Relative Angle Estimation via Accelerometer-Gyroscope Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the relative angle between a person's heading and a mobile device's heading lack accuracy, particularly for certain applications.
Innovation Solution
Combining estimates from a multi-axis accelerometer and a multi-axis gyroscope using Kalman filtering to improve signal-to-noise ratio and accuracy, with the accelerometer model determining step-related velocities and the gyroscope model estimating axis rotation, and projecting onto a ground plane to calculate the relative angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If accelerometer readings are used to estimate relative angle, then the system can operate with simple sensors, but the measurement precision is insufficient due to noise in accelerometer data
Solution Approach 1:
The patent combines accelerometer data and gyroscope data through integration and Kalman filtering to estimate relative angle. The accelerometer provides step-related velocity information while the gyroscope provides rotation axis information, and merging these complementary data sources improves measurement precision while compensating for the noise in individual sensors
Solution Approach 2:
The patent introduces an intermediary processing stage that integrates accelerometer readings over step cycles and uses gyroscope data as a reference. This intermediary processing filters noise by integrating over multiple samples and using gyroscope measurements to correct drift, thereby improving the final relative angle estimation accuracy
2Measurement precision
If gyroscope data is used to reduce measurement noise, then the measurement precision improves, but the device complexity increases due to requiring multiple sensor types and complex signal processing
Solution Approach 1:
The patent segments the relative angle estimation into two distinct components: one derived from accelerometer data (step-related velocities) and another from gyroscope data (axis rotation). This segmentation allows each sensor to be processed independently through specialized algorithms before being combined, making the complex processing more manageable and systematic
Solution Approach 2:
The patent implements feedback through Kalman filtering, where the gyroscope measurements serve as feedback to correct the accelerometer-based estimates. The filter continuously adjusts the relative angle estimation by comparing predicted values from accelerometer integration with actual gyroscope measurements, reducing noise while maintaining computational efficiency
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
This approach provides a high-accuracy estimation of the relative angle by integrating noisy accelerometer data and using gyroscope data to reduce measurement noise, enhancing the precision of heading alignment between a person and their mobile device.
Implementation Method 1
estimating horizontal acceleration of the mobile device in first and second orthogonal directions when the person is walking or running based on samples from the multi-axis accelerometer
Implementation Method 2
estimating an axis that the mobile device is rotating about with respect to pendulous motion
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
The present invention relates to a method for estimating a relative angle (θ) between heading (X10) of a person (10) and heading (X12) of a mobile device (12) carried by the person, which method comprises: determining a first estimate of the relative angle using a multi-axis accelerometer (18) of the mobile device; determining a second estimate of the relative angle using a multi-axis gyroscope (20) of the mobile device; and combining the first estimate and the second estimate to a combined estimate of the relative angle (θ) between the person's heading and the mobile device's heading. The present invention also relates to a system for estimating a relative angle (θ) between heading (X10) of a person (10) and heading (X12) of a mobile device (12) carried by the person.