FADEC Base Point Selection via Sensitivity Analysis

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Solution Overview

Problem

Current full authority digital engine control (FADEC) systems for gas turbine engines lack an efficient method to determine optimal base points for controlling engine operations during flight, which affects the accuracy and memory efficiency of engine control.

Innovation Solution

A system and method that involves simulating the gas turbine engine using a model to determine sensitivity ranges of desired engine parameters, dividing the operating envelope into regions, selecting base points within these regions, and performing additional simulations to determine interpolation accuracy, while balancing memory requirements, to generate a base point database for the FADEC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of base points is increased to improve control accuracy, then interpolation accuracy improves, but memory requirements increase

Engineering Contradiction:
Improveinterpolation accuracyVSAvoidmemory requirements
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The operating envelope is divided into multiple regions based on sensitivity analysis of engine parameters. Each region is processed independently to select optimal base points, allowing localized optimization that reduces total base point quantity while maintaining accuracy where it matters most.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different numbers of base points are allocated to different regions of the operating envelope based on their specific sensitivity characteristics. Regions with higher sensitivity to parameter changes receive more base points, while less sensitive regions receive fewer, optimizing the overall balance between accuracy and memory usage.

Inventive Principle:
Principle #3Local quality

2Reliability

If comprehensive base point coverage is provided throughout the operating envelope, then control reliability improves, but device complexity increases

Engineering Contradiction:
Improvecontrol reliabilityVSAvoidbase point database complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Sensitivity analysis and region division are performed in advance during the base point selection process. This preliminary action identifies critical areas requiring detailed base point coverage, allowing the system to pre-determine optimal base point locations that ensure reliability without requiring uniform comprehensive coverage throughout the entire operating envelope.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3451085B1Method for selection of optimal engine operating conditions for generating linearized models for on-board control and estimation
Publication Date: 2020.11.25 RTX CORP
  • EP3451085B1 patent drawingFigure 1
  • EP3451085B1 patent drawingFigure 2
  • EP3451085B1 patent drawingFigure 3

AI summary

A system (200) for generating a base point database (208) for use by a full authority digital engine control (FADEC) to control a gas turbine engine (20) includes a memory (204) configured to store a model of the gas turbine engine. The system also includes a model generation processor (216) coupled to the memory (204) and designed to perform an initial simulation of the gas turbine engine (20) using the model to determine ranges of sensitivity of desired engine parameters throughout an operating envelope (400), divide the operating envelope (400) into a multiple regions (402, 404, 406, 408) based on the ranges of sensitivity of the desired engine parameters, select multiple combinations of base points within each of the multiple regions (402, 404, 406, 408), perform an additional simulation of the gas turbine engine (20) to determine an accuracy of interpolation between each of the multiple combinations of base points for each of the multiple regions (402, 404, 406, 408), and select final base points from the multiple combinations of base points based on the accuracy.