Electronic Propeller Blade Angle Feedback via Singularity Detection

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Solution Overview

Problem

Current turboprop propeller feedback systems, relying on mechanical cam and cables, fail to interface with modern electronic engine control systems, leading to inaccuracies in propeller blade angle measurement and potential serious failure conditions during reverse operation.

Innovation Solution

An electronic beta feedback system utilizing an annular member with singularities and sensors to detect passage and generate signals, allowing for accurate computation of blade angle position, interfacing with existing mechanical systems to provide digital feedback for electronic determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If mechanical cam and cables are used for propeller feedback systems, then the system can provide a variable hydraulic lockout mechanism to prevent propeller transition into low or reverse beta position, but the system cannot interface with modern electronic engine control systems

Engineering Contradiction:
Improveinterface capability with electronic control systemsVSAvoidmechanical cam and cable mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical cam and cable feedback system with an electronic sensing system. A sensor detects the position of an annular member that is mechanically coupled to the propeller blades, and this position information is converted into electronic signals that can be processed by modern electronic engine control systems. This substitution eliminates the need for mechanical interfaces while maintaining the feedback function.

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

Solution Approach 2:

The patent introduces an annular member with singularities as an intermediary element between the mechanical propeller system and the electronic control system. This annular member translates mechanical blade position into detectable positional changes that can be sensed electronically, serving as a bridge between the two different system types.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If mechanical cam and cables are used for propeller feedback systems, then the system can provide blade angle control, but the measurement precision of propeller blade angle is insufficient

Engineering Contradiction:
Improveblade angle measurement accuracyVSAvoidmechanical feedback mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical position sensing with electronic sensing to achieve higher measurement precision. The sensor can detect subtle changes in the annular member's position with greater accuracy than mechanical indicators, providing precise blade angle data to the electronic control system for accurate measurement and control.

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

3Measurement precision

If modern electronic engine control systems are used, then the system can provide accurate power set-point control, but the system lacks interface with propeller feedback mechanisms

Engineering Contradiction:
Improvepower set-point control accuracyVSAvoidinterface compatibility with propeller systems
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent substitutes mechanical feedback interfaces with electronic sensing and signaling, enabling modern electronic engine control systems to receive precise propeller position data. The electronic sensor and signal processing components provide compatibility between electronic control systems and propeller mechanisms, allowing accurate coordinated control of both systems.

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

Solution Approach 2:

The patent changes the feedback parameter from mechanical position indication to electronic position signals. By converting the annular member's mechanical position into electronic signals through sensors, the system enables electronic engine control systems to process propeller position information with high precision, achieving accurate power set-point control.

Inventive Principle:
Principle #35Parameter changes

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

Enables precise measurement and control of propeller blade angles, preventing unintended transitions into low or reverse beta positions, thus ensuring safe and accurate engine operation.

Implementation Method 1

at least one sensor fixedly mounted adjacent an annular member operatively connected to rotate with the propeller... The at least one sensor is configured for successively detecting a passage of each one of the at least two first singularities and the at least one second singularity

Methodology Applied
Scientific EffectMagnetic field sensing: Magnetic Field

Data Source

PatentEP3124377B1System and method for electronic propeller blade angle position feedback
Publication Date: 2018.06.13 PRATT & WHITNEY CANADA CORP
  • EP3124377B1 patent drawingFigure 1
  • EP3124377B1 patent drawingFigure 2
  • EP3124377B1 patent drawingFigure 3

AI summary

A system and method for blade angle position feedback. The system comprises an annular member operatively connected to rotate with a propeller, a sensor fixedly mounted adjacent the annular member and configured for detecting a passage of each singularity as the annular member is rotated and axially displaced and for generating a sensor signal accordingly, the annular member and sensor configured for relative axial displacement between a first relative axial position and a second relative axial position respectively corresponding to the first and the second mode of operation, and a detection unit connected to the sensor for receiving the sensor signal therefrom, determining on the basis of the sensor signal a time interval elapsed between the passage of successive singularities, and computing from the time interval blade angle position.