Single Lever Turboprop Control with Torque Scheduling

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Solution Overview

Problem

Turboprop engines traditionally require a dual lever control system, increasing operational complexity and pilot training needs due to disparities with single lever turbofan and turbojet engines, and existing single lever turboprop control systems do not provide a substantially proportional relationship between control lever position and power output.

Innovation Solution

A single lever turboprop control system that utilizes torque-based and/or power-based scheduling to establish a target torque or power output based on the control lever position, adjusting engine parameters like blade angle and rotational speed to achieve a desired proportional relationship between control lever position and power output, incorporating active feedback and limiting functions to adapt to environmental changes and prevent parameter exceedance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a dual lever control system is used for turboprop engines, then the engine can be controlled with separate levers for propeller blade angle and engine rotational speed, but the operational complexity increases and pilot training requirements increase due to disparities with single lever turbofan and turbojet engines

Engineering Contradiction:

Improveease of operationVSAvoidcontrol system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the control of propeller blade angle and engine rotational speed into a single power lever control system. The single lever simultaneously controls both parameters through integrated scheduling logic, eliminating the need for separate levers and reducing operational complexity while maintaining precise engine control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single power lever is designed to perform multiple control functions that traditionally required separate levers. It simultaneously schedules propeller blade angle and engine rotational speed based on a unified control signal, making the control system more versatile and consistent with modern single-lever aircraft engines.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If a single lever control system is used for turboprop engines, then the pilot interface is simplified and consistency with turbofan and turbojet engines is improved, but the relationship between control lever position and power output is not substantially proportional

Engineering Contradiction:

Improvecontrol interface consistencyVSAvoidproportionality between lever position and power output

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The control system employs dynamic scheduling that continuously adjusts the relationship between lever position and engine parameters based on current operating conditions. The scheduling logic dynamically calculates optimal propeller blade angle and engine rotational speed combinations to achieve substantially proportional power output response across the entire lever travel range.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the control parameters from direct mechanical linkage to electronic scheduling with proportional control. The ECU processes the lever position signal and dynamically adjusts engine parameters (rotational speed, blade angle) to maintain a substantially proportional relationship between lever position and power output, compensating for non-linear engine characteristics.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If traditional dual lever control is used, then separate control of propeller blade angle and engine rotational speed is achieved, but additional pilot training is required and familiarity is reduced when transitioning between different engine types

Engineering Contradiction:

Improveengine parameter control capabilityVSAvoidpilot training requirements

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The single power lever control system provides universal control capability for turboprop engines, matching the interface of turbofan and turbojet engines. The lever simultaneously manages propeller blade angle and engine rotational speed through integrated scheduling, creating a universal control paradigm that reduces training requirements across different engine types while maintaining full control functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10773816B2Single lever turboprop control systems and methods utilizing torque-based and power-based scheduling

Publication Date: 2020.09.15 HONEYWELL INTERNATIONAL INC

AI summary

Embodiments of a single lever turboprop control method and system are provided, which utilize torque-based and/or power-based scheduling to achieve a desired (e.g., substantially proportional) relationship between control lever position and the power output of a turboprop engine. In one embodiment, the method includes the step or process of monitoring, at an Engine Control Unit (ECU), for receipt of a Power Lever Angle (PLA) signal from a single lever control device. When a PLA control signal received at the ECU, a target torque or power output is established as a function of at least the PLA control signal. A first engine setpoint, such as a blade angle setpoint or an engine rotational speed setpoint, is determined utilizing the target torque output. An operational parameter of the turboprop engine is then adjusted in accordance with the first engine setpoint.