HeadTrack: Tracking head orientation using wireless signals

Head orientation tracking is critical for a range of mobile computing applications, including AR/VR, assistive technologies, and spatial interaction. Traditional solutions rely on infrastructure-based systems involving cameras, lasers, or high-end inertial sensors—limiting user mobility and constraining deployment to fixed environments.

HeadTrack presents a wearable, infrastructure-free system that estimates a user’s head orientation using wireless signals. The system consists of a necklace-like wearable with a headset and chest-piece, each embedded with ultra-wideband (UWB) radios. By precisely estimating multiple distances between the headset and torso, HeadTrack infers the 3D orientation of the head relative to the body.

To overcome the typical ~10 cm ranging limitation of UWB, the system introduces a reference-assisted design by splitting the transmitted signal across both wireless and wired paths. This approach reduces the ranging error to approximately 5 mm. Additionally, an onboard IMU is used to resolve phase ambiguities and ensure consistent tracking over time.

Evaluated using ViCon ground truth data, HeadTrack achieves a head orientation tracking accuracy of 6.5°, offering a portable, occlusion-free, and cost-effective alternative to conventional motion capture systems. The system demonstrates how body-worn UWB sensing can enable fine-grained, infrastructure-free motion tracking in real-world settings.