Variable Return Force Actuator for Angular Position Feedback
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Solution Overview
Problem
Current multidirectional joysticks used in agricultural machines lack sufficient feedback to the user about the angular position of the actuation member relative to the support, as the return force does not vary with the angular position, making it difficult for the user to accurately control the machine.
Innovation Solution
A multidirectional actuator design where the vertical component of the return force varies with the angular position of the actuation member about the vertical axis, utilizing a sliding button with a convex bearing face and grooves that interact with the actuation member to provide distinct resistance levels for different angular positions, allowing the user to feel the angular position through varying resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a spring is mounted compressed between the support and an intermediate button to produce return force, then the return force increases with the angle of inclination of the actuation member, but the return force does not vary according to the angular position of the actuation member about the vertical axis
Solution Approach 1:
The patent applies local quality by creating non-uniform return force characteristics at different angular positions. The return force is made locally stronger or weaker depending on the angular position about the vertical axis, allowing the user to感知 different positions through force feedback. This is achieved through the specific geometric arrangement of the actuation member and support structure that causes the spring compression to vary with angular position.
Solution Approach 2:
The patent implements feedback by making the return force dependent on the angular position of the actuation member. The varying return force provides tactile feedback to the user about the angular position, enabling the user to感知 and control the precise angular position of the actuation member about the vertical axis through force sensations.
2Ease of operation
If the user simultaneously inclines the joystick and the actuation member, then the angular position of the actuation member about the vertical axis cannot be correctly perceived
Solution Approach 1:
The patent resolves this contradiction by providing continuous tactile feedback through varying return force. Even when the joystick is simultaneously inclined, the return force on the actuation member continues to vary with its angular position about the vertical axis, allowing the user to separately感知 and control the angular position through force feedback independent of the joystick's inclination state.
Solution Approach 2:
The patent segments the control feedback by making the return force on the actuation member independent of the joystick's inclination. The actuation member's return force characteristic is separated from the joystick's movement, allowing the user to感知 angular position through the actuation member's force feedback without interference from joystick inclination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances user feedback by providing a perceptible increase in resistance as the actuation member is inclined, enabling more precise control of the machine by allowing the user to differentiate between various angular positions based on the force felt.
Implementation Method 1
The return force is produced by an elastic element, here a spring, that is mounted compressed between the support and an intermediate button
Implementation Method 2
Hall effect sensors that are attached to the support. The measurement means comprise a movable magnet that is attached to the actuation member, and Hall effect sensors that are attached to the support
Data Source
AI summary
The invention proposes a multidirectional actuator (18) comprising:a bottom support (22) with a main vertical axis “A”,a top actuation member (24) that is mounted so as to tilt relative to the bottom support (22) between a central rest position and several actuation positions that are distributed angularly about the vertical axis “A” of the support (22); andmeans (48, 60) of returning the actuation member (24) to its central rest position which exert on the actuation member (24) a return force, whose vertical component is not zero and is oriented upwards, at at least one bearing point “P” situated radially at a distance from the vertical axis “A” of the support (22), characterized in that the value of the vertical component of the return force varies according to the angular position of the actuation member (24) about the vertical axis “A” of the support (22).