Washing Machine Two-Stage Weight Detection for Heavy Load Optimization

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Solution Overview

Problem

Existing washing machines lack an efficient and cost-effective method to quickly determine the weight of laundry, which is crucial for optimizing washing cycles, especially for heavy loads, without increasing production costs or complexity.

Innovation Solution

A method that calculates a first weight of laundry before water supply and compares it to a threshold; if above, a second weight is calculated post-water introduction, adjusting washing cycle parameters independently of the first weight to optimize for heavy loads, using a combination of mechanical sensors and predictive algorithms to minimize data processing and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a weighting scale or complex measurement system is installed to accurately determine laundry weight, then measurement precision is improved, but device complexity and production cost increase

Engineering Contradiction:
Improvelaundry weight measurementVSAvoidwashing machine construction
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical weighing systems with an electrical measurement approach using motor current monitoring. The control unit determines laundry weight by measuring electrical parameters (current, power, torque) of the drive motor during drum rotation, eliminating the need for physical weighing scales and reducing device complexity while maintaining measurement accuracy.

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

Solution Approach 2:

The patent introduces electrical current as an intermediary parameter to indirectly measure laundry weight. Instead of directly weighing the laundry, the system uses the relationship between motor current and drum load to infer weight, providing an accurate measurement method that integrates seamlessly with the existing motor-driven drum mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If accurate laundry weight determination is implemented using complex systems, then washing cycle optimization is improved, but production cost increases

Engineering Contradiction:
Improvewashing cycle optimizationVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent enables the washing machine to self-determine laundry weight using its existing motor and control unit, without requiring external weighing equipment or additional sensors. The system leverages its own operational parameters (motor current, drum rotation) to automatically calculate weight, making the solution cost-effective and easy to manufacture while ensuring reliable washing cycle optimization.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the measurement approach from direct mechanical weight measurement to electrical parameter analysis. By monitoring motor current, power consumption, and torque during drum operation, the system derives laundry weight information from readily available electrical signals, avoiding expensive specialized sensors and simplifying manufacturing.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If continuous monitoring and multiple calculations are performed to determine laundry weight, then measurement accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvelaundry weight determinationVSAvoidenergy for data processing
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary weight determination during the initial drum rotation phase before the main washing cycle begins. The control unit calculates laundry weight based on motor current measurements taken during this early period, allowing subsequent washing parameters to be optimized without requiring continuous monitoring throughout the entire cycle, thus reducing overall energy consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses partial monitoring by measuring motor current at specific intervals and during specific phases of drum operation rather than continuously. This approach provides sufficient accuracy for weight determination while minimizing the energy required for data processing and analysis.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3241938B1Method to control a washing machine
Publication Date: 2019.08.28 ELECTROLUX APPLIANCES
  • EP3241938B1 patent drawingFigure 1
  • EP3241938B1 patent drawingFigure 2
  • EP3241938B1 patent drawingFigure 3

AI summary

The present invention relates to a method to control a washing machine (1), the washing machine including a tub (5) and a drum (6), the drum (6) being rotatably mounted inside the tub (5) and apt to contain laundry to be washed, the method comprising: - setting a washing cycle among a plurality of washing cycles; - calculating a first weight of the laundry in the drum before water is supplied to the drum and/or tub; - comparing the first weight to a first threshold (T1); - if said first weight is above the first threshold (T1), then the method further includes: i. introducing water into the tub; ii. calculating a second weight of the laundry present into the drum; iii. determining a parameter of the set washing cycle on the basis of said second weight, independently from the first weight; iv. washing and/or rinsing said laundry.