Aircraft Control Lever Linkage for Symmetrical Roll-Pitch Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flight control devices for aircraft face challenges in providing symmetrical force feedback during roll and pitch control, requiring oversized motors and complex servo-controls to decouple forces, which complicates the design and increases operational complexity.
Innovation Solution
A flight control device with a unique configuration of pivot connections and transmission shafts, allowing the control lever to rotate independently around multiple axes without coupling forces, eliminating the need for servo-controls and enabling symmetrical force feedback, and optionally incorporating a redundant passive mechanical emergency system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If control motors with servo control are used to symmetrize force feedback on the control lever, then symmetrical force feedback is achieved, but the device complexity and motor size increase
Solution Approach 1:
The patent replaces the complex servo control system with a purely mechanical linkage system. The control lever is connected through a series of mechanical linkages (first linkage mechanism, first transmission shaft, second linkage mechanism, second transmission shaft) that naturally provide symmetrical force feedback without requiring electronic sensors, controllers, or powered actuators. This mechanical substitution eliminates the need for complex control electronics while achieving the desired symmetrical force characteristics.
Solution Approach 2:
The control system is divided into separate functional segments: the control lever, first linkage mechanism for roll control, second linkage mechanism for pitch control, and transmission shafts. Each segment operates independently with its own pivot joints and axes, allowing the system to achieve decoupled control where roll and pitch movements are mechanically separated. This segmentation enables symmetrical force feedback without requiring complex integrated control systems.
2Ease of operation
If oversized motors are used to ensure symmetrical output force, then symmetrical force feedback is achieved, but the device complexity and size increase
Solution Approach 1:
The patent eliminates the need for oversized motors by replacing the powered control system with a passive mechanical linkage system. The symmetrical force feedback is achieved through the geometric arrangement of pivot joints and linkages rather than through powered actuators. This substitution removes the weight penalty associated with oversized motors while maintaining the desired force characteristics.
Solution Approach 2:
The mechanical linkage system is self-regulating and provides symmetrical force feedback automatically through its geometric configuration. The pivot joints and linkages naturally distribute forces evenly during roll and pitch control without requiring external power sources or active control systems. The system serves itself by using the pilot's input forces directly through the mechanical linkages to achieve balanced force feedback.
3Device complexity
If direct mechanical link between control stick and flight controls is used, then device complexity is reduced, but the control effort becomes uneven during roll and pitch movements
Solution Approach 1:
The patent introduces mechanical segmentation through separate linkage mechanisms for roll and pitch control. The control lever is divided into independent rotational degrees of freedom around different axes, with dedicated linkage mechanisms (first linkage mechanism for roll, second linkage mechanism for pitch) that prevent force coupling between axes. This segmentation maintains relative simplicity while achieving symmetrical control effort characteristics.
Solution Approach 2:
The patent introduces intermediary mechanical elements (linkage mechanisms and transmission shafts with inclined pivot joints) between the control lever and the final control surfaces. These intermediaries decouple the force transmission paths for roll and pitch control, preventing the uneven force distribution that would occur with direct mechanical linkage. The inclined pivot joints act as mediators that redistribute forces to achieve symmetry.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention concerns a device comprising a control lever (8) associated with a frame (1) carrying a first plate (4) linked to the frame, a second plate (10) linked to the first plate (4), the control lever (8) being linked to the second plate (10), a first transmission shaft (12) mounted so as to be able to pivot relative to the frame, a first mechanism linking the control lever to the first transmission shaft such that the rotation of the control lever about the first axis (X) causes the first shaft to rotate about the fourth axis (A), a second transmission shaft (23) mounted so as to be able to pivot relative to the frame, a second mechanism linking the control lever to the second transmission shaft such that the rotation of the control lever about the second axis (Y) causes the second shaft to rotate about the sixth axis (D), a platform (25) linked to the frame, the second linking mechanism being mounted so as to be able to pivot on the platform (25) and being mounted so as to be able to pivot on the control lever (8).