Magnetic Sensor Arrangement for Full 360 Angular Position Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing angular position sensors using magnetic fields are limited to measuring angles within an integer fraction of 360°, such as 180° for quadrupole magnets, due to their rotation-symmetric magnetic field periodicity, making them insensitive to external fields but unable to cover a full 360° range.
Innovation Solution
Introducing a secondary magnetic field with different angular periodicity, generated by additional magnetic poles or sectors of varying magnetization, allows the sensor to calculate a unique angular position over the full 360° range by combining signals from primary and secondary magnetic field components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotation-symmetric magnetic field with integer fraction periodicity of 360° is used, then the sensor is insensitive to external magnetic fields, but the measurement range is limited to an integer fraction of 360°
Solution Approach 1:
The magnetic field is segmented into multiple components with different angular periodicities. The first magnetic field component has an angular periodicity that is an integer fraction of 360° (e.g., 180° for quadrupole), while the second component has a different angular periodicity (e.g., 360° for dipole). This segmentation allows each component to contribute differently to the measurement, enabling full 360° range while maintaining external field insensitivity through the first component.
Solution Approach 2:
The invention introduces asymmetry by combining magnetic field components with different periodicity characteristics. The first component maintains rotation symmetry with integer fraction periodicity for external field rejection, while the second component breaks this symmetry pattern with a different periodicity, enabling the system to distinguish between different quadrants and achieve full 360° measurement capability.
2Measurement precision
If multiple magnetic field components with different angular periodicities are combined, then the measurement range extends to full 360°, but the device complexity increases
Solution Approach 1:
Multiple magnetic field components with different angular periodicities are merged into a single composite magnetic field. The first component (e.g., quadrupole with 180° periodicity) and the second component (e.g., dipole with 360° periodicity) are combined in space, allowing the sensor to detect both components simultaneously through a single sensor assembly, thereby achieving full 360° measurement without proportionally increasing device complexity.
Solution Approach 2:
The magnet assembly is designed to serve multiple functions: the first magnetic field component provides external field insensitivity while the second component extends the measurement range. Both components are generated by the same magnet assembly structure, making it a multi-functional device that achieves both external field rejection and full 360° measurement capability through a single integrated system.
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 approach enables accurate measurement of angular positions from 0° to 360° while maintaining robustness against external magnetic fields, enhancing the sensor's measurement range without compromising sensitivity or precision.
Implementation Method 1
The magnet assembly is arranged such that it forms a magnetic field having at least two magnetic field components with different angular periodicities at the location of the magnetic sensor
Implementation Method 2
the magnetic sensor includes means for sensing the different magnetic field components to produce at least a first and a second sensor element signal
Data Source
AI summary
A magnetic sensor arrangement, comprising: a magnet assembly and a magnetic sensor; the magnet assembly forming a magnetic field having at least two magnetic field components with different angular periodicities at the location of the magnetic sensor and the magnetic sensor including means for sensing the different magnetic field components to produce at least a first and a second sensor element signal; and a computing element for receiving the at least first and second sensor element signals and combining them to produce a unique angular position of the magnet relative to the sensor. A method of determining a unique angular position is also provided.