Aircraft Joystick Mechanical Linkage for Decoupled Restoring Forces
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Solution Overview
Problem
Existing mini-stick mechanical structures for aircraft piloting do not allow for decoupling of restoring forces between the roll and pitch axes, and cannot generate linear restoring forces proportional to the angular position of the joystick.
Innovation Solution
A mini-stick design featuring a frame with a handle that rotates around multiple axes, including a fifth axis allowing misalignment between the primary axes of rotation, enabling independent control of restoring forces and linear force feedback through a mechanical assembly with rotatable connecting parts, cradles, and return members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional mini-stick mechanical structure is used, then the device is compact and integrates into the armrest, but the restoring forces between the two axes of rotation are coupled and cannot be independently controlled
Solution Approach 1:
The mechanical connection assembly is divided into multiple independent components: a first connecting part for the roll axis, a second connecting part for the pitch axis, and a third intermediate part that connects them. Each connecting part has its own restoring force mechanism, allowing independent control of forces on each axis while maintaining overall structural integration.
2Manufacturing precision
If existing mini-stick structures are used, then the space between pilot and dashboard is freed up, but linear restoring forces proportional to angular position cannot be generated
Solution Approach 1:
The mechanism incorporates a variable ratio between angular displacement and restoring force through the geometric relationship between the connecting parts and intermediate part. As the handle rotates around the first axis, the intermediate part's position changes, modifying the effective lever arm and spring engagement, thereby generating a restoring force that is linearly proportional to the angular position rather than simply proportional to the rotation angle.
3Adaptability or versatility
If the second axis of rotation is perpendicular to the first axis, then the control geometry is simplified, but misalignment between fixed frame axes and pivoting reference frame axes cannot be accommodated
Solution Approach 1:
The third intermediate part acts as a mediator between the first connecting part (roll axis) and the second connecting part (pitch axis). It contains a second spherical joint that allows relative misalignment between the two axes while transmitting forces and movements between them. This intermediate element absorbs the geometric incompatibility between the fixed frame reference and the pivoting reference frames, enabling the mechanism to function with non-perpendicular or misaligned axes.
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
The invention relates to a joystick (200) for controlling an aircraft, including a frame (201), a lever (202) mounted so as to be rotatably movable relative to the frame, and a mechanical linking assembly (203) for connecting the lever to the frame, the mechanical linking assembly (203) including: a first linking piece (213, 223) movably mounted relative to the frame (201) about a first rotation axis (X), a second linking piece (233, 243) movably mounted relative to the frame (201) about a second rotation axis (Y), the second rotation axis forming a non-zero angle with the first rotation axis, a third intermediate piece (255, 265) mounted so as to be rotatably movable relative to the first linking piece (213, 223) about a third rotation axis (Y'), a fourth intermediate piece (275, 285) mounted so as to be rotatably movable relative to the second linking piece (233, 243) about a fourth rotation axis (X'), the fourth rotation axis forming a non-zero angle with the third rotation axis, in which the linking pieces (213, 223; 233, 243) or the intermediate pieces (255, 265;275, 285) are rotatably movable in relation to one another about a fifth rotation axis (Z') forming a non-zero angle with the first rotation axis (X) and the second rotation axis (Y) or with the third rotation axis (Y') and the fourth rotation axis (X'), respectively, so as to enable a variation of the angle formed between the first rotation axis and the second rotation axis or of the angle formed between the third rotation axis and the fourth rotation axis, respectively.