Fiber Optic Strap Tamper Detection with Dirt Compensation

Solution Overview

Problem

Body-worn devices used for tracking individuals on house arrest face issues with false tampering alerts due to dirt and humidity accumulation in fiber optic connections, which can degrade the signal and lead to incorrect tampering detection.

Innovation Solution

A system that embeds a fiber optic cable within the strap of the body-worn device, using a light source and sensor to monitor light pulses and adjust intensity to compensate for degradation caused by dirt and wear, thereby distinguishing between tampering and normal degradation, and generating alerts for maintenance or replacement as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fiber optic cable is used for tamper detection, then tamper detection reliability is improved, but false alarms occur due to dirt and humidity accumulation

Engineering Contradiction:

Improvetamper detection reliabilityVSAvoidsignal accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the light source intensity based on the received signal strength. The controller monitors the light signal received by the sensor and automatically increases or decreases the light source output to maintain optimal signal levels, compensating for dirt accumulation and humidity effects in real-time.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the light source, specifically its intensity, to compensate for environmental degradation. By adjusting the light intensity parameter, the system maintains reliable tamper detection despite dirt and humidity accumulation in the fiber optic connection.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If light source intensity is increased to compensate for degradation, then signal strength is improved, but energy consumption increases

Engineering Contradiction:

Improvesignal strengthVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the light source intensity based on the received signal strength. The controller monitors the light signal received by the sensor and automatically increases or decreases the light source output to maintain optimal signal levels, compensating for dirt accumulation and humidity effects in real-time.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the light sensor to control the light source intensity. The controller receives information about the received signal strength and adjusts the light source accordingly, creating a closed-loop control system that optimizes energy consumption while maintaining reliable signal transmission.

Inventive Principle:

Principle #23Feedback

3Reliability

If the body-worn device is worn continuously, then tracking reliability is improved, but dirt and humidity accumulation increases

Engineering Contradiction:

Improvetracking reliabilityVSAvoiddirt and humidity accumulation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system converts the harmful effect of dirt and humidity accumulation into a measurable parameter. By monitoring the light signal degradation caused by these factors, the system can compensate for their effects and even alert users when cleaning is needed, turning a problematic condition into useful information.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system dynamically adjusts the light source intensity based on the received signal strength. The controller monitors the light signal received by the sensor and automatically increases or decreases the light source output to maintain optimal signal levels, compensating for dirt accumulation and humidity effects in real-time.

Inventive Principle:

Principle #15Dynamics

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 effectively differentiates between tampering and normal degradation, reducing false alarms and ensuring accurate tracking while allowing for the secure and reliable operation of the body-worn device.

Implementation Method 1

A light source emits light through an optical interface and into the fiber optic cable and a light sensor receives light from the fiber optic cable through another optical interface

Methodology Applied

Scientific EffectLight emission and detection: Light

Implementation Method 2

A fiber optic cable is embedded within the strap and there is an optical interface through which light can be injected into and monitored from the fiber optic cable

Methodology Applied

Scientific EffectOptical signal transmission: Optical Fibre

Data Source

PatentUS11169096B1Body-worn device with tamper detection, dirt alerting and dirt compensation

Publication Date: 2021.11.09 DETECTION INNOVATION GRP INC

AI summary

A system and method for detecting degradation of a fiber optic in a strap of a body-worn device that is removably attached to an appendage or other location of a person or animal. A fiber optic is embedded within the strap. A light source emits light energy through the optical interface and into the fiber optic and a light sensor receives and detects light energy from the fiber optic. If the light energy is not received and detected from the fiber optic, the light energy is increased until the light energy is received and detected or reaches a maximum light energy at which time tampering is declared. If the light energy reaches a pre-determined threshold which is less than the maximum light energy, it is declared that the body-worn device requires servicing.