Water level sensing method for a clothes treatment apparatus
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Solution Overview
Problem
Existing water level sensing systems in clothes treatment apparatuses face challenges in accurately determining zero water level due to offset issues that cannot be persistently corrected, leading to measurement inaccuracies.
Innovation Solution
A method for controlling a clothes treatment apparatus that includes a water level sensing system with a chamber having a first pressure chamber communicating with the tub and a second pressure chamber partitioned by an elastic part, allowing for automatic correction of the reference electrical signal by comparing detected signals with a preset range, and using a drainage pump to establish atmospheric pressure, ensuring accurate water level measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a water level sensor is used to measure water level, then water level detection is enabled, but measurement accuracy deteriorates due to offset accumulation over time and external factors
Solution Approach 1:
The system performs preliminary calibration by detecting the electrical signal when the tub is in a known state (empty or full water level) and automatically corrects the reference value before normal measurement operations begin. This preliminary action establishes an accurate baseline that compensates for sensor offset, thereby improving measurement accuracy without requiring manual intervention or sensor replacement.
2Measurement precision
If the water level sensor is replaced with a new one, then initial measurement accuracy is improved, but the problem recurs over time as offset accumulates
Solution Approach 1:
The system continuously monitors the electrical signal from the water level sensor and compares it against dynamically updated reference values. When the tub is in a known state (empty or full), the system detects the actual electrical signal and automatically adjusts the reference value to match, creating a feedback loop that continuously corrects for offset drift. This feedback mechanism maintains measurement accuracy throughout the sensor's operational lifespan, eliminating the need for frequent replacements.
3Measurement precision
If automatic correction of reference value is implemented, then long-term measurement accuracy is maintained, but system complexity increases
Solution Approach 1:
The system performs self-calibration by automatically detecting when the tub is in a known state (empty or full water level) and autonomously correcting its own reference values without external intervention. The controller monitors the electrical signal, compares it with expected values, and adjusts the reference accordingly. This self-service approach maintains sustained measurement accuracy while minimizing the need for complex external calibration equipment or manual adjustment mechanisms.
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
The method effectively secures the accuracy of water level measurement by automatically correcting the reference value, eliminating offset issues and ensuring reliable operation of the water level sensing system.
Implementation Method 1
an elastic part arranged in the chamber that elastically deforms according to change in pressure of the chamber
Implementation Method 2
the output unit comprising a plurality of gauge resistors arranged on one surface of the elastic part
Data Source
Figure 1
Figure 2
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AI summary
Provided is a method for controlling a clothes treatment apparatus comprising: a tub for receiving water; a drum which is rotatably disposed in the tub and receives clothes; a chamber which is in communication with the tub and in which a pressure corresponding to a water level of the tub is formed; an elastic part disposed inside the chamber and elastically deformed according to a change in the pressure of the chamber; an output unit for generating an electrical signal corresponding to the amount of deformation of the elastic part, the output unit including a plurality of gauge resistors disposed on one surface of the elastic part; and a control unit for receiving the electrical signal and comparing the same with a reference electrical signal indicating the state where the tub has a water level of zero, so as to sense the level of water received in the tub. The method comprises: draining water from the tub; detecting an electrical signal from the output unit; comparing the detected electrical signal with a reference electrical signal; and correcting the reference electrical signal when the difference between the reference electrical signal and the detected electrical signal is out of a predetermined first setting range.