Millimeter-Wave Radar Facial Recognition Anti-Spoofing

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Solution Overview

Problem

Conventional optically-based facial recognition systems are vulnerable to spoofing by photographic images or artificial models, lacking the accuracy and security in identifying biological targets.

Innovation Solution

A millimeter-wave radar-based facial recognition system using multiple sensors to measure depth and reflective properties of facial features, employing machine learning algorithms for feature extraction and comparison to authenticate individuals, preventing spoofing by non-biological targets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optically-based facial recognition systems are used, then the system is simple and cost-effective, but the system is vulnerable to spoofing by photographic images or artificial models

Engineering Contradiction:
Improveauthentication accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces optical-based recognition with radar-based recognition using millimeter-wave signals. The radar system measures physical dimensions and reflective properties of facial features, which cannot be spoofed by photographs or artificial models. This substitution of the sensing mechanism (from optical to radar) fundamentally resolves the vulnerability to spoofing while maintaining system feasibility through the use of available radar technology.

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

Solution Approach 2:

The patent changes the measurement parameters from optical properties (color, texture, appearance) to physical dimensions and RF reflective properties. By measuring depth information, distance to facial features, and reflective characteristics at millimeter-wave frequencies, the system captures parameters that are intrinsic to the biological target and cannot be replicated by non-biological spoofing materials.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If millimeter-wave radar sensors are used to measure multiple sites on the biological target, then the authentication accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvefeature extraction accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the facial recognition task into multiple discrete radar measurements taken at different sites on the face. Each radar sensor or radar beam measures specific facial features (eyes, nose, lips, cheeks) independently. The system then combines these segmented measurements to create a comprehensive target data set, which improves measurement precision while allowing the complex task to be managed through modular measurement approaches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a multi-functional radar system that can perform multiple measurement functions using the same hardware platform. The millimeter-wave radar sensors can measure distance, velocity, depth, and reflective properties, and can target multiple facial sites sequentially or simultaneously. This multi-functionality reduces the need for separate specialized sensors for each measurement type, thereby managing device complexity while achieving high measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If multiple radar sensors are used to perform coherent and non-coherent signal processing, then the reliability of target identification is improved, but the use of energy increases

Engineering Contradiction:
Improvetarget identification accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs dynamic signal processing that adapts between coherent and non-coherent processing modes based on the measurement requirements and target characteristics. The system can switch processing strategies in real-time, using coherent processing when high precision is needed for stationary features and non-coherent processing for moving features or when rapid measurement is required. This dynamic approach optimizes energy consumption while maintaining high reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a hierarchical measurement strategy where not all radar sensors operate at full power simultaneously for all measurements. The system performs preliminary measurements with reduced energy consumption to identify regions of interest, then concentrates full measurement power only on critical facial features that require high-confidence identification. This partial action approach reduces overall energy usage while maintaining sufficient reliability for authentication.

Inventive Principle:
Principle #16Partial or excessive action

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

The system provides secure and accurate identification of biological targets by utilizing millimeter-wave radar sensors to measure physical dimensions and RF reflective properties, enhancing authentication accuracy and preventing spoofing, while being cost-effective compared to other biometric systems.

Implementation Method 1

performing radar measurements for a plurality of sites on the biological target using a millimeter-wave radar sensor

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

receiving a reflection of the frequency modulated signal

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

determining a distance based on a time delay and/or frequency difference between the transmission and reception of the frequency modulated signal

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Data Source

PatentUS11656333B2System and method for identifying a target using radar sensors
Publication Date: 2023.05.23 INFINEON TECHNOLOGIES AG
  • US11656333B2 patent drawing
  • US11656333B2 patent drawing
  • US11656333B2 patent drawing

AI summary

In accordance with an embodiment, a method of recognizing a biological target includes performing radar measurements for a plurality of sites on the biological target using a millimeter-wave radar sensor, producing a target data set for the plurality of sites based on the radar measurements, extracting features from the target data set, comparing the extracted features to stored features, and determining whether the extracted features match the stored features based on the comparing.