Electromagnetic Air Mouse Tracking with IMU Backup for Occlusions
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Solution Overview
Problem
Existing electromagnetic (EM) position tracking systems face challenges in accurately tracking input devices like air mice due to occlusions, leading to loss of range errors and input device representation on computing devices.
Innovation Solution
The implementation of a non-line-of-sight (NLOS) 6-DoF electromagnetic tracking technology in air mouse devices, combined with inertial measurement units (IMU) for backup tracking, ensures continuous pose detection by switching between EM and IMU-based tracking based on proximity and signal noise thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic tracking systems are used for position detection, then tracking accuracy is improved, but occlusions cause loss of range errors and tracking reliability deteriorates
Solution Approach 1:
The patent combines electromagnetic tracking and inertial tracking systems into a unified hybrid tracking system. The EM sensing system provides high-accuracy 6-DoF tracking when available, while the IMU provides backup 3-DoF tracking capability. The system merges these two independent tracking modalities to ensure continuous reliable operation even when EM tracking is occluded or unavailable.
Solution Approach 2:
The system dynamically changes operational parameters by switching between EM-based 6-DoF tracking and IMU-based 3-DoF tracking based on signal quality and proximity conditions. When the EM signal becomes weak or occluded, the system transitions to using inertial measurement data, effectively changing the active sensing modality to maintain tracking reliability.
2Measurement precision
If electromagnetic sensing system is used for pose detection, then measurement precision is improved, but device complexity increases due to multiple sensing systems
Solution Approach 1:
The air mouse device incorporates multiple sensing systems (EM receiver and IMU) that serve dual purposes: the EM system provides primary high-precision tracking, while the IMU serves as both a backup tracking system and provides additional orientation data. This multi-functionality justifies the increased device complexity by providing redundant capabilities and improved overall system performance.
3Reliability
If inertial measurement unit is used as backup tracking, then tracking reliability is improved during occlusions, but measurement precision deteriorates compared to EM tracking
Solution Approach 1:
The system prepares for potential EM signal loss by having the IMU ready as a pre-configured backup tracking system. The inertial sensors continuously collect data and can immediately take over when EM tracking becomes unreliable, providing a cushion against tracking failures. This prior preparation ensures seamless transition and maintains reliability during occlusions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures stable and accurate tracking of input devices in three-dimensional space, maintaining one-to-one motion correlation and improved input device movement stability, even under occlusions, by utilizing NLOS 6-DoF EM tracking and IMU backup.
Implementation Method 1
an electromagnetic sensing system for detecting, for the handheld electronic device, a pose of the handheld electronic device in three-dimensional space
Implementation Method 2
an inertial measurement unit sensor for detecting, for the handheld electronic device, an orientation in three-dimensional space of the handheld electronic device
Data Source
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AI summary
A handheld electronic device is described for controlling three-dimensional content displayed in a user interface of a computing device. The handheld electronic device may include an electromagnetic sensing system for detecting a pose of the handheld electronic device in three-dimensional space and at least one communication module to trigger transmission of the commands to manipulate three-dimensional content displayed in the computing device based on detected changes in the pose of the handheld electronic device.