M-ary Time Reversal Pulse Position Modulation for Structural Health Monitoring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Autonomous structural health monitoring of aerostructures using radio frequency (RF) signals interferes with on-board RF communication systems, causing interference and maintenance challenges due to electromagnetic interference and shielding materials.

Innovation Solution

A wireless sensor architecture utilizing elastic waves, specifically Lamb waves, for structural health monitoring, where sensors embedded in the structure use time-reversal pulse position modulation to communicate through the structure itself, avoiding RF signals and mitigating interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If radio frequency signals are used for structural health monitoring, then data communication capability is improved, but electromagnetic interference with on-board communication systems occurs

Engineering Contradiction:

Improvedata communication capabilityVSAvoidelectromagnetic interference

Core Design Contradiction:

Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electromagnetic wave-based RF communication with elastic wave-based structural acoustic communication. Sensors transmit structural health data by generating elastic waves that propagate through the aircraft structure, eliminating electromagnetic radiation and its associated interference with on-board communication systems while maintaining data communication capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The aircraft structure itself serves as an intermediary medium for data transmission. Instead of using RF signals that radiate through space, the structure acts as a waveguide for elastic waves, allowing data to be transmitted through the physical medium of the aircraft body without electromagnetic interference

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If radio frequency signals are used for structural health monitoring, then real-time data processing is improved, but maintenance complexity increases due to shielding requirements

Engineering Contradiction:

Improvereal-time data processing capabilityVSAvoidshielding material requirements

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the requirement for electromagnetic shielding materials from the system. By eliminating RF signals and replacing them with elastic waves, the complex shielding infrastructure needed to prevent electromagnetic interference is completely removed, simplifying the overall system while maintaining real-time data processing capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes electromagnetic field-based communication with mechanical wave-based communication. This replacement eliminates the need for electromagnetic shielding materials and complex RF infrastructure, reducing device complexity while preserving the ability to process structural health data in real-time

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach enables effective structural health monitoring without interfering with aircraft control systems, reduces maintenance costs, and improves data transfer reliability across remote and difficult-to-reach locations by using the structure as a transmission medium for elastic waves.

Implementation Method 1

utilizing at least a portion of the structure as the transmission medium between a sensor and a controller... The structural channel provides a structural medium for the propagation of elastic waves

Methodology Applied

Scientific EffectElastic wave propagation: Elasticity

Implementation Method 2

utilizing a time-reversal based protocol, the detected information using a planar surface of the structure as the transmission medium for elastic waves... A determination is made that is both related to channel probing and responsive to the determination: utilizing one or more time reversal protocols

Methodology Applied

Scientific EffectTime-reversal:

Data Source

PatentUS11362867B2Systems, methods and apparatus for transmission of data using M-ARY time reversal pulse position modulation

Publication Date: 2022.06.14 UNIV OF MARYLAND EASTERN SHORE

AI summary

A system, method and apparatus that includes two or more sensor nodes that obtain sensed data from a structure. A controller receives the sensed data from the sensor nodes, via a network formed by the sensor nodes and the controller. The controller controls functionality of each of the sensor nodes, controls time synchronization among the sensor nodes, detects information collected by the sensor nodes, and communicates, utilizing an M-ary time-reversal based protocol, the detected information using a planar surface of the structure as the transmission medium for elastic waves.