Magnet Position Tracking via Differential Magnetic Field Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the position and orientation of a magnet relative to a magnetometer array suffer from errors due to ambient and offset signal fluctuations, requiring cumbersome initialization processes and limited precision, especially when the magnet is close to the array.
Innovation Solution
A method that involves measuring a reference magnetic field, calculating differential magnetic fields, and iteratively estimating the magnet's position using a recursive estimator, such as a Kalman filter, to account for ambient and offset signals, allowing for more frequent reinitialization and improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional initialization method is used (magnet placed at sufficient distance), then ambient and offset signals can be measured accurately, but the method becomes cumbersome and time-consuming
Solution Approach 1:
The patent extracts and separates the ambient signal and offset signal measurements from the magnet position measurement process. By measuring these signals at multiple time points and subtracting them from the total magnetic field measurements, the method isolates the magnet's contribution to the field, eliminating the need for cumbersome initialization procedures while maintaining measurement precision.
Solution Approach 2:
The patent performs preliminary measurements of ambient and offset signals at multiple time points before final position calculation. These preliminary actions (measuring ambient field at T0, T1, T2 and offset signals at T3, T4, T5) enable the system to compensate for drift and fluctuations without requiring the magnet to be placed at a specific distance during initialization.
2Measurement precision
If magnet is placed close to magnetometer array, then position tracking precision improves, but ambient and offset signal fluctuations cause measurement errors
Solution Approach 1:
The patent implements feedback by continuously measuring ambient and offset signals at multiple time points (T0-T5) and using these measurements to compensate for drift and fluctuations in subsequent position calculations. The system feeds back the calculated ambient and offset signals to correct the total magnetic field measurements, maintaining reliability even when the magnet is close to the array.
Solution Approach 2:
The patent employs periodic measurement of ambient and offset signals at distinct time points interspersed with position measurements. This periodic action (measuring ambient at T0, T1, T2 and offset at T3, T4, T5) allows the system to capture temporal variations and compensate for drift, ensuring reliable measurements regardless of magnet proximity.
3Reliability
If initialization is carried out frequently, then measurement drift is reduced, but the process becomes more time-consuming
Solution Approach 1:
The patent maintains continuity by performing ambient and offset signal measurements at multiple time points throughout the operation sequence rather than requiring separate initialization phases. The useful action of measuring reference signals continues interspersed with position measurements, allowing drift compensation without interrupting the overall process or requiring dedicated reinitialization time.
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
This approach enhances the precision of magnet position determination and allows for more frequent reinitialization, reducing errors and constraints associated with traditional methods, enabling accurate tracking of the magnet's movement.
Implementation Method 1
Each magnetometer being able to measure a magnetic field generated by the magnet along at least one measurement axis
Implementation Method 2
calculating a differential magnetic field representing a difference, for each magnetometer, between the magnetic field measured in step c) and the reference magnetic field measured in step a)
Data Source
AI summary
The invention is a method for tracking a position of a magnet moving relative to a magnetometer array. On the basis of the magnetic field detected by each magnetometer of the array, the position of the magnet is estimated. This estimation is based on taking into account a reference magnetic field established beforehand, this reference magnetic field being subtracted from the magnetic field detected by each magnetometer, so as to form a differential measurement. The various successive estimations of the position of the magnet allow its path to be tracked.