Jam Tolerant Electromechanical Actuation with Reversible Coupling
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Solution Overview
Problem
Existing electromechanical actuation systems in aircraft and other vehicles are prone to mechanical jams, which can lead to system failure and are not easily testable or reversible, limiting their use in primary flight control applications.
Innovation Solution
A jam-tolerant electromechanical actuation system with a computer-controlled coupling/decoupling mechanism that monitors motor speed, load, and position sensors to detect malfunctions and reversibly disconnect actuators from the load, allowing for continued operation with redundant actuators and enabling reversible disengagement for testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frangible elements or overload mechanisms are used to relieve jams, then jam tolerance is improved, but the system becomes untestable and non-reversible
Solution Approach 1:
The actuation system is divided into multiple independent actuators, each capable of being individually isolated from the load through electrical disconnection. This segmentation allows one actuator to be tested or reset while others remain operational, resolving the contradiction between jam tolerance and testability.
Solution Approach 2:
The patent replaces mechanical jam-relief mechanisms (frangible elements, overload releases) with an electrical disconnection system. This substitution enables reversible isolation of faulty actuators through electrical means, allowing testing and resetting without permanent damage, thus maintaining both jam tolerance and testability.
2Reliability
If mechanical jam relief mechanisms are used, then jam tolerance is improved, but the system complexity increases
Solution Approach 1:
Complex mechanical jam-relief mechanisms are replaced with simpler electrical disconnection systems. The electrical system uses switches and control logic instead of mechanical frangible elements, overload springs, and manual intervention mechanisms, reducing overall system complexity while maintaining jam tolerance.
Solution Approach 2:
The system automatically detects jams through sensor monitoring and independently isolates faulty actuators without requiring manual intervention. This self-service capability eliminates the need for complex manual reset mechanisms and reduces system complexity by automating the jam-relief process.
3Reliability
If overload mechanisms are used to relieve jams, then jam tolerance is improved, but the system cannot be reset without manual intervention
Solution Approach 1:
Manual overload relief mechanisms are replaced with electrical disconnection systems that can be reset through electrical switches. This substitution allows the system to be reset remotely or automatically without manual disassembly or intervention, improving ease of repair while maintaining jam tolerance.
Solution Approach 2:
The system automatically resets isolated actuators by closing electrical switches after jam conditions are resolved, eliminating the need for manual reset procedures. This self-service reset capability simplifies maintenance and improves ease of repair while maintaining reliable jam tolerance.
4Reliability
If multiple actuators are used for redundancy, then reliability is improved, but the device complexity increases
Solution Approach 1:
The system uses multiple independent actuators segmented into separate controllable units. Each actuator can be independently monitored, isolated, and controlled, allowing redundancy without requiring complex interconnections between actuators. This segmentation manages complexity while improving reliability through redundancy.
Solution Approach 2:
Sensor feedback systems monitor each actuator's performance and automatically control isolation switches to manage redundant actuators. This feedback mechanism simplifies the control of multiple actuators by using automated monitoring and switching, reducing the complexity burden of redundancy while maintaining high reliability.
Data Source
AI summary
In a vehicle, having a fixed supporting structure and a load movable relative thereto, a jam tolerant actuating system, a method for controlling this system including: Locating a physical coupling/decoupling mechanism between the load and an actuator assembly as close a practicable to the load; constructing the coupling/uncoupling mechanism to be reversible, and hence testable; and controlling the connection/disconnection via decision making electronics which will detect any system failure by monitoring, at a minimum: actuator main motor load and speed, and actuator output load. Also set forth are specific embodiments of pivotable rotary geared actuators as well as linear ball screw type actuators embodying the coupling/uncoupling mechanisms of this invention.