Magnetometer Calibration Power Reduction via Motion Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital compasses in mobile communication devices face challenges in reducing power consumption and error, particularly due to magnetic anomalies and the need for frequent calibration, which can be triggered by stationary states and ferromagnetic objects, leading to inaccurate readings and increased power usage.
Innovation Solution
Implementing a method to suspend magnetometer calibration when the device is in a stationary state and adjusting the calibration rate based on detected conditions, such as motion and orientation changes, to minimize power consumption and reduce errors by postponing calibration during periods of minimal informative data generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetometer calibration is performed frequently to improve measurement accuracy, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The calibration rate is made dynamic rather than static. The system adjusts the calibration frequency based on detected motion conditions - performing calibration at high rate when motion is detected and at low or suspended rate when stationary, optimizing the balance between measurement accuracy and power consumption
Solution Approach 2:
The system changes the calibration parameter (calibration rate) based on detected conditions. By monitoring motion state and orientation changes, the system adjusts when to perform calibration, performing it during motion when informative data is generated and suspending it during stationary states to conserve power
2Measurement precision
If magnetometer calibration is performed during stationary state to improve measurement accuracy, then measurement precision is improved, but calibration errors increase due to magnetic anomalies
Solution Approach 1:
The system takes preliminary action to prevent calibration errors by detecting motion state before performing calibration. By checking whether the device is in motion before initiating calibration, the system prevents calibration during stationary states where magnetic anomalies from ferromagnetic objects would cause errors
Solution Approach 2:
The system uses feedback from motion detection sensors to control the calibration process. By continuously monitoring motion state and orientation changes, the system receives feedback that determines whether calibration conditions are met, creating a closed-loop control system that adapts to current device state
3Reliability
If continuous calibration monitoring is performed to reduce calibration errors, then reliability is improved, but power consumption increases
Solution Approach 1:
Instead of continuous monitoring, the system uses periodic action by only performing calibration monitoring during motion intervals. The system detects motion, performs calibration during the motion interval when informative data is generated, and suspends monitoring during stationary periods, reducing power consumption while maintaining reliability
Data Source
AI summary
Example methods, apparatuses, or articles of manufacture are disclosed herein that may be utilized, in whole or in part, to facilitate or support one or more operations or techniques for reducing power consumption or error of a digital compass.