FMCW Radar Occupant Detection Using Time-Velocity Feature Extraction

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Solution Overview

Problem

Existing technologies struggle to accurately detect the presence and position of occupants within partially enclosed spaces, such as vehicles, using radio waves, particularly for applications in self-driving vehicles and other environments where precise human detection is necessary.

Innovation Solution

An electronic device equipped with a signal processing unit that processes transmission and reflected radio waves to extract two-dimensional data, including time and velocity directions, to determine the presence and position of humans or objects, utilizing frequency-modulated continuous-wave radar (FMCW) technology and advanced signal processing techniques like fast Fourier transforms and angle-of-arrival estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If radar technology is used to detect occupants in enclosed spaces, then detection capability is improved, but accuracy in determining presence and position deteriorates

Engineering Contradiction:
Improvedetection capabilityVSAvoidaccuracy in determining presence and position
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent transforms one-dimensional radar detection data into two-dimensional data by extracting both time direction information (distance) and velocity direction information (movement state) to determine occupancy. This dimensional expansion enables more accurate identification of human presence and position by analyzing patterns across multiple dimensions simultaneously.

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

Solution Approach 2:

The patent employs periodic radar signal transmission and receives reflected waves over prescribed time intervals to detect human occupants. By periodically measuring distance and velocity information and analyzing changes over time, the system can distinguish between stationary objects and moving human occupants, thereby improving detection accuracy in enclosed spaces.

Inventive Principle:
Principle #19Periodic action

2Device complexity

If simple radar detection is used, then device complexity is reduced, but detection accuracy in enclosed spaces deteriorates

Engineering Contradiction:
Improvesystem simplicityVSAvoidoccupant detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent enhances a conventional radar system by extracting two-dimensional data (time direction and velocity direction) from radar signals. This additional dimensional analysis enables accurate occupancy detection without requiring fundamentally different hardware, thus improving precision while maintaining relative system simplicity.

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

Solution Approach 2:

The patent improves detection accuracy by analyzing multiple parameters from radar signals including distance (time of flight), velocity (Doppler shift), and temporal patterns. By monitoring changes in these parameters over prescribed time intervals, the system can reliably distinguish human occupants from other objects in enclosed spaces using existing radar technology.

Inventive Principle:
Principle #35Parameter changes

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 accurate detection of human presence and position within enclosed spaces, enhancing safety and functionality in self-driving vehicles and other environments by providing precise occupancy information.

Implementation Method 1

a received signal received as a reflected wave resulting from the transmission wave being reflected by the object

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

two-dimensional data having a time direction and a velocity direction that correspond to a distance between the electronic device and the human body

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 3

two-dimensional data having a time direction and a velocity direction

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4679130A1Electronic device, method for controlling electronic device, and program
Publication Date: 2026.01.14 KYOCERA CORP
  • EP4679130A1 patent drawingFigure 1
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AI summary

An electronic device is provided with a signal processing unit. The signal processing unit is configured to detect an object on the basis of a transmission signal transmitted as a transmission wave and a received signal received as a reflected wave resulting from the transmission wave being reflected by the object. The signal processing unit is configured to extract, from a result of estimating an angle, with respect to the electronic device, of a human body to be detected on the basis of the transmission signal and the received signal over a prescribed time, two-dimensional data having a time direction and a velocity direction that correspond to a distance between the electronic device and the human body, and extract a prescribed feature on the basis of the two-dimensional data.