Magnetoresistive Quadrant Detection for Accurate Multi-Turn Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic multi-turn sensors require 360° angle information to resolve ambiguities in domain wall propagation, which is not provided by 180° absolute angle sensors like AMR sensors, leading to incorrect turn count readings due to domain wall propagation timing inconsistencies.
Innovation Solution
Incorporating a magnetoresistive quadrant detector, such as GMR elements, to determine the quadrant of the magnetic field angle, combining with a 180° angle sensor to provide 360° absolute angle information and correct turn count readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 180° absolute angle sensor (AMR sensor) is used, then the angle sensor is more robust and precise, but it cannot provide 360° angle information needed to resolve ambiguities in multi-turn sensor readings
Solution Approach 1:
The angle measurement function is segmented into two parts: the 180° AMR sensor provides robust angle measurement within a half-turn, while the quadrant detector (using GMR elements) provides quadrant identification. Together they reconstruct the full 360° angle information needed to resolve multi-turn ambiguities, allowing each component to operate in its optimal range.
Solution Approach 2:
The quadrant detector acts as an intermediary component that bridges the gap between the 180° AMR sensor and the multi-turn sensor. It provides the additional quadrant information that the AMR sensor alone cannot provide, enabling the system to resolve ambiguities without requiring the AMR sensor to directly provide 360° information.
2Measurement precision
If domain wall propagation timing is not synchronized with magnetic field rotation, then turn count readings become incorrect, but adding complex synchronization mechanisms increases device complexity
Solution Approach 1:
The quadrant detector provides feedback information about the current magnetic field quadrant to the processing circuit. This feedback allows the system to identify when domain wall propagation timing inconsistencies occur and to correct the turn count readings accordingly, maintaining measurement precision without complex hardware synchronization mechanisms.
Solution Approach 2:
The system changes the interpretation parameter of the angle sensor output based on the quadrant information. By adjusting how the 180° angle data is interpreted and combined with quadrant data, the system resolves timing ambiguities in domain wall propagation without requiring physical synchronization hardware.
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 quadrant detector resolves ambiguities in multi-turn sensor readings by identifying the magnetic field quadrant, ensuring accurate turn count measurements without additional space or complexity.
Implementation Method 1
Magnetic sensing devices comprising single turn angle sensors and multi-turn sensors are commonly used... Magnetic multi-turn sensors typically include magnetoresistive elements that are sensitive to an applied external magnetic field. The resistance of the magnetoresistive elements can be changed by rotating a magnetic field within the vicinity of the sensor.
Implementation Method 2
An example is a steering wheel in a vehicle... an anisotropic magnetoresistive (AMR) angle sensor
Implementation Method 3
The quadrant detector is formed of at least two magnetoresistive elements, preferably giant magnetoresistive (GMR) elements, which may be integrated to the multi-turn sensor die or provided on a separate die within the sensor package.
Data Source
AI summary
The present disclosure provides a magnetoresistive quadrant detector for use in a magnetic sensing device comprising a magnetic multi-turn sensor and an angle turn sensor, in particular, an angle sensor configured to provide 180° absolute angle measurements, such as an anisotropic magnetoresistive (AMR) angle sensor. The quadrant detector is formed of at least two magnetoresistive elements, preferably giant magnetoresistive (GMR) elements, which may be integrated to the multi-turn sensor die or provided on a separate die within the sensor package. The magnetoresistive elements are configured to provide a unique combination of resistance states for each quadrant of magnetic field direction. This quadrant information can then be used to remedy any ambiguities in the multi-turn measurement without needing 360° absolute angle information from the single turn angle sensor.