Flight Control Surface Actuator Synchronization via Acceleration Limiting

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Solution Overview

Problem

Flight control surfaces experience fatigue due to differences in actuator movement, leading to increased size and weight requirements.

Innovation Solution

A method and system that control actuator displacement by limiting acceleration during an initial period and adjusting actuator status information, using components like acceleration limiters and force fight controllers to synchronize actuator movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple actuators are engaged to the same flight control surface, then the flight control surface can be deployed with redundant actuation, but differences in actuator movement create force fight that causes fatigue

Engineering Contradiction:
Improveredundant actuationVSAvoidfatigue resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The control system receives feedback from each actuator regarding its position and movement status. Based on this feedback, the controller adjusts the displacement commands for each actuator to ensure they move in unison, preventing force fight. The system continuously monitors actuator status and modifies displacement commands dynamically to maintain synchronized operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the displacement parameters of individual actuators based on their status information. By adjusting displacement commands dynamically according to each actuator's performance and position, the system ensures all actuators reach their target positions simultaneously, eliminating force fight while maintaining redundant actuation capability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If actuators are designed to account for force fight fatigue, then reliability is improved, but the actuators and flight control surfaces become bigger and heavier

Engineering Contradiction:
Improvefatigue accountVSAvoidactuator weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

By implementing real-time feedback control that monitors actuator position and movement, the system prevents force fight from occurring in the first place. This eliminates the need to design actuators with excessive weight margins to accommodate force fight fatigue, allowing for lighter actuator design while maintaining reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system takes preliminary action by adjusting actuator displacement commands before force fight can develop. By proactively synchronizing actuator movement based on status feedback, the system prevents the development of damaging forces, allowing actuators to be designed for normal operational loads rather than fatigue-from-force-fight loads.

Inventive Principle:
Principle #10Preliminary action

3Strength

If actuator displacement is controlled during the deployment period, then force fight is reduced, but the deployment time increases

Engineering Contradiction:
Improveforce fight reductionVSAvoiddeployment time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The feedback control system continuously monitors actuator status and makes real-time adjustments to displacement commands. This allows the actuators to move at optimized speeds while maintaining synchronization, reducing force fight without unnecessarily extending deployment time. The system finds the optimal balance between speed and synchronization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts actuator displacement parameters during operation rather than using fixed, conservative timing. By making real-time adjustments based on actual actuator performance, the system optimizes the deployment trajectory to minimize both force fight and deployment time simultaneously.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4707170A2Method and system for deploying a flight control surface
Publication Date: 2026.03.11 BOMBARDIER INC
  • EP4707170A2 patent drawingFigure 1~2
  • EP4707170A2 patent drawingFigure 3
  • EP4707170A2 patent drawingFigure 4

AI summary

A system and method for deploying a flight control surface. The method includes displacing actuators engaged with the flight control surface during an initial period wherein each actuator displaces from zero speed to a deployment speed, and during a deployment period after the initial period. The method includes during the deployment period, controlling displacement of at least one of the actuators in response to actuator status information received therefrom. The method includes during the initial period, limiting an acceleration of said actuator from the zero speed to the deployment speed. The system has a control unit with a force fight controller and an acceleration limiter.