Intrusion Detection with Dynamic Metadata Weighting
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Solution Overview
Problem
Current security systems employing passive infra-red (PIR) and video motion detection (VMD) technologies face challenges with high false alarm rates and reduced detection capability due to adverse conditions like poor lighting, fog, and non-uniform fields of view, leading to poor overall performance.
Innovation Solution
An intrusion detection system that combines outputs from multiple detectors, including PIR and VMD, using metadata to adjust weighting factors and control signals to enhance detection performance, favoring detectors least affected by adverse conditions, and dynamically adjusting sensitivity based on detected parameters like position, speed, and direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a double-knock system combining PIR and VMD detectors is used, then false alarm rejection is improved, but detection capability is reduced
Solution Approach 1:
The patent implements dynamic switching between detection modes (logical AND for false alarm rejection, logical OR for detection capability) based on metadata indicators of adverse conditions. The system transitions from a static double-knock configuration to a dynamic system that adapts its logic operation based on environmental conditions detected by metadata analysis.
Solution Approach 2:
The patent changes the operational parameters of the detection system by switching between different logical operations (AND/OR) based on metadata parameters indicating adverse conditions. This parameter change allows the system to optimize between false alarm rejection and detection capability depending on the operational context.
2Length of moving object
If PIR detector range is extended to detect distant targets, then detection range is improved, but false alarm rate increases due to similar thermal signatures
Solution Approach 1:
The patent introduces VMD as an intermediary detector that works in combination with PIR to distinguish true intrusions from false alarm sources. The VMD provides visual confirmation that helps differentiate between distant thermal signatures that may be false alarms and actual intruders, thereby maintaining extended detection range while reducing false alarm rate.
Solution Approach 2:
The patent merges PIR and VMD detection outputs to compensate for each other's limitations. The combination allows the system to maintain extended PIR detection range while using VMD to filter out false alarms from distant targets with similar thermal signatures, achieving both extended range and reduced false alarm rate.
3Measurement precision
If VMD sensitivity is increased to detect targets with poor contrast, then detection capability is improved, but false alarm rate increases due to detecting non-human movements
Solution Approach 1:
The patent uses PIR detector feedback to validate VMD detections. When VMD detects a target with poor contrast, the system checks for corresponding PIR detection to confirm it is a true intrusion rather than a false alarm from foliage or animals. This feedback mechanism allows high VMD sensitivity while maintaining low false alarm rate through cross-validation.
4Reliability
If detector fields of view are made identical for optimal double-knock configuration, then false alarm rejection is improved, but system complexity and installation difficulty increase
Solution Approach 1:
The patent accepts partial overlap of fields of view rather than requiring exact identity, implementing a relaxed version of the double-knock configuration. This partial action approach maintains sufficient false alarm rejection capability while significantly reducing installation complexity and alignment precision requirements.
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 improves detection performance by reducing false alarms and ensuring detection capability, even under adverse conditions, by leveraging metadata to optimize the combined alarm signal and adjust detector sensitivity dynamically.
Implementation Method 1
passive infra-red (PIR) detection... Detectors including PIR sensors measure the intensity of heat at wavelengths that match those of the heat emitted by warm blooded animals including humans
Implementation Method 2
VMD is performed by computer software on a sequence of digital images captured by a video camera... VMD detects intruders in the sequence by looking for changes in pixel intensities that are consistent with a target moving through the scene
Data Source
AI summary
An intrusion detection system comprises at least two detectors. Each detector is configured to produce a detection output. At least one information module is configured to produce metadata that relates to the performance of one or more of the at least two detectors. An analysis module is configured to produce a combined alarm signal. The combined alarm signal is a function of the plurality of detection outputs from the at least two detectors and the metadata. The metadata may include information relating to adverse conditions that reduce detection performance of one or more of the detectors. The at least two detectors preferably include at least one video motion detector and a passive infrared detector.