Cooktop Boil Detection Using Motion Vector Histograms

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Solution Overview

Problem

Existing boil detection systems, such as motion sensors and temperature sensors, suffer from inaccuracies and false positives, leading to issues like overcooking, splattering, and potential fires due to incomplete heat reduction during boiling events.

Innovation Solution

A computer vision algorithm is applied to imagery from a camera positioned above the cooktop to detect boiling events by calculating dissimilarity scores between motion vectors in consecutive frames and pre-learned histograms, accurately distinguishing between boiling and non-boiling states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If motion sensors are used to detect boiling events, then the system can detect motion at the cooktop, but human motion or rising steam triggers false positives

Engineering Contradiction:
Improveboil detection accuracyVSAvoidfalse positive rate
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system segments the motion detection task by analyzing individual pixel changes and organizing them into motion vectors, then further segments the analysis by creating histograms of motion characteristics. This granular segmentation allows the system to distinguish between the specific motion patterns of boiling liquid and other motions like steam or human activity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies the principle of color changes metaphorically by transforming visual information into a different representation space - converting image frames into motion vector histograms. This transformation allows the system to detect boiling by comparing histogram characteristics rather than raw visual patterns, effectively distinguishing boiling from false positives.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If temperature sensors are used to detect boiling events, then the system can measure temperature at the cooktop, but the generally heated environment causes significant measurement errors

Engineering Contradiction:
Improveboiling detection precisionVSAvoidmeasurement accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system replaces the thermal measurement approach with a visual motion analysis approach. Instead of using temperature sensors that struggle in heated environments, the system uses a camera to capture visual motion patterns and analyzes them through histogram comparison. This substitution of measurement modality eliminates the interference from the generally heated environment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the measurement parameter from temperature to motion characteristics. By detecting boiling through motion patterns in video frames rather than temperature readings, the system avoids the problem of temperature sensors being unable to distinguish boiling temperature from the generally heated cooktop environment.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a camera and computer vision algorithm are used to detect boiling events, then the system can accurately distinguish boiling from non-boiling states, but the device complexity increases

Engineering Contradiction:
Improveboil detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system extracts only the essential features needed for boil detection - motion vectors and their histogram characteristics - from the full video frames. By taking out and analyzing only these relevant features rather than processing entire images, the system achieves high accuracy while managing computational complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary action by pre-learning and storing histograms of boiling liquid characteristics before actual detection. During operation, it simply compares current motion histograms against these pre-established templates, avoiding the need for complex real-time analysis and reducing computational complexity while maintaining high reliability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS9330469B2Systems and methods for boil detection
Publication Date: 2016.05.03 HAIER US APPLIANCE SOLUTIONS INC
  • US9330469B2 patent drawing
  • US9330469B2 patent drawing
  • US9330469B2 patent drawing

AI summary

Systems and methods for boil detection are provided. One example system includes a vision sensor positioned to collect imagery depicting the cooktop and one or more processors implementing instructions to perform operations. The operations include obtaining a first frame of imagery and a second frame of imagery from the vision sensor. The first frame of imagery and the second frame of imagery respectively depict the cooktop. The operations include identifying a plurality of motion vectors based on the first and second frames of imagery. The operations include generating a histogram describing a characteristic of the plurality of motion vectors. The operations include calculating a dissimilarity score. The dissimilarity score describes a difference between the histogram and a pre-learned histogram. The pre-learned histogram describes the characteristic for imagery depicting boiling liquid. The operations include determining whether a boiling event is occurring at the cooktop based at least in part on the dissimilarity score.