Rotating Magnetization Permanent Magnet Position Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems lack efficient and economic methods for determining the position of a permanent magnet, which is crucial for detecting the position of movable parts in various applications, such as transmissions and driveshafts.
Innovation Solution
A device and method utilizing a permanent magnet with a compact, rotating magnetization direction and at least one magnetic field sensor, where the magnet is arranged in an inner spatial region and the sensor in an outer spatial region, allowing for continuous detection of the magnetic field changes as the magnet moves, enabling precise position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a permanent magnet is used to detect the position of movable parts, then the position detection capability is improved, but the system complexity and manufacturing cost increase
Solution Approach 1:
The permanent magnet serves dual purposes: it is both the object whose position needs to be detected and the source of the magnetic field for detection. By magnetizing the movable part itself, the system eliminates the need for separate markers or indicators, reducing component count and system complexity while maintaining position detection capability
Solution Approach 2:
The permanent magnet is integrated into the movable part structure, serving multiple functions: structural component, position indicator, and magnetic field source. This multi-functionality reduces the number of separate components needed in the system, simplifying both the device structure and manufacturing process
2Measurement precision
If the sensor is placed inside the magnet's spatial region, then measurement precision is improved, but manufacturing difficulty and mounting tolerance sensitivity increase
Solution Approach 1:
Instead of placing the sensor inside the magnet's spatial region (inner region), the patent inverts the arrangement by placing the sensor in the outer spatial region. This inversion simplifies manufacturing and mounting while still enabling accurate magnetic field detection, as the sensor detects the magnetic field generated by the magnet from the outside
3Measurement precision
If the magnetization direction rotates continuously around the path, then position detection accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs continuous rotation of the magnetization direction around the path as a parameter change strategy. By varying the magnetization orientation continuously along the circular path rather than using discrete poles, the system achieves high position detection accuracy. The evaluation unit processes the magnetic field variations caused by this continuous rotation to determine angular position with high precision
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 allows for accurate and cost-effective detection of the permanent magnet's position, thereby determining the position of associated parts, with robustness against external interference and mounting tolerances.
Implementation Method 1
the permanent magnet is magnetized in such a way that the magnetization direction along the path rotates continuously around the path
Implementation Method 2
at least one magnetic field sensor configured to detect the magnetic field generated by the permanent magnet in the case of a relative movement between the permanent magnet and the magnetic field sensor
Data Source
AI summary
A device comprises a permanent magnet, a magnetic field sensor, and an evaluation circuit. The permanent magnet has a body extending along a path, wherein in a movement travel region the permanent magnet has a continuous north pole and a continuous south pole and is magnetized in such a way that the magnetization direction along the path rotates continuously around the path. The permanent magnet is arranged in an inner spatial region and the at least one sensor is arranged in an outer spatial region, wherein in cross section perpendicular to the path the inner spatial region and the outer spatial region are separated from one another by an outwardly convex line. The magnetic field sensor is configured to detect the magnetic field generated by the permanent magnet. The evaluation circuit is configured to determine the position of the permanent magnet using the detected magnetic field.