Washer Drum Torque Sensing for Pre-Wash Auto-Dosing

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Solution Overview

Problem

Existing laundry appliances with auto-dosing functionality struggle to accurately determine and efficiently deliver the required amount of treatment agents based on the actual laundry load, leading to delayed interaction and partial use of agents during cycles.

Innovation Solution

A laundry appliance with a control unit that uses a predefined speed profile to estimate the laundry load by monitoring motor torques during drum rotation, allowing for timely and precise delivery of treatment agents at the beginning of the cycle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If water absorption method is used to estimate laundry load, then estimate accuracy depends on fabric adsorption degree, but treatment agent delivery is delayed until after estimate completion

Engineering Contradiction:

Improvelaundry load estimate accuracyVSAvoidtreatment agent delivery delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary actions by estimating laundry load using motor torque measurements during drum rotation before water is added and before treatment agent delivery. This allows the treatment agent dose to be determined in advance and delivered immediately at the start of the wash cycle, eliminating delays caused by waiting for water absorption-based estimates to complete.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the water absorption-based estimation method with a mechanical measurement approach using motor torque. By measuring the torque required to rotate the drum at different speeds, the system can determine laundry load mass without relying on fabric adsorption characteristics, enabling faster and more reliable estimation that is independent of fabric type.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If treatment agent dose is released at once after laundry load estimate, then agent interaction with laundry is belated, but if released in distributed manner before estimate completion, then partial amounts are used during some phases

Engineering Contradiction:

Improvelaundry treatment efficiencyVSAvoidtreatment agent interaction timing

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system determines the complete treatment agent dose requirement in advance by estimating laundry load using motor torque measurements before the wash cycle begins. This preliminary determination allows the full required amount of treatment agent to be delivered immediately at the start of the cycle, ensuring optimal interaction from the beginning without the problems of belated or partial delivery.

Inventive Principle:

Principle #10Preliminary action

3Extent of automation

If auto-dosing functionality is implemented, then treatment agent delivery is automated, but amount of agent cannot be adapted to actual laundry load

Engineering Contradiction:

Improvetreatment agent delivery automationVSAvoidtreatment agent dose adaptation to load

Core Design Contradiction:

Extent of automationVSAdaptability or versatility

Solution Approach 1:

The system incorporates feedback by measuring motor torque during drum rotation and using this information to estimate laundry load mass. Based on this estimated load, the control unit automatically adjusts and determines the appropriate treatment agent dose, enabling the auto-dosing functionality to adapt to actual laundry load conditions rather than using fixed predetermined amounts.

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

This approach enables efficient and accurate delivery of treatment agents, improving laundry treatment efficiency by ensuring timely interaction and minimizing agent waste, while also enhancing the reliability of the appliance's operation.

Implementation Method 1

determine an estimate of the amount of laundry load according to one or more parameters of the electric motor being acquired during rotation of the rotatable drum with the predefined speed profile

Methodology Applied

Scientific EffectTorque: Torque

Data Source

PatentUS12006618B2Laundry treatment appliance with dry estimate of the amount of laundry load

Publication Date: 2024.06.11 ELECTROLUX APPLIANCES

AI summary

A laundry treatment appliance having a rotatable drum, an electric motor; at least one compartment to contain multiple doses of treatment agent, and a control unit The control unit is configured to, before delivering water: rotate the drum with a predefined speed profile comprising an accelerating ramp speed profile portion and a constant speed profile portion; estimate the amount of laundry load according to one or more parameters of the electric motor acquired during the drum rotation with the predefined speed profile; and according to said estimate, determine a treatment agent dose to be used during the selected laundry treatment cycle. The control unit is configured to, after determining the treatment agent dose, deliver water to the laundry load, and deliver the determined treatment agent dose to the laundry load.