Magnetic Field Threat Detection With Motion Interference Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing personnel inspection systems, such as RF imaging and metal detectors, require divestment of personal items and struggle to distinguish between non-threatening items and potential threats, leading to reduced throughput and usability.
Innovation Solution
A magnetic field-based inspection system that uses singular value decomposition and motion compensation to suppress interference from external sources and motion, allowing for threat detection without item divestment by canceling interference signals and determining the contribution of target magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If RF imaging systems are used for passenger screening, then threat detection capability is improved, but the system requires individuals to remain stationary and divest personal items, reducing throughput and usability
Solution Approach 1:
The patent transitions from stationary RF imaging to a dynamic handheld system that moves with the inspector. The inspection system includes a handheld device with magnetic field sensors that can be moved freely through the inspection zone, allowing continuous scanning of individuals without requiring them to remain stationary. This dynamic approach maintains threat detection capability while significantly improving throughput and usability.
2Measurement precision
If RF imaging systems are used for passenger screening, then threat detection capability is improved, but divestment of personal items is required, reducing usability
Solution Approach 1:
The handheld dynamic inspection system allows inspectors to actively scan individuals and their belongings in place, eliminating the need for divestment procedures. The system's mobility enables thorough inspection of personal items while individuals remain with their belongings, significantly improving usability and ease of operation.
3Measurement precision
If walkthrough metal detectors are used, then metallic object detection is improved, but the system cannot distinguish personal items from threats, requiring divestment and limiting throughput
Solution Approach 1:
The patent employs multiple magnetic field sensors arranged in specific spatial configurations to detect different magnetic signatures. By analyzing the local magnetic field characteristics at multiple points and comparing them against known signatures of personal items versus threats, the system can distinguish between benign metallic objects and dangerous items, eliminating the need for divestment and improving throughput.
Solution Approach 2:
The system measures multiple magnetic field parameters including field strength, direction, and temporal variations as objects pass through the inspection zone. By analyzing changes in these parameters over time and space, the system can differentiate between the magnetic signatures of personal items and threats, enabling discrimination without requiring divestment procedures.
4Adaptability or versatility
If external magnetic fields are present during inspection, then the inspection system can operate in real-world environments, but interference from external sources and motion reduces measurement accuracy
Solution Approach 1:
The patent transforms the harmful effect of external magnetic fields and motion into a useful signal by measuring the induced voltages in the coils. By using the same coils that detect threats to also detect motion-induced signals, and then subtracting these motion components from the total signal, the system effectively removes interference while maintaining the ability to detect threats in real-world environments.
Solution Approach 2:
The system performs preliminary measurements to characterize the background magnetic field and motion-induced signals before conducting the actual threat detection. By establishing a baseline of environmental interference and then subtracting this baseline from the measurement signal, the system preemptively eliminates the harmful effects of external fields and motion, preserving measurement accuracy in versatile operating conditions.
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
Enhances the ability to identify potential threats while maintaining system throughput by suppressing interference from external sources and motion, improving the accuracy and efficiency of threat detection.
Implementation Method 1
walkthrough metal detectors, can include coils to generate and measure changes in a magnetic field caused by magnetic or conductive materials (e.g., metallic) passing through the magnetic field
Implementation Method 2
coils to generate and measure changes in a magnetic field
Data Source
AI summary
A method includes receiving data characterizing a signal obtained by a plurality of magnetic field receivers, the signal formed of a combination of a first magnetic field, a second magnetic field resulting from interaction of the first magnetic field and a first object, and a third signal resulting from motion of receivers within the first magnetic field and/or an external magnetic field other than the first magnetic field. The method also includes determining a component of the signal characterizing a contribution of the second magnetic field to the signal by multiplying the received data by a mapping that characterizes the contributions of the third signal to the signal to cancel the contributions of the third signal. The method further includes providing the determined component of the signal characterizing the contribution of the second field to the signal. Related systems and computer program products are also provided.