Rotorcraft Position Validation via GPS Threshold Monitoring

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Solution Overview

Problem

Fly-by-wire systems in rotorcraft face challenges in maintaining accurate position coordinates due to asynchronous communication between GPS receivers and flight computers, leading to potential discontinuities in location data, which can affect the rotorcraft's ability to hold a fixed position, especially in complex flight environments.

Innovation Solution

A method is implemented to monitor the difference between successive GPS location words and discard any that exceed a threshold, ensuring the coarse and fine resolution location words remain synchronized, with the flight control system relying on the most recent accurate location word when discrepancies occur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If asynchronous communication is used between GPS receivers and flight computers to enable independent operation, then system reliability is improved, but position coordinate accuracy deteriorates due to potential mismatches between coarse and fine resolution location words

Engineering Contradiction:
Improvesystem reliabilityVSAvoidposition coordinate accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system continuously monitors the difference between successive GPS location words and compares it against a threshold value. When the difference exceeds the threshold, indicating a potential mismatch between coarse and fine resolution portions, the system generates feedback to invalidate the problematic location data and request new GPS measurements, thereby maintaining position coordinate accuracy while preserving asynchronous communication benefits

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary validation of GPS location data by checking whether the difference between consecutive location readings exceeds a predetermined threshold before accepting the data for flight control use. This preliminary action prevents mismatched coarse and fine resolution location words from corrupting the position coordinate system, ensuring accuracy without requiring synchronous communication

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If GPS location data is continuously updated to maintain accurate position coordinates, then position accuracy is improved, but system stability deteriorates due to potential location word mismatches from asynchronous communication

Engineering Contradiction:
Improveposition coordinate accuracyVSAvoidsystem stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

Before incorporating new GPS location data into the flight control system, the patent performs a preliminary check to determine whether the difference between successive location readings exceeds a threshold value. This preliminary validation prevents unstable or mismatched location word combinations from entering the system, thereby maintaining both accuracy and stability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism that monitors the consistency of successive GPS location readings and compares them against expected thresholds. When instability or mismatches are detected, the system provides feedback to reject the problematic data and request new measurements, ensuring continuous stability while maintaining accurate position coordinates

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3363741B1System and method for validating rotorcraft position coordinates
Publication Date: 2020.03.11 BELL HELICOPTER TEXTRON INC
  • EP3363741B1 patent drawingFigure 1~8
  • EP3363741B1 patent drawingFigure 2
  • EP3363741B1 patent drawingFigure 3

AI summary

In accordance with an embodiment, a method of operating a rotorcraft 101 includes receiving a first sensor value comprising a first coarse resolution portion and a first fine resolution portion, receiving a second sensor value comprising a second coarse resolution portion and a second fine resolution portion, and determining that the second coarse resolution portion corresponds with the second fine resolution portion when a difference between the second sensor value and the first sensor value is within a first threshold.