Washing Machine Load Detection Using Drum Inertia and Water Absorption
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Solution Overview
Problem
Accurately determining the size and type of a load in a washing machine's wash chamber is challenging, leading to inefficient water usage and potential poor cleaning, as existing methods struggle to correlate load characteristics with optimal water volumes.
Innovation Solution
A method that estimates the mass of articles in the wash chamber based on the inertia of the drum and angular velocity, and determines the load type by correlating this mass with the volume of water required to reach a predetermined level, using a controller to adjust drum speed and direct water flow accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed volume of water is directed into the tub regardless of load characteristics, then the washing machine operation is simple, but water is wasted on large loads or loads of highly absorptive articles and insufficient water is provided for small loads or loads of poorly absorptive articles
Solution Approach 1:
The washing machine performs self-diagnosis by automatically detecting load mass through drum inertia measurement and load type through absorption testing, eliminating the need for manual user input or complex external sensors. The system serves itself by using its existing motor and drum as measurement tools.
Solution Approach 2:
The patent replaces complex mechanical load detection mechanisms with electrical measurements of drum rotation characteristics. By measuring angular velocity, acceleration, and deceleration of the drum during motor operation, the system infers load mass without physical contact or additional mechanical sensors.
2Measurement precision
If the volume of water is adjusted to match load size and type accurately, then proper washing is achieved, but determining load characteristics becomes difficult and complex
Solution Approach 1:
The system continuously monitors drum rotation parameters and uses this feedback to calculate load mass. The motor controller measures actual angular velocity and acceleration, compares it with expected values, and adjusts water volume accordingly. This closed-loop feedback enables precise measurement without complex external sensors.
Solution Approach 2:
The patent uses water absorption as an intermediary test to determine load type. By adding a known volume of water and measuring the resulting drum deceleration, the system indirectly infers fabric absorption characteristics without directly analyzing the articles themselves.
3Reliability
If large volumes of water are used for all loads, then all loads receive sufficient water for washing, but water and energy are wasted on small loads and loads of poorly absorptive articles
Solution Approach 1:
The system dynamically adjusts water volume based on real-time load characteristics rather than using fixed volumes. The motor operating parameters change during operation to account for load variations, enabling the system to optimize water delivery for each specific washing scenario.
Solution Approach 2:
The patent changes the parameter of water volume based on detected load mass and type. By calculating the required water volume from measured drum characteristics and fabric absorption properties, the system ensures optimal washing conditions for each load while minimizing water waste.
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 allows for precise determination of load type and size, optimizing water usage and ensuring effective cleaning by adjusting water volumes based on the identified load characteristics, thereby conserving water and energy.
Implementation Method 1
estimating a mass of articles within a wash chamber of a drum based at least in part on an inertia of the drum and articles within the wash chamber of the drum
Implementation Method 2
gauging the mass of articles within the wash chamber of the drum based at least in part on a volume of water within a tub
Data Source
AI summary
A washing machine appliance and a method for operating a washing machine appliance are provided. The method includes estimating a mass of articles within a wash chamber of a drum based at least in part on an inertia of the drum and articles within the wash chamber of the drum, gauging the mass of articles within the wash chamber of the drum based at least in part on a volume of water within a tub, and establishing a load type of articles within the wash chamber of the drum based at least in part on the mass of articles within the wash chamber of the drum from the step of estimating and the mass of articles within the wash chamber of the drum from the step of gauging.