Washing Machine Foam Detection at Sticking Speed During Spin-Up
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Solution Overview
Problem
Existing washing machine methods require stopping the laundry drum to detect foam levels during spinning phases, leading to increased cycle duration and energy consumption due to the need for additional unbalancing phases after drum restart.
Innovation Solution
Monitor foam levels while the laundry drum is rotating at a sticking speed, allowing for immediate detection without disrupting the laundry's balance, and initiate a foam-reducing procedure only if necessary, thereby skipping unnecessary unbalancing phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the laundry drum is stopped to detect foam levels during spinning phase, then foam detection can be performed, but the cycle duration and energy consumption increase due to required unbalancing phases
Solution Approach 1:
The patent applies preliminary action by detecting foam levels during the run-up to spin speed phase rather than stopping the drum during the spinning phase. The control unit detects the foam level during the acceleration phase, so that when the drum reaches spinning speed, the foam detection is already complete and no additional stopping or unbalancing phases are needed.
Solution Approach 2:
The patent maintains continuous operation of the laundry drum throughout the process. By detecting foam levels during the run-up phase while the drum is continuously accelerating, the system avoids interruptions and maintains continuous useful action, eliminating the need to stop the drum and perform separate unbalancing phases.
2Measurement precision
If the laundry drum is stopped to detect foam levels, then foam amount can be measured, but energy consumption increases due to additional unbalancing phases
Solution Approach 1:
The patent performs foam level detection during the run-up to spin speed phase before the drum reaches full spinning speed. This preliminary detection eliminates the need for additional stopping and unbalancing phases that would consume extra energy, as the detection is integrated into the existing acceleration process.
Solution Approach 2:
The system maintains continuous drum operation without stopping, eliminating the energy waste associated with repeated acceleration and deceleration cycles. The foam detection occurs during the continuous acceleration phase, avoiding additional energy-consuming unbalancing phases.
3Measurement precision
If the drum is stopped for foam detection, then foam level can be detected, but laundry balance is disrupted requiring additional unbalancing phases
Solution Approach 1:
The patent detects foam levels during the run-up to spin speed phase before the drum reaches full spinning speed. By performing detection during this preliminary phase, the system avoids stopping the drum during spinning, which would disrupt laundry balance and require additional unbalancing phases.
Solution Approach 2:
The drum continues to rotate continuously during foam detection without stopping, maintaining the laundry's balanced state. The detection occurs during the natural acceleration phase, so no interruptions occur that would disrupt laundry distribution or require corrective unbalancing phases.
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 reduces the overall time and energy consumption of the washing cycle by maintaining the laundry's balanced state during foam monitoring and eliminating the need for additional unbalancing phases.
Implementation Method 1
rotating at a sticking speed at which laundry clings at an inner periphery of the laundry drum
Data Source
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AI summary
The present invention relates to a method for operating a washing machine (10) adapted to perform a washing cycle and comprising a washing tub (24) in which a laundry drum (26) is contained, said method comprises the steps of: - rotating said laundry drum (26) at a sticking speed (vst) at which laundry (28) clings at an inner periphery of said laundry drum (26), - detecting a liquid level (44) in a washing tub (24) and/or in a draining region thereof while said laundry drum (26) is rotating at said sticking speed (vst), and - starting a foam-reducing procedure if the detected liquid level (44) corresponds to a prefixed value or is within a prefixed range of values, or if the time dependent behaviour of said the detected liquid level (44) corresponds to a prefixed time dependent behaviour.