Angular Position Sensor Using Hall Array and Fourier Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing angular position sensors are not robust enough to provide accurate position data in hostile environments, such as those encountered in aircraft anti-skid braking systems, and often require complex configurations with multiple magnets and sensors, which are susceptible to heat damage and weight issues.
Innovation Solution
A robust angular position sensor system using a circular target plate with alternating North-South polarity magnets and a stationary sensor board with 72 Hall effect sensing elements, separated by a small air gap, which employs normalization and Fourier algorithms to accurately determine the angular position without direct coupling, allowing for precise wheel speed and acceleration calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a driveshaft is used to distance the sensor from harsh conditions, then reliability is improved, but device complexity and weight increase
Solution Approach 1:
The patent removes the driveshaft component entirely and places the sensor directly on the rotating assembly. The sensor housing is integrated with the rotating assembly, eliminating the need for mechanical coupling through a driveshaft. This extraction of the driveshaft simplifies the system while maintaining sensor reliability through direct mounting in the harsh environment.
Solution Approach 2:
The patent introduces a protective sensor housing that serves as an intermediary between the sensor and the harsh environment. This housing provides thermal and environmental protection while allowing the sensor to be mounted directly on the rotating assembly, eliminating the need for a driveshaft mediator.
2Measurement precision
If Hall sensors are used to generate wheel position data, then measurement capability is improved, but susceptibility to heat damage increases
Solution Approach 1:
The patent introduces a non-magnetic, thermally insulating housing as an intermediary between the Hall sensors and the harsh thermal environment. This housing protects the sensors from excessive heat while allowing them to function accurately in measuring angular position.
Solution Approach 2:
The patent modifies the thermal parameters of the sensor environment by introducing thermal insulation barriers and positioning the sensors away from direct heat sources through strategic placement on the rotating assembly, changing the thermal conditions from hostile to acceptable for Hall sensor operation.
3Measurement precision
If multiple magnets and sensors are used to achieve desired accuracy, then measurement precision is improved, but device complexity and weight increase
Solution Approach 1:
The patent combines multiple sensing functions into a single integrated sensor housing mounted on the rotating assembly. The housing integrates thermal protection, mechanical mounting, and sensor positioning functions, reducing the overall number of components and weight while maintaining measurement precision through careful sensor arrangement.
Solution Approach 2:
The sensor housing serves multiple functions simultaneously: it provides thermal insulation, mechanical support, structural integrity, and precise sensor positioning. This multi-functionality reduces the need for separate components, thereby reducing weight and complexity while maintaining accurate angular position measurement.
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 provides highly accurate angular position data and wheel speed measurements, even in harsh conditions, with improved robustness and reduced complexity, making it suitable for aircraft applications.
Implementation Method 1
a stationary sensor board with 72 Hall effect sensing elements
Data Source
Figure 1~3
AI summary
An angular position sensor (24) and method that relies on a stationary- circular array of Hall sensors (18) and a rotatable circular array of magnets (16) arranged about a common axis (22). A periodic and simultaneous reading of all of the Hall sensor outputs is used to determine angular velocity.