Magnetic Angular Position Sensor Pole Element Flux Concentration
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Solution Overview
Problem
Magnetic angular position sensors with varying air gaps produce non-linear output signals, requiring expensive irregularly shaped magnets to linearize responses, increasing manufacturing costs.
Innovation Solution
A magnetic sensor with a cuboid-shaped movable magnet and a pole element acting as a magnetic field concentrator, mounted on a printed circuit board, focuses the magnetic field to improve linearity and reduce manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If irregularly shaped magnets are used to linearize the sensor output, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
A ferromagnetic pole element is introduced as an intermediary component between the magnet and the magnetic sensor. This pole element shapes and concentrates the magnetic flux to achieve linear sensor output without requiring complex irregular magnet geometries. The pole element acts as a flux guide that transforms the magnetic field distribution to produce a linear relationship between shaft angle and sensor output signal.
Solution Approach 2:
The invention changes the magnetic circuit parameters by introducing a ferromagnetic pole element with specific geometric dimensions and magnetic permeability characteristics. By adjusting the pole element's shape, size, and material properties, the magnetic flux density distribution at the sensor is optimized to achieve linear output across the full angular range, replacing the need for complex magnet shaping.
2Device complexity
If varying air gap is used to detect angular position, then device complexity is reduced, but measurement precision deteriorates due to non-linear output
Solution Approach 1:
The ferromagnetic pole element serves as a flux concentrating intermediary that maintains the simple varying air gap structure while correcting the non-linear output. The pole element's geometry is designed to concentrate and guide magnetic flux such that despite the air gap variation, the sensor receives a linearly varying magnetic field signal corresponding to the shaft angle.
3Ease of manufacture
If cuboid-shaped magnet with pole element is used, then ease of manufacture is improved, but device complexity increases
Solution Approach 1:
The magnetic system is segmented into separate functional components: a simple cuboid magnet, a ferromagnetic pole element, and the magnetic sensor. This segmentation allows each component to be manufactured independently using simple processes, then assembled together. The cuboid magnet can be magnetized uniformly, while the pole element is shaped to provide the necessary flux concentration, achieving both manufacturing simplicity and functional performance.
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 solution achieves linearity error less than 2% and reduces manufacturing costs by using a cuboid-shaped magnet and a ferromagnetic pole element to concentrate and focus the magnetic field, enhancing the sensor's performance and cost-effectiveness.
Implementation Method 1
Magnetic field effect sensors use a magnetic induction element to detect magnetic field variation, which is then converted into electrical signal output corresponding to the angular position of a component
Implementation Method 2
a pole element (106) arranged next to the magnetic sensor (102). The pole element (106) acts as a magnetic field concentrator for the magnetic sensor (102)
Data Source
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AI summary
Sensor arrangements are disclosed. A magnetic sensor is mounted to a printed circuit board. A pole element is arranged next to the magnetic sensor. The pole element acts as a magnetic field concentrator for the magnetic sensor. A movable magnet may be positioned in proximity to the magnetic sensor and the pole element. The movable magnet may be held in a magnet holding element. The magnet holding element may be attached to a rotatable element, such as a shaft.