Inside-Out Magnetic Tracking for Virtual/Augmented Reality Applications
PubDate: November 2021
Teams: Purdue University
Writers: Mohit Singh; R. Abhishek Shankar; Byunghoo Jung
High definition 6 degrees of freedom (6-DoF) tracking in the Personal Area Tracking (PAT) region offers a wide range of applications. In this region, inside-out trackers can potentially offer the advantage of being portable. Outside-in trackers, though offering superior performance on average, lack this portability which might limit the number of PAT applications. Thus, there is a need for developing inside-out trackers that can achieve comparable performance. To that end, a tracking system based on AC magnetic field and inertial measurement units (IMUs) has been developed. It consists of a transmitter that can be integrated into a headset and multiple wireless trackers. The tracking system is compact, portable, wireless and low power consuming. The system is optimized to minimize jitter and latency, which are crucial for providing a good user experience in Virtual/Augmented Reality (VR/AR) applications. The compact design is compatible with mobile computing units such as a smartphone. This work presents the challenges associated with the magnetic field symmetry that hinders 8-octant tracking. A method using motion correlation is implemented to perform 8-octant tracking. A position jitter of less than 1 mm up to 1 m, an update rate of 400 Hz, and a latency of about 5 ms have been achieved through sensor fusion, on-the-fly calibration, and filtering.