Linear-Flux Magnet Layout for Accurate Displacement Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnets with non-linear magnetic flux density patterns make it difficult to accurately measure displacement using magnetic flux sensors, as the magnetic flux density varies inversely with the square of the distance, limiting the effective measurement range and accuracy of distance detection.
Innovation Solution
A magnet with a rectangular shape and sinusoidal magnetization pattern along the diagonal direction is used, allowing the magnetic flux density to vary linearly with displacement, enabling more accurate distance measurement by adjusting the magnetization intensity and range, and using a sensor spaced apart and parallel to the poles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional permanent magnet is used, then the magnetic flux density varies inversely with the square of the distance, but this non-linear variation limits measurement accuracy and requires complex error correction
Solution Approach 1:
The invention changes the magnetization pattern parameter from conventional uniform or radial patterns to a specific sinusoidal distribution pattern along the diagonal direction. This parameter change transforms the magnetic flux density variation from inverse-square non-linear to linear variation with displacement, eliminating the need for error correction while maintaining measurement accuracy
Solution Approach 2:
Instead of trying to correct the non-linear inverse-square relationship through complex software or circuitry, the invention inverts the approach by designing a magnetization pattern that naturally produces linear magnetic flux density variation. This eliminates the problem at its source rather than compensating for it
2Length of stationary object
If a conventional magnet with non-linear magnetic flux density is used, then the effective measurement range is limited, but extending the range requires multiple magnets or complex structures
Solution Approach 1:
By changing the magnetization pattern parameter to a sinusoidal distribution along the diagonal, the invention extends the linear measurement range to 8mm (from -2mm to +6mm) using a single magnet. This eliminates the need for multiple magnets or complex mechanical structures while achieving a longer effective measurement range
3Measurement precision
If the magnetic flux density varies non-linearly with distance, then simple distance measurement is inaccurate, but linear variation requires changing the magnet's shape and magnetization pattern
Solution Approach 1:
The invention changes two key parameters: the magnetization pattern (to sinusoidal distribution along diagonal) and the sensor positioning (spaced 1mm from pole surface and moved parallel to it). These parameter changes achieve linear magnetic flux density variation, and the rectangular shape with diagonal magnetization is manufacturable using conventional techniques
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
This configuration eliminates the need for complex error correction processes, providing a more accurate and reliable location sensor with a longer measurement range by ensuring the magnetic flux density varies linearly, thus enhancing the accuracy of absolute distance measurement.
Implementation Method 1
The space affected by the magnetic force is called a magnetic field. In other words, it can be said that the magnet generates the magnetic field.
Implementation Method 2
A magnet is an object that has a magnetic force and attracts iron powder.
Implementation Method 3
When a magnetic flux passing though coil varies with time, a voltage that is proportional to the variation rate thereof is induced between both ends of the coil (Faraday' electromagnetic induction law).
Implementation Method 4
The hall sensor operates in such a way that, when a magnetic field is applied in a direction perpendicular to a semiconductor device (hall device) while current flows through the electrodes of the semiconductor device (hall device), an electric potential is generated to be perpendicular to the directions of the current and the magnetic field.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a magnet having a linear magnetic flux density, which causes the magnetic flux density thereof to vary linearly and, more particularly, to a magnet having a linear magnetic flux density, in which the shape and magnetization pattern of the magnet are changed so that displacement in proportion to linearly varying displacement from the magnet is more accurately measured using a magnetic flux sensor, thus causing the magnetic flux density to vary linearly (or rectilinearly) according to the displacement. The present invention is configured to have a rectangular shape or a trapezoid shape so that displacement in proportion to linearly varying displacement from the magnet is more accurately measured using a magnetic flux sensor, and is configured such that the value of magnetic flux density varies linearly (rectilinearly) according to the magnetization pattern of the rectangular shape or a trapezoid shape.