Intertwined Magnetic Sensors for Phase Shift Detection
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Solution Overview
Problem
Magnetic sensing systems face challenges in accurately determining the speed and direction of a rotating shaft due to difficulties in achieving the required phase shift between output signals from separate magnetic sensors, which is dependent on precise manufacturing and adjustment, and is costly to fabricate integrated circuits for different pole spacings.
Innovation Solution
A movement sensing system comprising a multi-pole magnet, semiconductor substrate, and intertwined magnetic sensors formed on the substrate with a predetermined angle, producing output signals that are converted to a linear signal, allowing for accurate phase shift without tight manufacturing tolerances or adjustments, and enabling detection of speed and direction with increased resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate magnetic sensors are spaced at a predetermined distance to create phase shift, then speed and direction detection capability is improved, but manufacturing precision and adjustment complexity increase
Solution Approach 1:
The patent combines multiple magnetic sensors onto a single integrated circuit substrate, fixing their relative positions during manufacturing. This eliminates the need for precise field spacing and adjustment, as the sensors are permanently positioned at optimal distances and angles (e.g., 90 degrees) for phase shift generation.
Solution Approach 2:
The integrated circuit is designed to be universal, working with different multi-pole magnet configurations (varying pole counts and spacings). The circuit incorporates multiple sensors that can detect phase shifts across various magnet geometries, making the system adaptable without requiring custom fabrication for each application.
2Measurement precision
If integrated circuit is fabricated for each different ring magnet spacing, then measurement accuracy is improved, but manufacturing cost increases
Solution Approach 1:
A single integrated circuit design incorporates multiple magnetic sensors arranged to work with various multi-pole magnet configurations. The circuit can detect phase shifts for different pole counts and spacings, eliminating the need to fabricate separate circuits for each magnet type and significantly reducing manufacturing costs.
Solution Approach 2:
The system accommodates different magnet parameters (pole count, spacing, diameter) by using multiple sensors with fixed geometric relationships. The phase shift detection algorithm can process signals from sensors responding to various magnet configurations, allowing one circuit design to handle multiple parameter variations.
3Device complexity
If magnetic sensors are placed on the same integrated circuit, then device complexity is reduced, but adaptability to different pole spacings decreases
Solution Approach 1:
The integrated circuit incorporates multiple magnetic sensors positioned at specific geometric relationships (e.g., 90-degree separation) that enable detection of phase shifts across various multi-pole magnet configurations. This universal design maintains low device complexity while achieving broad adaptability to different magnet types and spacings.
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 system achieves accurate and cost-effective detection of speed and direction by ensuring a consistent 90° phase shift between sensor outputs, independent of magnet pole size, doubling the resolution and eliminating the need for precise manufacturing or adjustments, and allowing compatibility with different multi-pole ring magnets.
Implementation Method 1
The first magnetic sensor produces a first output signal in response to movement of the multi-pole magnet. The second magnetic sensor produces a second output signal in response to movement of the multi-pole magnet.
Implementation Method 2
The second magnetic sensor comprises fifth, sixth, seventh, and eighth magnetoresistors connected into a second bridge configuration so as to produce a second bridge output signal in response to movement of the multi-pole magnet.
Data Source
AI summary
A first magnetic sensor is formed on a semiconductor substrate, and the first magnetic sensor produces a first output signal in response to movement of a multi-pole magnet. A second magnetic sensor is formed on the semiconductor substrate so as to be intertwined with the first magnetic sensor and so as to be at a predetermined angle with respect to the first magnetic sensor. The second magnetic sensor produces a second output signal in response to movement of the multi-pole magnet. The predetermined angle is between 0° and 180° exclusive, and the predetermined angle is sufficient to produce a difference in phase between the first and second output signals. An output signal converter converts the first and second output signals to a linear signal.