Active Blade-Pitch Verification via Motor Torque Analysis

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Solution Overview

Problem

Multi-rotor aircraft with fixed-pitch rotor blades face performance tradeoffs and increased complexity when attempting to transition between hover and forward-flight modes, as they require additional mechanisms for collective pitch changes, which can lead to failures in blade-pitch adjustments without detection methods that do not involve sensors.

Innovation Solution

A method and computer-program product for verifying aircraft flight mode transitions by evaluating motor performance parameters such as motor speed and torque, allowing detection of successful rotor-blade pitch changes without additional hardware, using a process that distinguishes between hover and forward-flight modes based on torque-speed curves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If rotor blade pitch change mechanisms are added to multi-rotor aircraft to enable transition between hover and forward-flight modes, then adaptability to different flight regimes is improved, but device complexity increases

Engineering Contradiction:

Improveadaptability to different flight regimesVSAvoidcomplexity of pitch change mechanisms

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control system uses existing motor performance parameters (speed, torque, power) to self-verify blade pitch changes without external sensors. The system monitors its own operational characteristics to detect pitch transitions, eliminating the need for additional verification hardware and reducing overall system complexity while maintaining adaptability across flight regimes.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent monitors changes in motor performance parameters (speed, torque, power) to detect blade pitch changes. By tracking parameter transitions rather than directly measuring pitch position, the system achieves flight regime adaptability without complex mechanical sensors, resolving the contradiction between versatility and complexity.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If sensors and wiring are added to monitor and verify commanded pitch changes, then measurement precision of pitch status is improved, but device complexity and cost increase

Engineering Contradiction:

Improveprecision of pitch change detectionVSAvoidcomplexity of sensors and wiring

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The control system implements feedback by continuously monitoring motor performance parameters (speed, torque, power) to verify pitch change commands. This closed-loop verification uses existing sensors to measure motor characteristics, providing precise pitch status detection without adding dedicated pitch sensors or complex wiring, thus resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces direct mechanical pitch position sensing with indirect electrical parameter monitoring. By substituting mechanical sensors with analysis of motor electrical characteristics (current, speed, torque), the system achieves precise pitch detection while eliminating complex mechanical sensing systems and associated wiring.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If additional components such as sensors and wiring are added to verify pitch changes, then reliability of pitch verification is improved, but weight increases

Engineering Contradiction:

Improvereliability of pitch verificationVSAvoidweight of verification components

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The control system performs self-verification by monitoring its own motor performance parameters to detect pitch changes. This self-service approach eliminates the need for separate verification sensors and wiring, maintaining reliable pitch change detection while avoiding additional weight from redundant components.

Inventive Principle:

Principle #25Self-service

4Measurement precision

If additional components such as sensors and wiring are added to verify pitch changes, then measurement precision of pitch status is improved, but cost increases

Engineering Contradiction:

Improveprecision of pitch status detectionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive mechanical pitch sensors with cost-effective electrical parameter monitoring. By using existing motor control electronics to measure speed, torque, and power characteristics, the system achieves precise pitch status detection without the high costs associated with dedicated mechanical sensing systems, resolving the contradiction between measurement precision and manufacturing cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11814164B1Active blade-pitch change systems and methods

Publication Date: 2023.11.14 TEXTRON INNOVATIONS INC

AI summary

A method of verifying operation of an aircraft in a pre-defined flight mode includes operating the aircraft in a first flight mode, commanding the aircraft to transition to a second flight mode, evaluating a plurality of motor performance parameters, and based on values of the plurality of motor performance parameters, determining whether the aircraft has successfully transitioned to the second flight mode.