Earbud Wearing Orientation Detection Using Inertial Sensors

The patent replaces the gravity-based acceleration sensor system with an inertial sensor system that detects movement patterns and rotation center points. This substitution eliminates dependence on gravitational direction, allowing accurate wearing angle detection regardless of user posture (sitting, lying down, etc.). The inertial sensors capture linear acceleration and angular velocity to compute rotation center points, which remain valid in any orientation.

The patent introduces movement detection and rotation center point calculation as intermediary steps between sensor input and wearing angle determination. Instead of directly using gravity vector from acceleration sensors, the system uses inertial sensors to detect characteristic movement patterns during insertion, identifies rotation center points, and derives wearing angles from these intermediaries. This indirect approach provides more reliable angle estimation across various user postures.

The patent implements feedback by detecting the actual wearing orientation through inertial sensor data and rotation center point analysis, then using this information to dynamically adjust stereo sound output. The system continuously monitors wearing state and corrects audio channel assignment accordingly, providing feedback loops that ensure left/right sound channels are properly assigned even when devices are worn in reverse or non-standard orientations.

The patent makes the audio output configuration dynamic rather than fixed. Instead of hardcoding left/right device assignments, the system dynamically determines wearing orientation based on inertial sensor measurements and rotation patterns, then adapts the stereo sound mapping in real-time. This dynamic approach allows the system to handle reverse wearing, rotated wearing, and various user postures without requiring physical left/right distinctions on the devices themselves.