Single Pixel Thermal Sensor Gesture Recognition via Spatial Modulation

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Solution Overview

Problem

Existing non-imaging gesture recognition technologies are inadequate in detecting multidimensional movements or gestures, lacking the capability to recognize complex patterns and movements effectively.

Innovation Solution

A system utilizing a single pixel thermal sensor with modulating optics that spatially modulates the field of view, enhancing motion signal output and enabling gesture recognition through frequency and amplitude analysis, without the need for imaging sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If non-imaging gesture recognition techniques are used, then device complexity is reduced, but measurement precision of multidimensional movements deteriorates

Engineering Contradiction:
Improvesensor structureVSAvoidgesture detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The field of view is segmented into multiple spatial zones using modulating optics, allowing a single pixel sensor to detect directional information. Each zone corresponds to a specific angular region, enabling the system to determine gesture direction without using multiple sensors or imaging components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds spatial dimension information to the single pixel output by modulating the field of view. The modulating optics create zone-dependent signal modulations that encode angular position information, transforming a one-dimensional pixel output into multi-dimensional gesture recognition capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If single pixel thermal sensor with modulating optics is used, then device complexity is reduced compared to multi-pixel sensors, but the capability to detect multidimensional movements is improved

Engineering Contradiction:
Improvesensor array structureVSAvoidgesture recognition capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The modulating optics divide the field of view into multiple zones with different modulation characteristics. This segmentation allows the single pixel sensor to receive spatially-resolved thermal radiation information, enabling detection of gesture direction and type without requiring multiple sensors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the modulation parameters (frequency and amplitude) of thermal radiation from different spatial zones. By analyzing these parameter variations in the single pixel output signal, the system can distinguish between different gesture types and directions, achieving versatile gesture recognition with a simple sensor.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If imaging techniques with multi-pixel sensors are used, then gesture recognition accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvegesture recognition accuracyVSAvoidoptics and sensor array
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential spatial information needed for gesture recognition from the thermal radiation field, rather than capturing complete images. The modulating optics selectively modulate thermal radiation from different zones, and the single pixel sensor extracts zone-dependent signal characteristics, achieving gesture recognition without full imaging complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using multiple physical sensors to capture spatial information, the system creates a virtual array of sensors through optical modulation. The single pixel sensor receives modulated signals that represent thermal radiation from multiple zones, effectively copying the functionality of a multi-pixel sensor array using a single sensor element.

Inventive Principle:
Principle #26Copying

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

Enables the recognition of gestures by analyzing the frequency and amplitude spectra of the output signal, allowing for the detection of specific motions and gestures such as hand waving or forming geometrical figures, beyond simple presence or motion detection.

Implementation Method 1

a thermal detector with modulating optics. The modulating optics enhances the motion signal output of the thermal detector

Methodology Applied
Scientific EffectThermal radiation detection: Thermal Radiation

Implementation Method 2

The spatial modulation of the FOV of the detector enhances the motion signal output by the detector and may provide a signature

Methodology Applied
Scientific EffectOptical modulation: Lens

Data Source

PatentEP2916199B1Motion and gesture recognition by a passive single pixel thermal sensor system
Publication Date: 2022.05.04 EXCELITAS TECH SINGAPORE PTE LTD
  • EP2916199B1 patent drawingFigure 1
  • EP2916199B1 patent drawingFigure 2
  • EP2916199B1 patent drawingFigure 3

AI summary

Systems and methods for recognizing a gesture made by a warm object are presented. The system includes a thermal sensor configured to generate a low frequency or direct current signal upon receiving thermal energy. A spatially modulating optic is disposed between the thermal sensor and the warm object. The optic is configured to modulate the thermal energy received by the thermal sensor as a function of an orientation of the warm object with respect to the thermal sensor. An electronics unit in communication with the thermal sensor includes a memory and a processor. The processor is configured by the memory to detect a change in the thermal sensor signal and recognize a characteristic of the thermal sensor signal.