Refrigerator Ultrasonic Sensor Contamination Detection
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Solution Overview
Problem
Ultrasonic sensors in refrigeration appliances face difficulties in accurately measuring container parameters due to contamination from foreign materials, leading to decreased performance and user frustration with improper auto-fill operations.
Innovation Solution
A system and method utilizing a first and second ultrasonic sensor assembly to detect contamination by comparing the amount of received crosstalk to a threshold value, determining the contamination status based on the comparison, and adjusting the deadband delay to prevent false positives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If ultrasonic sensor assembly is used to monitor container level and initiate auto-fill, then automatic dispensing operation is enabled, but measurement accuracy deteriorates due to contamination from foreign materials
Solution Approach 1:
The system performs preliminary contamination detection by analyzing crosstalk characteristics before contamination significantly degrades measurement accuracy. The controller continuously monitors crosstalk levels and compares them against threshold values, enabling early detection and alerting users to clean the sensor before accuracy is compromised.
Solution Approach 2:
The system implements feedback by continuously monitoring crosstalk characteristics and using this information to determine contamination status. The controller receives crosstalk signals, compares them to threshold values, and generates contamination status indicators that feed back into the dispensing operation, allowing the system to adapt its behavior based on sensor condition.
2Duration of action of stationary object
If ultrasonic sensor operates in contaminated state, then device continues to function, but false positives increase and detection reliability decreases
Solution Approach 1:
The controller continuously monitors crosstalk characteristics and provides feedback on contamination status. By comparing real-time crosstalk measurements against stored threshold values, the system can identify when the sensor is contaminated and adjust its operation or alert the user, maintaining reliable detection despite continued operation in contaminated conditions.
Solution Approach 2:
The crosstalk analysis serves as an intermediary mechanism that indirectly indicates contamination status. Rather than directly measuring contamination, the system uses crosstalk characteristics as a mediator to infer the presence of foreign materials on the sensor surface, enabling reliable detection without direct contact with contaminants.
3Measurement precision
If deadband delay is adjusted to prevent false positives, then detection accuracy improves, but response time may be affected
Solution Approach 1:
The system dynamically adjusts the deadband delay parameter based on contamination status. When contamination is detected through crosstalk analysis, the controller modifies the deadband delay value to compensate for the degraded sensor performance. This parameter adjustment optimizes the balance between preventing false positives and maintaining appropriate response time under varying contamination conditions.
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
Effectively detects contamination in ultrasonic sensor assemblies, preventing false positives and ensuring accurate auto-fill operations by monitoring changes in crosstalk characteristics over time, thereby improving the reliability of the dispensing process.
Implementation Method 1
a first ultrasonic sensor configured to transmit an ultrasonic signal and a second ultrasonic sensor configured to receive the ultrasonic signal
Implementation Method 2
comparing an amount of received crosstalk to a threshold value
Data Source
AI summary
Systems and methods for detecting a contamination status of an ultrasonic sensor assembly included in a refrigeration appliance are provided. An exemplary refrigerator includes a sensor assembly. The sensor assembly includes a first ultrasonic sensor configured to transmit an ultrasonic signal and a second ultrasonic sensor configured to receive the ultrasonic signal. The refrigerator is configured to perform operations comprising detecting whether the sensor assembly is contaminated based on one or more characteristics of the received ultrasonic signal. An exemplary method includes monitoring a change in a characteristic of a plurality of crosstalk components of a plurality of ultrasonic signals of over a period of time to detect a contaminated state of an ultrasonic sensor.