Aircraft Rotor Pitch Feedback Device Edge-Effect Mitigation
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Solution Overview
Problem
Existing feedback devices for aircraft propeller systems are vulnerable to 'edge-effects' that increase reading errors as sensors approach the edges, affecting accurate measurement of propeller blade pitch angle.
Innovation Solution
The feedback device features position markers with a high-permeability material coating or plating, applied using procedures like electro-plating or nano-crystalline coating, and a curved concave profile to reduce magnetic flux leakage and enhance sensing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional feedback devices are used without high-permeability material coating, then the device structure remains simple, but reading error increases as sensor approaches edge due to edge-effects
Solution Approach 1:
The patent applies a high-permeability material coating to the position markers, which changes the magnetic permeability parameter of the marker surfaces. This parameter change enhances the magnetic flux distribution and reduces edge-effects, thereby improving reading accuracy without fundamentally altering the device structure
Solution Approach 2:
The patent combines the base position marker material with a high-permeability material coating to create a composite structure. This composite approach leverages the properties of both materials - the structural integrity of the base material and the enhanced magnetic properties of the coating - to reduce reading errors while maintaining device simplicity
2Measurement precision
If position markers lack high-permeability material coating, then manufacturing process remains simple, but magnetic flux leakage increases reducing sensing accuracy
Solution Approach 1:
The patent modifies the magnetic permeability parameter of position markers by applying a high-permeability material coating. This changes the magnetic flux distribution characteristics, reducing leakage and enhancing sensing accuracy. The coating can be applied through established processes like electro-plating or nano-crystalline coating
Solution Approach 2:
The patent replaces reliance on purely mechanical/geometric marker features with a magnetic field-based sensing approach enhanced by high-permeability material. This substitution allows for better flux distribution and reduced edge-effects, improving sensing accuracy while the coating processes used are well-established industrial techniques
3Reliability
If feedback device uses standard material coating, then coating application is straightforward, but edge-effects persist causing reading errors at sensor edges
Solution Approach 1:
The patent specifically selects high-permeability material for the coating, which changes the magnetic properties of the position markers. This parameter change directly addresses edge-effects by improving magnetic flux distribution, thereby reducing reading errors and enhancing reliability
Solution Approach 2:
The patent applies high-permeability material specifically to the position marker surfaces where magnetic flux interaction occurs. This localized application of enhanced material properties targets the specific problem area (edge-effects at marker-sensor interface) without requiring the entire device to be made of complex materials
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 design mitigates edge-effects, improving the accuracy of propeller blade pitch angle measurement and reducing reading errors by maintaining magnetic flux distribution and signal strength.
Implementation Method 1
maintaining magnetic flux distribution and signal strength
Implementation Method 2
position markers with a high-permeability material coating or plating
Implementation Method 3
applied using procedures like electro-plating or nano-crystalline coating
Data Source
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AI summary
A feedback device (400; 600; 650) for use in a gas turbine engine (110), and methods and systems (200) for controlling a pitch for an aircraft-bladed rotor (130), are provided. The feedback device (400; 600; 650) is composed of a circular disk (410) and a plurality of position markers (402). The circular disk (410) is coupled to rotate with a rotor (130) of the gas turbine engine (110), to move along a longitudinal axis (A) of the rotor (130), and has first and second opposing faces (416, 418) defining a root surface (412) that extends between and circumscribes the first and second faces. (416, 418) The plurality of position markers (402) extend radially from the root surface (412) and are circumferentially spaced around the circular disk (410). The position markers (402) have a top surface (404) elevated with respect to the root surface (412) and opposing first and second side surfaces (406, 408). The side surfaces of the position markers (402) have a curved concave profile extending toward the root surface (412).