Magnetic Position Sensor Error Detection Through Angle Comparison
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Solution Overview
Problem
Existing magnetic position sensor systems lack error detection capabilities and are often compromised by external disturbance fields, necessitating a trade-off between accuracy, robustness, and cost.
Innovation Solution
A magnetic position sensor system that determines position using a combination of magnetic field components and calculates angles based on ratios of differences and sums, allowing for error detection by comparing these angles, even in the presence of external disturbance fields, without increasing the number of sensor elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If error detection capability is added to magnetic position sensor systems, then reliability is improved, but device complexity increases
Solution Approach 1:
The sensor system is divided into multiple independent sensor elements (first sensor with first and second sensor elements, second sensor with third and fourth sensor elements). Each sensor element independently measures magnetic field components, and the processing unit combines these segmented measurements to calculate angles for error detection. This segmentation enables error detection without requiring a completely new sensor architecture.
Solution Approach 2:
The existing sensor elements serve dual purposes: they measure magnetic field components for position determination, and simultaneously provide data for error detection through angle comparison. The processing unit performs multiple functions - calculating first angle from difference ratios and second angle from sum ratios - using the same sensor inputs, thereby adding error detection capability without proportionally increasing hardware complexity.
2Measurement precision
If additional sensor elements are added to improve measurement accuracy and error detection, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The system calculates two angles (first angle from difference ratios, second angle from sum ratios) and compares them to detect errors. This feedback mechanism uses the measurements from the existing sensor elements to verify their own accuracy, allowing error detection without adding more sensor elements. The comparison of angles provides a self-verification feedback loop.
Solution Approach 2:
The patent changes the mathematical parameters used for processing sensor data - specifically using ratios of differences and ratios of sums to calculate angles. This parameter transformation enables error detection capability from the same sensor elements, improving measurement precision through computational methods rather than adding physical sensor elements.
3Reliability
If the sensor system is made more robust against external disturbance fields, then reliability is improved, but measurement precision may be compromised
Solution Approach 1:
The system converts the vulnerability to external disturbance fields into a beneficial error detection mechanism. By calculating both a first angle from difference ratios and a second angle from sum ratios, and comparing them, the system can detect when external disturbance fields cause inconsistent measurements. This allows the system to maintain robustness by identifying and rejecting erroneous measurements caused by external interference.
Solution Approach 2:
The system creates a computational copy of the measurement data by calculating both angle values from different mathematical combinations of the same sensor inputs. This copying allows for cross-validation - if external disturbance fields affect one measurement path differently than the other, the discrepancy reveals the presence of interference, enabling the system to maintain precision by rejecting compromised measurements.
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 accurate position determination while detecting errors in sensor elements, maintaining robustness against external interference, and does so without requiring additional physical sensor elements.
Implementation Method 1
a first sensor configured for determining a first magnetic field component (e.g. Bx1) and a second magnetic field component (e.g. By1 or Bz1) at a first sensor location
Data Source
AI summary
Method of determining a position of a sensor device relative to a magnetic source, includes: a) determining a first and a second magnetic field component at a first sensor location; b) determining a third and a fourth magnetic field component at a second sensor location; c) determining a first difference of the first and third component, and determining a second difference of the second and fourth component, and determining a first angle based on a ratio of the first and second difference; d) determining a first sum of the first and third component, and determining a second sum of the second and fourth component; e) determining a second angle based on a ratio of said first and second sum; f) comparing the first and second angle to detect error.