Inductive Joystick Position Sensing to Prevent Drift and Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Joysticks using potentiometers suffer from component tolerance variations and short lifespans due to wear and tear, leading to inaccurate position determination and joystick drifting.
Innovation Solution
An inductive joystick with a control structure and a position sensing assembly that includes a printed circuit board with transmitter and receiver coils, and metal dials that interfere with the induction signal, allowing for contactless sensing and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If potentiometers are used for position sensing, then the joystick can detect mid rod movement, but component tolerance variations cause inaccurate position determination
Solution Approach 1:
The patent replaces the mechanical contact-based potentiometer system with an inductive sensing system using coils and a movable core. This eliminates direct mechanical contact between sensing components, removing the source of component tolerance variations and wear. The inductive principle uses magnetic field coupling to detect position, providing more stable and accurate measurements over time.
Solution Approach 2:
The patent introduces a movable core as an intermediary element that couples the mechanical movement to the inductive sensing field. The core modifies the magnetic field distribution in response to mid rod position, allowing indirect sensing that avoids direct contact between the sensing coils and moving parts, thereby eliminating wear and tolerance issues.
2Duration of action of moving object
If carbon resistive elements are used in potentiometers, then the joystick can operate, but frequent contact causes wear and tear leading to short lifespan
Solution Approach 1:
The patent replaces the mechanical contact system with an inductive sensing mechanism that uses magnetic field interaction instead of physical contact. The coils generate and detect changes in magnetic flux through the movable core, eliminating the need for sliding contacts and carbon resistive elements that are subject to abrasion and wear.
Solution Approach 2:
The patent extracts and removes the carbon resistive element and spring contact components from the joystick assembly. By eliminating these contact-based components entirely, the source of abrasion and wear is removed, significantly extending the operational lifespan of the joystick.
3Reliability
If spring contact moves along resistive element, then voltage change can be measured, but contact wear causes resistance deviation and joystick drifting
Solution Approach 1:
The patent substitutes the contact-based voltage measurement system with an inductive measurement system. Instead of measuring voltage division through physical contact with a resistive element, the system measures changes in inductance or magnetic flux coupling as the movable core responds to mid rod position, providing stable and drift-free measurements.
Solution Approach 2:
The movable core serves as an intermediary that translates mechanical position into magnetic field modulation. This indirect coupling mechanism eliminates direct contact between the sensing system and moving components, preventing wear-induced resistance deviations and the resulting joystick drifting phenomenon.
4Ease of operation
If dead zone is created around rest position, then mid rod position can be mapped, but character moves even when user is not moving mid rod
Solution Approach 1:
The patent replaces the dead zone-based position mapping approach with continuous inductive sensing that provides accurate position feedback across the entire range of motion. The inductive system's high resolution and stability eliminate the need for dead zones, allowing precise detection of even minimal mid rod movements without causing unwanted character movement.
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
The inductive joystick achieves lower component tolerance variations and longer lifespan by reducing contact between components, thereby improving accuracy and preventing joystick drifting.
Implementation Method 1
The at least one transmitter coil may be configured to induce at least one signal in the at least one receiver coil
Implementation Method 2
the at least one metal dial may be configured to interfere with the induction of the at least one signal such that relative movement between the at least one surface and the at least one metal dial may vary the at least one induced signal based on a position of the at least one metal dial
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
An inductive joystick may include a control structure including an elongate member movable along at least one direction substantially perpendicular to its length; and a position sensing assembly including a printed circuit board having at least one surface arranged adjacent to the control structure and at least one metal dial arranged over the at least one surface. The at least one surface may be substantially parallel with the elongate member's length and with the at least one direction, and may be provided with at least one transmitter coil and at least one receiver coil. In use, the transmitter coil(s) may induce signal(s) in the receiver coil(s) and the metal dial(s) may interfere with the induction. Moving the elongate member may cause relative movement between the surface(s) and the metal dial(s) which may vary the induced signal(s) based on a position of the metal dial(s).