Optical Tracking Centroid Correction for Cylindrical Markers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical tracking systems face accuracy issues due to misalignment between optical and volumetric centroids of markers, particularly with non-spherical shapes like cylinders, which affects the precision of tracking and requires complex calibration processes.
Innovation Solution
The tracking system employs an iterative compensation process using offset error vectors to correct the optical centroids of markers, allowing for accurate determination of the pose of tracked objects without requiring an initial pose estimate, and can utilize markers with uniform reflective coatings for improved accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If cylindrical markers are used to maintain wide viewing angles, then tracking coverage is improved, but misalignment between optical and volumetric centroids increases causing tracking accuracy to deteriorate
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the offset error vector parameters based on the marker's pose and viewing angle. The system calculates compensation values that change with the marker's orientation and position, allowing cylindrical markers to maintain both wide viewing angles and high tracking accuracy through continuous parameter adaptation.
2Measurement precision
If iterative compensation processes are implemented to correct centroid misalignment, then tracking accuracy is improved, but computational complexity and processing time increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing offset error vector parameters for various marker poses and viewing angles during system initialization. This pre-computation allows the real-time tracking system to simply lookup and apply pre-determined compensation values, significantly reducing computational complexity during actual operation while maintaining high tracking accuracy.
3Ease of manufacture
If uniform reflective coatings are applied to cylindrical markers, then manufacturing simplicity and cost are improved, but optical variability on the surface increases reducing tracking precision
Solution Approach 1:
The patent applies feedback by using the detected optical centroid position and the known volumetric centroid to calculate an offset error vector. This feedback mechanism allows the system to automatically compensate for optical variability caused by uniform reflective coatings on cylindrical markers, maintaining high tracking precision while enabling simple and cost-effective manufacturing processes.
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 tracking accuracy for cylindrical markers by reducing surface variability and maintaining wide viewing angles, enabling lower-cost manufacturing and more precise tracking without the need for initial object pose knowledge.
Implementation Method 1
The marker can be a sphere. In some implementations, the marker can be a cylinder. The tracking system often includes a disk or sphere among the markers for the tracked object because, for these shapes, an optical centroid of the object in the two-dimensional image space (e.g., recorded in the sensor image plane) is in-line with a volumetric centroid of the object in three dimensional (3D) space when the marker is viewed from any angle.
Implementation Method 2
Generally, an optical sensor (e.g., a camera) is positioned near the source of the optical signal and configured to detect the reflected optical signal from the markers.
Data Source
AI summary
Tracking system for tracking one or more reflective markers includes at least two optical sensors configured to obtain image data of an environment that includes at least one marker. The tracking system obtains the image data from the at least two optical sensors. The tracking system is configured for extracting, from the image data, optical signatures representing reflections of the optical signal from at least one marker, determining optical centroids of the optical signatures of the at least one marker, estimating an initial pose for at least one marker, determining offset error vectors from the optical centroids of the at least one marker based on the initial pose, determining corrected optical centroids based on the offset error vectors and the optical centroids, and determining a corrected three dimensional position of the marker in the environment based on the corrected optical centroids of the marker.