Adaptive Flight Control System for Hybrid Helicopter Yaw and Thrust

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing flight control systems for hybrid helicopters face limitations in precision and reliability, particularly in varying the gain applied to flight control commands based on flight conditions, leading to potential mechanical stresses and loss of control authority at high speeds.

Innovation Solution

An adaptive flight control system that modifies the feedback gain applied to flight control commands dynamically based on the current value of the command, using a control means, piloting means, and information feedback means to adjust the pitch of propulsion propeller blades, thereby optimizing control authority and reducing mechanical stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed gain is applied to flight control commands, then the control system is simple to implement, but control precision deteriorates at high speeds

Engineering Contradiction:
Improvecontrol system complexityVSAvoidcontrol precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a dynamic gain adjustment mechanism where the feedback gain varies automatically based on flight conditions (forward speed). The system transitions from a fixed gain structure to a dynamic one that adapts to changing operational parameters, resolving the contradiction between simplicity and precision by making the system structurally dynamic rather than statically simple

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of feedback gain from a constant value to a variable value that depends on forward speed. By making the gain parameter adaptive to flight conditions, the system achieves high control precision across different speed regimes without requiring completely different control systems for each condition

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If high control authority is maintained at all speeds, then control responsiveness is good, but mechanical stresses increase at high speeds

Engineering Contradiction:
Improvecontrol responsivenessVSAvoidmechanical stress
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The patent applies parameter changes by making the feedback gain a function of forward speed. At high speeds, the reduced gain automatically limits control authority, preventing excessive mechanical stresses while maintaining adequate responsiveness. This resolves the contradiction by dynamically adjusting the control parameter rather than maintaining a fixed high-gain setting

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The dynamic gain adjustment creates a speed-dependent control system that automatically modulates control authority. The system transitions from static high-gain control to dynamic gain-scheduled control, ensuring mechanical stress limits are respected at high speeds while preserving control responsiveness when needed

Inventive Principle:
Principle #15Dynamics

3Stress or pressure

If the feedback gain is reduced at high speeds, then mechanical stresses are minimized, but control precision deteriorates

Engineering Contradiction:
Improvemechanical stressVSAvoidcontrol precision
Core Design Contradiction:
Stress or pressureVSMeasurement precision

Solution Approach 1:

The patent resolves this contradiction by making the feedback gain parameter adaptive to forward speed. Rather than simply reducing gain at high speeds, the system optimizes the gain parameter for each speed regime, ensuring adequate control precision is maintained even when mechanical stress constraints require lower gain values at high speeds

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If adaptive gain control is implemented, then control precision is improved, but device complexity increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements adaptive gain control by changing the feedback gain parameter based on forward speed, achieving improved control precision across different flight conditions. The parameter change approach allows the system to maintain relatively simple architecture while gaining adaptive capabilities through intelligent parameter scheduling

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3170744B1An adaptive flight control system for the yaw and thrust flight controls of a hybrid helicopter
Publication Date: 2020.04.01 EUROCOPTER FRANCE SA
  • EP3170744B1 patent drawingFigure 1~2
  • EP3170744B1 patent drawingFigure 3~4
  • EP3170744B1 patent drawingFigure 5~6

AI summary

The present invention relates to an adaptive flight control system (1) for controlling the pitch of the propeller blades of a hybrid helicopter based on the feedback value of said pitch. Said adaptive flight control system (1) comprises a control means (2) providing said pitch command, a piloting element (5) controlling a variation of said pitch, and a piloting means (3) applying a control gain to transform said control command into a setpoint and transmitting said setpoint to said piloting element (5). Said piloting means (3) comprises a feedback means (6) applying a variable feedback gain to said feedback value of said pitch variation to said piloting means (3), also modifying said control gain as a function of said feedback value.