Wearable Motion Tracking Calibration Using Simulated Magnetometer Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable audio devices face challenges in accurately estimating spatial orientation due to the absence of magnetometers, leading to inaccuracies in yaw direction measurements and calibration drift caused by hardware aging and temperature changes.
Innovation Solution
A wearable device uses an accelerometer, gyroscope, and a processing device to perform motion tracking calibration by incorporating simulated magnetometer data from an offboard computing device, enabling nine-degree-of-freedom tracking to correct for yaw drift and improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetometer is used in the wearable device, then the measurement precision of spatial orientation is improved, but the device complexity and power consumption increase
Solution Approach 1:
The patent introduces an offboard computing device as an intermediary that generates simulated magnetometer data. This external component provides the missing magnetic field information without requiring a physical magnetometer in the wearable device, thus maintaining measurement precision while avoiding the complexity and power consumption of incorporating actual magnetometer hardware.
Solution Approach 2:
The patent creates a simulated copy of magnetometer data through computational modeling. The offboard computing device generates simulated magnetometer readings based on device orientation and movement patterns, providing a virtual replica of what a physical magnetometer would produce without the associated hardware requirements.
2Reliability
If motion tracking calibration is performed continuously, then the reliability of spatial audio localization is improved, but the use of energy increases
Solution Approach 1:
The patent implements periodic calibration by detecting specific calibration opportunities (such as when the device is stationary or in known positions) and performing calibration only at those moments. This periodic approach maintains localization reliability by regularly updating calibration data while avoiding continuous calibration that would waste energy during normal operation.
Solution Approach 2:
The system performs self-calibration by automatically detecting calibration opportunities and executing calibration procedures without user intervention. The wearable device monitors its own state (acceleration, orientation) and autonomously determines when calibration should be performed, optimizing the balance between reliability and energy consumption.
Data Source
AI summary
A wearable device is provided, including an accelerometer, a gyroscope, and a processing device. The processing device is configured to receive acceleration data from the accelerometer, receive orientation data from the gyroscope, and receive simulated magnetometer data from an offboard computing device. Based at least in part on the acceleration data, the orientation data, and the simulated magnetometer data, the processing device is further configured to perform motion tracking calibration to obtain an estimated position and orientation of the wearable device relative to the offboard computing device. The processing device is further configured to output the estimated position and orientation to an additional computing process.