measurements. The motor's power consumption can be measured in real-time during drum operation, providing immediate weight information without requiring minutes of water absorption and measurement.

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

Data Source

PatentEP3420127B1Method for the determination of a laundry weight in a laundry treatment appliance
Publication Date: 2023.12.06 ELECTROLUX APPLIANCES
  • EP3420127B1 patent drawingFigure 1
  • EP3420127B1 patent drawingFigure 2
  • EP3420127B1 patent drawingFigure 3

AI summary

The invention relates to a method for the determination of a laundry weight in a laundry treatment appliance comprising: Selecting a laundry program in the laundry treatment appliance; Starting the selected laundry program; Sensing a plurality of parameters indicating operating conditions of the laundry treatment appliance during the laundry program; and Predicting a weight of the laundry present within the laundry treatment appliance based on said plurality of parameters by means of a data-driven soft sensor.