Halbach Magnetic Angle Sensing With Multi-Turn Memory
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Solution Overview
Problem
Existing magnetic angle measuring devices face challenges in achieving precise and reliable operating behavior while being economically manufacturable, particularly in ensuring non-volatile storage of angular position data during power outages.
Innovation Solution
A magnetic angle measuring device comprising a first and second component group with a Halbach array magnet arrangement and a domain wall memory, where the position detector is axially offset, and a housing provides shielding, using magnetoresistive elements and Hall effect sensors for accurate angular position detection, with a domain wall conductor for multi-turn functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic angle measuring device uses conventional magnet arrangements and position detectors, then the device structure is simple, but the measurement precision and reliability are insufficient
Solution Approach 1:
The device is divided into two separate component groups: a first component group containing the position detector on a printed circuit board, and a second component group containing the Halbach array magnet arrangement. These groups can be manufactured independently and then assembled together, allowing for optimized manufacturing of each component while achieving high measurement precision through their coordinated interaction.
Solution Approach 2:
The position detector is arranged axially offset from the magnet arrangement, creating a three-dimensional spatial relationship rather than a planar one. This axial offset configuration, combined with the Halbach array's specific magnetization pattern, enables precise angular position detection while maintaining a compact overall device structure.
2Reliability
If multi-turn angle measuring devices are used to store revolution data, then the angular position can be determined over many revolutions, but the device complexity increases
Solution Approach 1:
The patent combines the fine position detection capability of the position detector with the revolution counting capability of the domain wall memory into a single integrated device. Both components read from the same Halbach array magnet arrangement, merging multiple functions into one cohesive system that provides both absolute angular position and multi-turn information without requiring separate sensor systems.
Solution Approach 2:
The Halbach array magnet arrangement serves multiple functions simultaneously: it provides the magnetic field pattern for the position detector to determine fine angular position, and it also enables the domain wall memory to count revolutions. This multi-functionality reduces overall device complexity compared to using separate systems for each function.
3Measurement precision
If the position detector is arranged close to the magnet arrangement, then the detection sensitivity is high, but the device is more susceptible to interference fields
Solution Approach 1:
A housing is introduced as an intermediary structure that encloses the magnet arrangement and/or position detector. This housing provides shielding against external interference fields while allowing the position detector to maintain its optimal axial offset distance from the magnet arrangement, thus protecting the sensitive magnetic field interaction from external disturbances.
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
Enables precise angular position determination with multi-turn capability, maintaining accuracy during power outages by integrating domain wall memory for revolution counting and providing robust interference shielding.
Implementation Method 1
The magnet arrangement includes several magnets arranged around the axis as a Halbach array
Implementation Method 2
when the magnet arrangement is rotated relative to the printed circuit board, the position detector can detect a relative angular position
Implementation Method 3
The position detector includes at least one magnetoresistive element, based, for example, on an AMR, GMR, or TMR effect
Implementation Method 4
Alternatively or additionally, the position detector could also include at least one Hall effect sensor
Implementation Method 5
The domain wall storage comprises a domain wall conductor extending across a plane
Implementation Method 6
the domain walls of this sensor can be moved by one or two permanent magnets
Data Source
Figure 1
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AI summary
The invention relates to an angle measuring device comprising a first component group (1) and a second component group (2; 2'), wherein the component groups (1, 2; 2') are rotatably arranged relative to each other about an axis (A). The first component group (1) comprises a position detector (1.5) and optionally a domain wall memory (1.1), wherein the position detector (1.5) is mounted on a printed circuit board (1.2). The second component group (2; 2') has a magnet arrangement comprising several magnets (2.1 to 2.8) arranged as a Halbach array around the axis (A) or configured as a Halbach cylinder (2.9'). When the magnet arrangement is rotated relative to the printed circuit board (1.2), an angular position can be detected by the position detector (1.5). (Figure 2)