Leading-Edge Actuator Layout for Control Surface Flutter Suppression
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Solution Overview
Problem
Existing aircraft control surface systems face challenges in flutter suppression, particularly with electromechanical actuators, which require complex maintenance and may not be feasible due to hydraulic system limitations, and mass balancing adds unnecessary weight.
Innovation Solution
The actuator is installed at the leading edge of the control surface to optimize mass balance, reducing the need for additional weight and simplifying maintenance by aligning the center of gravity favorably.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If counter-balance weights are added to control surfaces to suppress flutter, then flutter suppression is improved, but weight of the control surface increases
Solution Approach 1:
The actuator and counter-balance weight functions are merged into a single integrated unit. The actuator housing serves as the counter-balance mass, eliminating the need for separate counter-balance weights while maintaining flutter suppression effectiveness.
Solution Approach 2:
The actuator structure performs multiple functions: it provides actuation force to move the control surface and simultaneously serves as the counter-balance mass for flutter suppression. This multi-functional design eliminates redundant components.
2Reliability
If powered hydraulic actuators are used for flutter suppression, then active damping is improved, but device complexity increases due to mode select valves and damping chambers
Solution Approach 1:
The complex valve and damping chamber mechanisms are extracted and removed from the actuator design. Instead, a simplified electromechanical actuator with integrated counter-balance mass is used, achieving passive flutter suppression without the complexity of active damping control systems.
Solution Approach 2:
The hydraulic actuation system with complex valve mechanisms is replaced with an electromechanical actuator system. This substitution eliminates the need for mode select valves, damping chambers, and associated hydraulic control complexity while maintaining actuation capability.
3Reliability
If electromechanical actuators are used as dampers with shortened coils, then active damping is achieved, but manufacturing precision requirements increase due to backlash constraints
Solution Approach 1:
The design accepts the use of standard off-the-shelf electromechanical actuators with typical tolerances rather than custom-designed actuators with tight backlash specifications. The integrated counter-balance mass approach makes the system tolerant of normal manufacturing variations.
Solution Approach 2:
The system transitions from requiring static precision (tight backlash control) to dynamic performance. The actuator operates in a controlled regime where dynamic characteristics and the passive mass balance effect dominate, making the system less sensitive to manufacturing tolerances.
4Reliability
If complex built-in tests are applied to hydraulic actuators to prevent dormant failures, then reliability is improved, but device complexity and maintenance requirements increase
Solution Approach 1:
The hydraulic actuator system with complex built-in test requirements is replaced with a solid-state electromechanical actuator. This substitution eliminates hydraulic leaks, valve failures, and the need for complex built-in test systems, reducing both complexity and maintenance burden.
Solution Approach 2:
The electromechanical actuator with integrated counter-balance mass is inherently more reliable and requires fewer diagnostic and maintenance systems. The passive mass balance design provides inherent stability that reduces the need for complex monitoring and testing infrastructure.
Data Source
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AI summary
Installation of powered actuators in the leading edge of a control surface in order to have a better weight distribution. The systems described herein propose an actuation system with a static ground structure used to move a control surface of an aircraft. The actuation system, and the ground structure are aligned with the center of rotation of the control surface, providing the aircraft with flutter suppression. This proposal is an approach to use the actuator in a place favorable to the mass balancing and reducing or even dismissing the usage of mass balancing, saving weight and cost.