Passive Optical Vehicle Detection via Light Intensity Fluctuations

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Solution Overview

Problem

Existing drone detection systems are either active and power-intensive, susceptible to interference, or limited in range and accuracy, particularly in detecting small, non-metallic objects like commercial vehicles, and often generate false alarms from birds and other airborne objects.

Innovation Solution

A passive optical camera-based system that uses multiple cameras and imaging processors to detect vehicles by analyzing fluctuations in light intensity from scattered light and reflections, without emitting active signals, allowing for precise identification and tracking of drones and other vehicles without revealing the system's presence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If active detection systems (radar, active RF) are used, then detection range and capability are improved, but power consumption increases and system presence is revealed

Engineering Contradiction:
Improvedetection capabilityVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent inverts the traditional active detection approach by using passive detection - instead of emitting signals and detecting reflections, the system detects fluctuations in ambient light caused by the target. This allows detection without active emissions, reducing power consumption and hiding system presence while maintaining detection capability through sophisticated analysis of scattered light patterns from vehicle rotors and propellers

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces active RF-emitting radar systems with an optical detection system that analyzes light intensity fluctuations. This substitution uses optical sensors and image processing algorithms to detect vehicles through their mechanical rotor/propeller activity, eliminating the need for high-power RF transmitters while achieving comparable or superior detection performance

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

2Use of energy by moving object

If optical techniques relying on motion detection are used, then power consumption is reduced, but false alarms increase from birds and other airborne objects

Engineering Contradiction:
Improvepower consumptionVSAvoidfalse alarm rate
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies local quality analysis by examining specific characteristics of light fluctuations at different spatial and temporal scales. The system analyzes the frequency, amplitude, and spatial distribution of light intensity variations to distinguish between vehicle rotors/propellers and other airborne objects. This localized analysis of fluctuation patterns enables reliable discrimination without increasing false alarm rates

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the detection parameters from simple motion detection to analysis of light intensity fluctuation characteristics. By monitoring frequency spectra, temporal patterns, and spatial distribution of light variations, the system transforms the detection approach to identify vehicles based on their unique rotor/propeller signatures, effectively filtering out birds and other non-vehicle objects

Inventive Principle:
Principle #35Parameter changes

3Length of stationary object

If radar is used to detect vehicles, then detection range is extended, but ability to detect small non-metallic objects deteriorates

Engineering Contradiction:
Improvedetection rangeVSAvoiddetection accuracy for small objects
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The patent replaces radar's RF reflection detection with optical detection of light scattering from vehicle rotors and propellers. This substitution enables detection of small non-metallic objects by capturing the unique light modulation patterns created by rotating blades, achieving both extended range and high precision for small target detection

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

Solution Approach 2:

The patent exploits the mechanical vibration and rotation of vehicle rotors and propellers as the detection mechanism. By detecting the periodic light intensity fluctuations caused by rotating blades interacting with ambient light, the system achieves sensitive detection of small objects at long ranges, overcoming radar's limitation with non-metallic targets

Inventive Principle:
Principle #18Mechanical vibration

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 reliable detection of small vehicles at long ranges, distinguishing them from birds and other airborne objects, with high-definition video imagery and 3D tracking capabilities, while being immune to environmental noise and power consumption issues, and is compact enough for mobile deployment.

Implementation Method 1

detect fluctuations in light intensity from scattered light and/or reflections off of that vehicle

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

detect fluctuations in light intensity from scattered light and/or reflections off of that vehicle

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentUS10403107B2Passive optical detection method and system for vehicles
Publication Date: 2019.09.03 SRI INTERNATIONAL
  • US10403107B2 patent drawing
  • US10403107B2 patent drawing
  • US10403107B2 patent drawing

AI summary

A system, method, and apparatus are discussed for a passive optical camera-based system to detect a presence of one or more vehicles with one or more cameras. A detection algorithm is applied to recognize of the presence of the one or more vehicles using one or more imaging processors and the one or more cameras to detect fluctuations in light intensity from scattered light and/or reflections off of that vehicle. Those scattered light and/or reflections are captured in images contained in a set of frames from the one or more cameras.