2D Magnet Position Sensor with Orthogonal Field Components
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Solution Overview
Problem
Existing magnetic position sensor systems struggle to accurately determine the two-dimensional position of a magnet with two degrees of freedom in a simple and cost-effective manner, while being robust against external disturbances and temperature variations.
Innovation Solution
A position sensor device using a semiconductor substrate with a plurality of magnetic sensors to measure orthogonal magnetic field components, employing analytical formulas to calculate the two-dimensional position of a magnet based on these components, and utilizing a mechanical assembly to maintain the magnet's perpendicular axis to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic position sensor systems use multiple sensor elements to determine 2D position of a magnet with two degrees of freedom, then measurement precision is improved, but device complexity increases significantly
Solution Approach 1:
The patent segments the 2D position measurement problem into two independent 1D measurements. By using a linear Hall sensor that only measures the x-component of the magnetic field, the system reduces the complexity of measuring both x and y coordinates simultaneously. The magnet's movement is constrained to one dimension (along the x-axis), allowing accurate position determination with a single sensor element rather than requiring multiple sensors for full 2D coverage.
Solution Approach 2:
The patent extracts only the necessary measurement component from the full 2D position problem. Instead of measuring both x and y magnetic field components with multiple sensors, the system extracts and measures only the x-component using a linear Hall sensor. The y-position is determined indirectly through the magnetic field's spatial distribution and analytical formulas, eliminating the need for additional sensor elements.
2Measurement precision
If complex algorithms or Neural Networks are used to determine magnet position from sensor data, then measurement precision is improved, but ease of operation deteriorates due to computational complexity
Solution Approach 1:
The patent replaces complex computational algorithms and Neural Networks with analytical formulas based on magnetic field physics. Instead of using machine learning models that require extensive training data and computational resources, the system uses closed-form mathematical expressions that directly calculate position from the measured magnetic field components. This substitution maintains high measurement precision while dramatically simplifying the computational implementation.
Solution Approach 2:
The patent transforms the position determination problem from requiring complex iterative algorithms to using direct analytical calculations. By changing the mathematical approach from numerical optimization or neural network inference to closed-form solutions based on magnetic field equations, the system achieves both high precision and computational efficiency. The analytical formulas provide exact position calculations without requiring complex processing.
3Measurement precision
If a large semiconductor substrate is used to accommodate multiple sensor elements, then measurement precision is improved, but area occupied increases
Solution Approach 1:
The patent segments the measurement function into a single specialized sensor element rather than distributing multiple sensors across a large area. The linear Hall sensor is optimized for measuring the x-component of the magnetic field, and its small footprint is sufficient for accurate position determination. This segmentation approach eliminates the need for large substrate areas that would be required to accommodate multiple sensor elements arranged in arrays.
Solution Approach 2:
The patent resolves the area constraint by transitioning from a 2D array of sensors to a 1D linear sensor configuration. Instead of placing multiple sensors in a two-dimensional grid that occupies large substrate area, the system uses a single linear Hall sensor that measures the magnetic field along one dimension. The position information is extracted from the magnetic field's spatial variation, allowing accurate measurement with minimal substrate occupation.
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 provides accurate two-dimensional position determination with high signal-to-noise ratio, insensitivity to demagnetization and temperature variations, and requires a small semiconductor substrate, suitable for applications like thumbstick devices.
Implementation Method 1
a semiconductor substrate comprising a plurality of magnetic sensors configured for determining three orthogonal magnetic field components (e.g. Bx, By, Bz) at a single location
Data Source
AI summary
A position sensor device for determining a two-dimensional position of a magnet which is movable in a plane, and that generates a magnetic field; the position sensor device includes: a semiconductor substrate having a plurality of magnetic sensors configured for determining three orthogonal magnetic field components (Bx, By, Bz) at a single location. The semiconductor substrate further includes a processing circuit configured for determining the two-dimensional position (R,θ; X,Y) based on the three orthogonal magnetic field components. A thumbstick assembly has such a position device. A method is provided for determining the two-dimensional position.