Water level detection system for a washing machine appliance and methods for operating the same
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Solution Overview
Problem
Conventional washing machine appliances with partially blocked pressure sensors in water level detection systems experience erroneous pressure readings, leading to overfilling or underfilling, and typically require maintenance intervention to prevent flooding, rendering the machine inoperable until the blockage is cleared.
Innovation Solution
A method and system for a washing machine that includes a controller to detect a partially blocked pressure sensor, calculate the remaining fill volume needed to reach a target fill volume, and incrementally add water in stages, allowing the pressure sensor to stabilize between additions, thereby avoiding overfilling and maintaining operability until the issue is resolved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the pressure sensor is used to detect water level, then the water level detection is simple and cost-effective, but the sensor may become partially blocked resulting in erroneous pressure readings and delayed response
Solution Approach 1:
The controller detects a partially blocked pressure sensor before it causes complete failure by monitoring for delayed pressure stabilization. When blockage is detected, the system switches to alternative water level detection methods (tub weight, fill time) in advance, preventing flooding and maintaining operational reliability without requiring immediate maintenance intervention.
2Object-affected harmful factors
If the traditional flood prevention state is entered by canceling the cycle and draining all water, then the system is protected from flooding, but the machine becomes inoperable until the blockage is cleared by maintenance
Solution Approach 1:
The system performs self-diagnosis by monitoring pressure sensor response characteristics to detect partial blockages. Instead of requiring maintenance intervention, the controller automatically compensates by using alternative detection methods (tub weight sensing, fill time calculations) to continue operation, maintaining both safety and productivity without shutdown.
Solution Approach 2:
The controller changes the operational parameters by switching from pressure sensor-based water level detection to alternative methods (weight-based detection, time-based fill estimation) when blockage is detected. This parameter change allows the system to maintain accurate water level control and continue operation despite the blocked pressure sensor.
3Productivity
If the pressure sensor readings are not compensated for blockage, then the system operates continuously, but overfilling or underfilling occurs
Solution Approach 1:
The controller continuously monitors the pressure sensor's response characteristics to detect delayed stabilization indicating partial blockage. When blockage is detected, the system switches to alternative feedback mechanisms (tub weight measurements, fill time tracking) to maintain accurate water level control, ensuring both continuous operation and precise water filling.
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 ensures accurate water filling without overfilling the tub, maintaining the machine's functionality until the blockage is addressed, preventing unnecessary shutdowns and allowing for continued operation with improved reliability.
Implementation Method 1
a water level detection system including a pressure sensor for measuring a sump pressure
Data Source
AI summary
A washing machine appliance includes a sump for collecting wash fluid and a water supply valve for supplying the wash fluid during a fill cycle. A controller is configured for detecting when a pressure sensor of a water level detection system is partially blocked and implementing an incremental fill process. Specifically, the controller is configured for determining a remaining fill volume for the wash fluid to reach the target fill volume, opening the supply valve to provide a fraction of the remaining fill volume into the sump and then closing the supply valve, determining that a sump pressure measured by the water level detection system has stabilized, and repeating these steps until a stopping criterion occurs, such as when a fill cycle limit or a target volume is achieved.