Washing Machine Turbidity Sensing for Adaptive Wash Cycle Control
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Solution Overview
Problem
Current washing machines lack an effective method to accurately determine the pollution level of laundry before starting a wash cycle, leading to inefficient use of washing agents and water, and potential under-washing or over-washing due to incorrect initial assumptions about the laundry's dirtiness.
Innovation Solution
The method involves sensing the primary nephelometric turbidity unit (NTU) of washing water before the cycle begins, adjusting the washing time, amount of washing agent, and number of rinses based on the difference between primary and secondary NTU readings, ensuring optimal washing conditions are met.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pollution level of laundry is sensed accurately before washing, then the washing time, amount of washing agent, and number of times of rinsing can be optimized, but the device complexity and measurement requirements increase
Solution Approach 1:
The patent performs preliminary pollution level sensing before the washing cycle starts by measuring NTU of washing water after a brief wetting period. This preliminary measurement allows the system to determine appropriate washing conditions (time, agent amount, rinsing次数) in advance, avoiding the need for complex real-time pollution detection during the washing process.
Solution Approach 2:
The patent implements a feedback mechanism where the primary NTU measurement is compared against reference values, and the washing conditions are adjusted based on this feedback. The system continuously monitors pollution level and modifies washing parameters accordingly, enabling accurate pollution assessment without requiring overly complex sensing hardware.
2Ease of operation
If preset washing conditions are used based on assumed pollution level, then the control process is simple, but washing performance deteriorates when pollution level is inaccurate
Solution Approach 1:
The system performs preliminary pollution level assessment before washing by measuring NTU after a brief wetting period. This allows the control process to remain simple while basing washing condition selection on actual pollution data rather than assumptions, thereby improving washing performance reliability without significantly complicating the control logic.
Solution Approach 2:
The patent dynamically adjusts washing parameters (time, agent amount, rinsing次数) based on the measured pollution level. By changing these parameters according to actual conditions rather than using fixed preset values, the system maintains operational simplicity while ensuring reliable washing performance across different pollution scenarios.
3Reliability
If excessive washing agent and water are used to ensure thorough washing, then washing performance is improved, but resource consumption increases
Solution Approach 1:
The patent performs preliminary pollution level measurement before washing to determine the actual washing needs. Based on this measurement, the system calculates the appropriate amount of washing agent and water required, as well as the necessary washing time and rinsing次数. This prevents both over-washing and under-washing, optimizing resource consumption while ensuring thorough washing when needed.
Solution Approach 2:
The system dynamically adjusts washing parameters including agent amount, water volume, washing time, and rinsing次数 based on the measured pollution level. When pollution is low, these parameters are reduced to minimize resource consumption. When pollution is high, parameters are increased to ensure thorough washing. This adaptive approach eliminates the need to consistently use excessive resources.
4Reliability
If the number of times of rinsing is increased to ensure cleanliness, then washing performance is improved, but washing time is extended
Solution Approach 1:
The patent performs preliminary pollution level assessment to determine the appropriate number of rinsing cycles needed. By measuring NTU before washing and comparing it to reference values, the system can accurately predict how many rinsing cycles will be necessary to achieve the desired cleanliness level, avoiding both unnecessary rinsing and insufficient rinsing.
Solution Approach 2:
The system adjusts the number of rinsing cycles based on the measured pollution level. For lightly soiled laundry, fewer rinsing cycles are performed, reducing washing time. For heavily soiled laundry, more rinsing cycles are performed to ensure thorough cleanliness. This dynamic parameter adjustment optimizes the balance between cleanliness and washing time.
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 accurate determination of the laundry's pollution level, optimizing the use of washing agents and water, reducing consumption, and ensuring thorough washing without excessive cycles or agent usage.
Implementation Method 1
sensing a nephelometric turbidity unit (NTU) of washing water
Data Source
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AI summary
In a control method of a washing machine, a primary nephelometric turbidity unit (NTU) of washing water is sensed (S160) before a washing course is started in a washing cycle, a second NTU is sensed (S160) based on the primary NTU (N1), and a washing time, an amount of washing agent, and/or a number of times (S200, S210, S220) of rinsing are varied based on a difference value between the primary NTU (N1) and the secondary NTU, thereby improving washing performance and washing efficiency.