Gas Generator Control via Single Throttle Lever and Coefficient Table

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Solution Overview

Problem

Gas turbine engine control systems face interruptions and inefficiencies when transitioning from idle to maximum power, burdening propeller assembly control and increasing manual operation complexity, while existing solutions require significant memory and data storage.

Innovation Solution

A system and method that uses a single throttle lever input to automatically control gas generator and propeller assembly output, scaling the relationship between throttle position and torque/speed output, eliminating manual inputs and optimizing engine performance across the flight envelope, using a controller with a coefficient reference table to reduce memory usage and provide linear variation of power output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple operator manipulated input devices are used to control engine and propeller assembly, then control precision is improved, but device complexity and ease of operation deteriorate

Engineering Contradiction:
Improvecontrol precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple control functions (engine power control and propeller speed control) into a single throttle lever input device. The single lever position simultaneously determines both gas generator output and propeller assembly speed, eliminating the need for separate control devices and reducing overall system complexity while maintaining precise control through unified management.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single throttle lever is designed to perform multiple control functions: it controls both the gas generator power output and the propeller assembly speed. This multi-functional input device replaces what would traditionally require multiple separate controls, simplifying the interface while maintaining comprehensive control capability across the entire propulsion system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple operator manipulated input devices are used to control engine and propeller assembly, then control precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvecontrol precisionVSAvoidease of operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent combines multiple control functions (engine power control and propeller speed control) into a single throttle lever input device. The single lever position simultaneously determines both gas generator output and propeller assembly speed, eliminating the need for separate control devices and reducing overall system complexity while maintaining precise control through unified management.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If manual changes are required for transitions across flight envelope, then adaptability is improved, but ease of operation and productivity deteriorate

Engineering Contradiction:
ImproveadaptabilityVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The control system automatically adapts to different flight conditions and envelopes without requiring manual intervention. The single throttle lever input automatically adjusts engine and propeller parameters based on the current operating regime, allowing the system to self-manage transitions between different flight phases while maintaining optimal performance and adaptability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control system incorporates feedback mechanisms that monitor engine operating conditions and automatically adjust parameters to maintain optimal performance across the flight envelope. This feedback-driven approach enables automatic adaptation to changing flight conditions without requiring manual pilot input for each transition.

Inventive Principle:
Principle #23Feedback

4Reliability

If comprehensive control data is stored in memory, then reliability is improved, but loss of substance (memory usage) worsens

Engineering Contradiction:
ImprovereliabilityVSAvoidmemory usage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent extracts and stores only the essential control parameters and lookup tables in memory, rather than storing comprehensive control data for all possible operating conditions. By identifying and retaining only the critical data elements needed for reliable control, the system achieves sufficient reliability while minimizing memory consumption.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3434598B1Method of controlling gas generator power and torque output
Publication Date: 2021.11.03 GE AVIO SRL
  • EP3434598B1 patent drawingFigure 1
  • EP3434598B1 patent drawingFigure 2
  • EP3434598B1 patent drawingFigure 3

AI summary

The present disclosure is directed to a system for controlling an output of a gas generator via an operator manipulated input device (202). The system includes one or more sensors (246) measuring one or more environmental conditions, a gas generator shaft speed (240), and a power turbine torque (244). The system further includes an operator manipulated input device (202) and one or more controllers including one or more processors and one or more memory devices. The one or more memory devices stores instructions that when executed by the one or more processors cause the one or more processors to perform operations. The operations include receiving, via an operator manipulated input device (202), a throttle lever position defining at least an idle position, a takeoff position, and one or more intermediate positions therebetween; receiving, via one or more sensors (246), one or more environmental conditions, wherein the environmental condition includes one or more of an ambient air temperature, an ambient air pressure, and an ambient airflow rate; determining, via the controller, a first commanded fuel flow of the gas generator based on a gas generator speed output curve (609) based at least on the throttle lever position, the one or more environmental conditions, and a coefficient reference table (218); determining, via the controller, a second commanded fuel flow of the gas generator based on a power turbine torque output curve (220) based at least on the one or more environmental conditions; and generating, via the gas generator, a gas generator output based on the first commanded fuel flow or the second commanded fuel flow.