Latency and Distortion compensation in Augmented Environments using Electromagnetic trackers

Augmented reality (AR) systems are often used to superimpose virtual objects or information on a scene to improve situational awareness. Delays in the display system or inaccurate registration of objects destroy the sense of immersion a user experiences when using AR systems. AC electromagnetic trackers are ideally for these applications when combined with head orientation prediction to compensate for display system delays. Unfortunately, these trackers do not perform well in environments that contain conductive or ferrous materials due to magnetic field distortion without expensive calibration techniques. In our work we focus on both the prediction and distortion compensation aspects of this application, developing a “small footprint” predictive filter for display lag compensation and a simplified calibration system for AC magnetic trackers. In the first phase of our study we presented a novel method of tracking angular head velocity from quaternion orientation using an Extended Kalman Filter in both single model (DQEKF) and multiple model (MMDQ) implementations. In the second phase of our work we have developed a new method of mapping the magnetic field generated by the tracker without high precision measurement equipment. This method uses simple fixtures with multiple sensors in a rigid geometry to collect magnetic field data in the tracking volume. We have developed a new algorithm to process the collected data and generate a map of the magnetic field distortion that can be used to compensation distorted measurement data.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Engineering

Year dc:date.available

2010

Author dc:creator

• Himberg, Henry

Contributors dc:contributor

• Yuichi Motai

• Augmented reality
• head tracking
• kalman filter
• orientation prediction
• field mapping
• electromagnetic tracker
• distortion compensation
• Engineering

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/169

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1168