Multi-Mode Microwave Waveguide Blade Sensing With Less Wiring

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Solution Overview

Problem

Existing blade measurement systems in aircraft engines face challenges due to increased interconnect counts, which lead to bulky wiring, weight, susceptibility to noise, and potential interconnect failures, limiting sensor placement and accuracy in harsh environments.

Innovation Solution

A multi-mode microwave waveguide blade sensing system utilizing a transceiver, waveguide, and probe sensor to generate and control microwave energy signals in different modes, allowing precise blade position monitoring and improved resolution through selective waveguide modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional wired sensor systems are used to monitor blade parameters, then measurement capability is achieved, but system weight increases and reliability decreases due to extensive cabling and interconnects

Engineering Contradiction:
Improveblade parameter measurementVSAvoidinterconnect failure probability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces traditional wired mechanical/electrical interconnect systems with wireless communication technology. Sensors mounted on blades transmit data via wireless signals to external receivers, eliminating physical cables and connectors that are susceptible to failure in harsh turbine environments. This substitution maintains measurement precision while dramatically improving system reliability by removing vulnerable interconnect points.

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

Solution Approach 2:

The patent extracts the communication function from the mechanical structure by separating the sensing element (mounted on the blade) from the data processing system (located externally). This allows the sensor to operate independently in the harsh turbine environment without requiring physical connections to external systems, thereby improving reliability while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If traditional wired sensor systems are used to monitor blade parameters, then measurement capability is achieved, but system weight increases due to extensive cabling

Engineering Contradiction:
Improveblade parameter measurementVSAvoidcable and connector weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent replaces heavy wired connections with lightweight wireless communication systems. Sensors on the blades communicate data through electromagnetic signals rather than physical cables, eliminating the weight of extensive cabling and connectors that would be required to reach rotating components. This substitution maintains full measurement precision while dramatically reducing system weight.

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

3Measurement precision

If sensors are placed in harsh environments to obtain accurate measurements, then measurement precision improves, but susceptibility to noise and signal degradation increases

Engineering Contradiction:
Improveblade parameter measurementVSAvoidnoise and signal degradation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces wired signal transmission with wireless communication to eliminate the primary sources of noise and interference. By using wireless signals operating in different frequency bands and employing spread-spectrum techniques, the system avoids electromagnetic interference along cable runs and ground loop issues that plague traditional wired sensor systems in harsh turbine environments.

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

Solution Approach 2:

The patent introduces wireless communication as an intermediary medium between the sensors on the blades and the external data processing system. This intermediary transmission method is inherently more resistant to electromagnetic interference and signal degradation compared to direct wired connections, allowing accurate measurements to be obtained from harsh environments without the susceptibility problems of traditional cabling.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If multiple sensors and actuators are installed to improve monitoring capability, then measurement precision improves, but device complexity increases due to wiring requirements

Engineering Contradiction:
Improveblade parameter measurementVSAvoidwiring and connector complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex wired interconnection systems with wireless communication technology. By mounting sensors directly on blades and using wireless transmission to external receivers, the system eliminates the need for complex wiring harnesses, connectors, and routing infrastructure that would be required to support multiple sensors and actuators. This substitution maintains enhanced monitoring capability while dramatically simplifying device complexity.

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

Solution Approach 2:

The patent implements a universal wireless communication platform that can support multiple sensors and actuators simultaneously. Rather than requiring separate wired connections for each device, the wireless system provides a common communication channel that can handle data from numerous sensors and control signals to multiple actuators, thereby reducing overall system complexity while maintaining enhanced monitoring and control capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reduces wiring complexity, weight, and susceptibility to noise, enabling accurate blade measurement and health monitoring with enhanced resolution and reliability in harsh environments.

Implementation Method 1

The transceiver is configured to generate at least one microwave energy signal having a first waveguide mode and a second waveguide mode different from the first waveguide mode

Methodology Applied
Scientific EffectWaveguide mode propagation: Waveguide

Implementation Method 2

The probe sensor includes a proximate end in signal communication with a second end of the waveguide to receive the at least one microwave energy signal and a distal end including an aperture configured to output the at least one microwave energy signal

Methodology Applied
Scientific EffectMicrowave radiation: Microwave Radiation

Implementation Method 3

receives different levels of reflected microwave energy based at least in part on a location at which the at least one microwave energy signal that is directed at the first direction is reflected from the machine compared to a location at which the at least one microwave energy signal that is directed at the second direction is reflected from the machine

Methodology Applied
Scientific EffectElectromagnetic reflection: Reflection

Data Source

PatentEP3978953B1Multi-mode microwave waveguide blade sensing system
Publication Date: 2025.08.27 RTX CORP
  • EP3978953B1 patent drawingFigure 1
  • EP3978953B1 patent drawingFigure 2
  • EP3978953B1 patent drawingFigure 3A~3B

AI summary

A multi-mode microwave waveguide blade sensing system (500) includes a transceiver, a waveguide (174b), and a probe sensor (176). The transceiver generates a microwave energy signal having a first waveguide mode and a different second waveguide mode. The waveguide (174b) includes a first end that receives the microwave energy signal. The probe sensor (176) includes a proximate end (178a) that receives the microwave energy signal from the transceiver and a distal end (178b) including an aperture that outputs the microwave energy signal. The probe sensor (176) directs the microwave energy signal at a first direction based on the first waveguide mode and a different second direction different based on the second waveguide mode. The probe sensor (176) receives different levels of reflected microwave energy based at least in part on a location at which the at least one microwave energy signal is reflected from the machine.