Water Level Sensor Method for Wet Washload Property Detection
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Solution Overview
Problem
Existing washing machine technologies fail to accurately identify washload properties, especially when the load is wet, leading to errors in determining dry weight, fabric type, and absorption, and require additional costly components like flow meters, while assuming a dry load at the start of the cycle.
Innovation Solution
The method involves using equilibrium transitions in the washing machine to alter washload wetness and water level, allowing a water level sensor to determine washload properties like dry weight, fabric, and absorption without assuming a dry load, using transitions that occur during normal operation and minimizing testing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If weight detection methods (strain gauge or inertia testing) are used to identify washload properties, then dry weight can be determined, but the method fails when the washload is wet at the start, leading to inaccurate identification
Solution Approach 1:
The patent changes the measurement parameter from weight-based detection to water level-based detection. By measuring the volume of water absorbed by the washload during controlled equilibrium transitions, the system can identify fabric type and dry weight without being affected by initial washload wetness. This parameter change allows accurate measurement regardless of whether the washload starts dry or wet.
Solution Approach 2:
The patent introduces water as an intermediary medium to indirectly measure washload properties. Instead of directly measuring the washload weight or inertia, the system measures the volume of water absorbed by the washload during controlled transitions. This intermediary measurement approach enables accurate identification of dry weight and fabric type even when the washload is initially wet.
2Measurement precision
If absorption measurement methods are used to determine washload composition, then fabric type can be identified, but the method assumes a dry washload at the start and requires additional time for testing
Solution Approach 1:
The patent performs absorption measurement during the initial fill phase of the wash cycle, before the actual washing process begins. By conducting the equilibrium transition tests during this preliminary period, the system identifies washload properties without adding extra time to the wash cycle. The water level sensor continuously monitors absorption during the normal fill operation, eliminating the need for separate testing time.
3Measurement precision
If flow meters are added to accurately measure water added during fill, then absorption measurement accuracy improves, but the cost of the washing machine increases
Solution Approach 1:
The patent replaces the mechanical flow meter with a water level sensor that uses electrical or electronic detection methods. Instead of mechanically measuring water flow, the system measures the water level in the wash tub and calculates absorption based on level changes during controlled equilibrium transitions. This substitution eliminates the need for expensive flow meters while maintaining measurement accuracy.
Solution Approach 2:
The patent uses a simple, inexpensive water level sensor instead of a costly flow meter. The water level sensor is a low-cost component that can accurately detect water level changes, and the system achieves precise absorption measurement through clever use of equilibrium transitions rather than requiring expensive continuous flow measurement hardware.
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 accurately identifies washload properties regardless of initial wetness, reduces costs by eliminating the need for flow meters, and allows for real-time adjustments during wash cycles, providing precise control over wash operations.
Implementation Method 1
measuring the amount of water absorbed by a washload
Implementation Method 2
measuring the inertia of a drum and washload is a more common method employed to determine weight
Data Source
AI summary
A method of identifying the properties of a washload contained in a washing machine based on variations in the output of a water level sensor resulting from transitions that alter the water level in the washer without requiring a change in the volume of water in the washer. Results are independent of the initial wetness of the washload. However initial wetness can also be determined. Variations are at least in part a function of the rate at which the wetness of the washload changes. The rate is nonlinear determined by the composition of the washload. In most transitions the water level is also affected by other factors most of which are at least in part a function of the composition. To simplify the identification preferred transitions occur once the washload wetness has reached equilibrium. To increase accuracy preferably both wetting and dehydrating transitions are used for identification.