Comparing Algorithms for Accurate Tracking in Virtual Reality with a Low-Cost MIMU

• Júlia Tannús UFU
• Eduardo Naves UFU

Resumo

Due to recent advances in sensing technology, it has become possible to estimate the absolute orientation of a body for Virtual Reality (VR) applications using low-cost magnetic and inertial measurement units (MIMUs). A MIMU is a device that measures acceleration, rotation rate, and the Earth?s magnetic field. Using this data, the orientation can be determined with a sensor fusion algorithm (SFA). This paper compares four approaches to estimate orientation using the InvenSense MPU-9250 MIMU, namely 1 - reading quaternions straight from its Digital Motion ProcessorTM, 2 - using only accelerometer and magnetometer data, 3 - using Mahony open source SFA, and 4 - using Madgwick open source SFA. Basic static, dynamic and magnetic interference tests are performed. The results show that both 1 and 2 did not provide an acceptable estimate for the application, because 1 drifted 43.38° in 10 minutes and 2 presented low stability (sd = 2.46°) and accuracy (peak error = 59.2°). Therefore, either 3 or 4 could be used, with 4 obtaining the best absolute orientation (sd = 0.06°, peak error = 4.46°) but presenting the slowest response and 3 having a less accurate estimation (sd = 0.41°, peak error = 38.72°) than 4, but being faster.

Palavras-chave: magnetic and inertial measurement unit, sensor fusion, motion tracking, inertial sensor