Hybrid Tracker Snapshot Truthing Drift Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inertial tracker systems experience output drift over time, leading to inaccuracies in tracking data, particularly in applications requiring high accuracy and low latency, such as head-worn displays.
Innovation Solution
A hybrid tracking system that combines a high-speed, low-latency inertial tracker with a high-accuracy, low-latency 'truthing' tracker, using a snapshot data capture technique to synchronize and compare data within a short window, allowing for detection and correction of drift through a snapshot truthing system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a compact inertial tracker is used, then the tracker system becomes smaller and faster, but accuracy deteriorates due to output drift over time
Solution Approach 1:
The patent combines a compact inertial tracker with a larger, more accurate reference tracker into a hybrid system. The inertial tracker provides high-speed updates while the reference tracker corrects drift, merging the advantages of both systems to achieve both speed and accuracy.
Solution Approach 2:
The system uses the reference tracker to continuously monitor and measure drift in the inertial tracker output. This feedback mechanism allows the system to detect and correct accuracy degradation while maintaining the fast update rate of the inertial tracker.
2Measurement precision
If a hybrid tracking system is implemented with drift correction, then accuracy is improved, but device complexity increases
Solution Approach 1:
The patent introduces a snapshot module as an intermediary that periodically captures synchronized data from both trackers. This mediator simplifies the integration process by providing a straightforward method to compare and correct drift without requiring complex continuous synchronization mechanisms.
Solution Approach 2:
Instead of continuous complex synchronization, the system uses periodic snapshot comparisons at defined intervals. This approach reduces computational overhead and system complexity while still effectively correcting drift through regular accuracy checks and corrections.
3Loss of time
If snapshot data capture is used to synchronize trackers, then drift detection speed is improved, but data synchronization precision may be affected
Solution Approach 1:
The system performs preliminary synchronization by capturing snapshots from both trackers at predefined intervals before drift becomes significant. This proactive approach allows for early detection and correction of drift, maintaining synchronization accuracy while minimizing time loss.
Solution Approach 2:
The snapshot interval is dynamically adjusted based on detected drift rates. When drift is minimal, snapshots are taken less frequently, reducing processing overhead. When drift increases, the system increases snapshot frequency to maintain synchronization precision, creating a dynamic balance between speed and accuracy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for detecting and correcting drift associated with operation of a hybrid tracking system is provided. The method obtains a data signal from a first tracker subsystem having a first tracker latency time; for a defined window of time, the method captures snapshot input data for a second tracker subsystem having a second tracker latency time which is longer than the first tracker latency time; and captures synchronized data from the data signal which corresponds to the defined window of time; wherein the defined window of time comprises a time duration shorter than the second tracker latency time, to capture the snapshot input data. The method further calculates second tracker snapshot results from the captured snapshot input data for the second tracker subsystem; calculates first tracker snapshot results from the captured synchronized data from the first tracker subsystem; calculates an error between the first tracker snapshot results and the second tracker snapshot results, to determine a level of drift associated with operation of the first tracker subsystem; and adjusts operation of the first tracker subsystem according to the determined level of drift.