Magnetic Position Determination Using Orthogonal Sensor Differential Fields
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Solution Overview
Problem
Existing object position tracking systems face challenges in accurately determining the position of small movable objects, especially in the presence of stray magnetic fields, as the small magnetic fields produced by these objects can be difficult to discern and may be masked by environmental fields.
Innovation Solution
A system utilizing two sensors positioned orthogonally to measure components of a magnetic field produced by a dipole magnet moving along a predetermined path, with processing circuitry calculating a field angle from differential fields to determine the magnet's position, allowing for precise and reproducible tracking even in the presence of stray fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single magnetic sensor is used to track object position, then the device complexity is reduced, but the measurement precision deteriorates due to inability to accurately distinguish small magnetic fields from stray fields
Solution Approach 1:
The system divides the measurement task by using multiple sensors (first sensor and second sensor) positioned at different locations. Each sensor measures magnetic field components at its specific position, and the processing circuitry combines these segmented measurements to determine the magnet's position, thereby improving measurement precision while maintaining reasonable device complexity
Solution Approach 2:
The patent transitions from single-point measurement to multi-point spatial measurement by positioning sensors at different locations (first sensor position and second sensor position). This dimensional expansion in measurement space enables the system to distinguish small magnetic fields from stray fields through spatial differentiation, improving position determination accuracy
2Weight of moving object
If small magnets are used on movable objects, then the object weight is reduced, but the measurement precision deteriorates because small magnetic fields are difficult to discern from environmental interference
Solution Approach 1:
The processing circuitry extracts the magnet's position information by calculating differential fields between measurements from different sensor positions. This extraction process isolates the small magnetic field signal from the magnet from larger environmental stray fields, enabling accurate position determination even with small magnets
Solution Approach 2:
The system introduces differential field calculation as an intermediary processing step. By computing the difference between magnetic field measurements at different sensor positions, the system creates a differential signal that amplifies the magnet's contribution while canceling out common-mode stray fields, thereby improving detection accuracy for small magnets
3Adaptability or versatility
If magnetic field measurements are taken in the presence of stray fields, then the system operates in realistic environmental conditions, but the measurement precision deteriorates due to field masking
Solution Approach 1:
The system converts the harmful effect of stray fields into a beneficial measurement approach by using differential measurements. By taking measurements at multiple sensor positions and calculating differences, the system causes stray fields to manifest as common-mode signals that cancel out, while the magnet's position-dependent field variations are preserved and enhanced in the differential result
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 and reproducible determination of a magnet's position along a two-dimensional path, effectively overcoming the challenges posed by small magnetic fields and environmental interference, thus facilitating the tracking of small movable objects.
Implementation Method 1
a dipole magnet configured to move along a predetermined travel path within a two-dimensional plane... a first sensor located at a first sensor position and arranged to measure at least two components of a magnetic field produced by the magnet
Data Source
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AI summary
Systems and methods are provided for determining a position of a magnet. The systems and methods utilize a first sensor located at a first sensor position and arranged to measure at least two components of a magnetic field produced by the magnet, a second sensor located at a second sensor position and arranged to measure at least two components of the magnetic field produced by the magnet, and processing circuitry operatively connected to the first and second sensors to receive signals derived from signals outputted by the first and second sensors. A field angle is calculated from a first differential field of a first field dimension and a second differential field of a second field dimension orthogonal to the first field dimension. The first and second differential fields are calculated based on signals outputted by the first and second sensors.