Accelerometer Attached Angle Correction via Wavelet Transform
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Solution Overview
Problem
Existing navigation devices struggle to accurately detect the moving state of a movable body due to errors caused by bias and noise components in accelerometer output, leading to incorrect calculation of attached angles and subsequent navigation issues.
Innovation Solution
A moving state detecting device equipped with an accelerometer and an acceleration correcting module that frequency-divides acceleration signals to separate bias, gravity, and noise components, using wavelet transforms to estimate and correct attached angles, thereby improving the accuracy of speed and pitch angle calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If acceleration data from the accelerometer is used directly to calculate attached angle, then the calculation process is simple, but the attached angle cannot be accurately calculated due to bias and noise components
Solution Approach 1:
The patent segments the acceleration signal into different frequency components using wavelet transform, separating the bias component (low frequency), gravity component (medium frequency), and noise component (high frequency). This segmentation allows selective use of only the gravity and movement acceleration components for attached angle calculation, eliminating the influence of bias and noise while maintaining a systematic calculation approach.
Solution Approach 2:
The patent extracts only the necessary frequency components (gravity and movement acceleration) from the full acceleration signal by using wavelet transform to decompose and reconstruct the signal. By taking out and removing the bias and noise components, the calculation uses only the useful signal portions, thereby improving attached angle accuracy without requiring complex filtering methods.
2Measurement precision
If frequency division and wavelet transform are applied to separate bias and noise components, then attached angle accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical or hardware-based filtering systems with a software-based wavelet transform algorithm. This substitution allows for precise frequency component separation and noise removal through computational methods, achieving high attached angle accuracy while avoiding the need for additional physical sensors or complex hardware filtering circuits.
Solution Approach 2:
The patent changes the parameter representation of the acceleration signal from the time domain to the frequency domain through wavelet transform. By transforming the signal parameters and analyzing them in the frequency domain, the system can selectively process different frequency components, improving measurement precision while using standard signal processing techniques rather than complex hardware modifications.
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
The solution enables highly accurate detection of speed and pitch angles by removing unnecessary components from accelerometer data, ensuring precise navigation even on varying terrain.
Implementation Method 1
an accelerometer 20... calculates an acceleration of the movable body
Implementation Method 2
an accelerometer 20... calculates an acceleration of the movable body
Data Source
AI summary
To accurately calculate an attached angle of an accelerometer and accurately correct an acceleration that is obtained from the accelerometer: a frequency analyzing module of an acceleration corrector divides a sensor coordinate system acceleration into a bias frequency component, a gravity frequency component, a movement acceleration frequency component, and a noise frequency component, through a wavelet transform. The frequency analyzing module outputs a sum component of the gravity frequency component and the movement acceleration frequency component to an attached angle estimating module and a correcting operation module. The attached angle estimating module estimation-calculates the attached angle of an accelerometer and outputs it to the correcting operation module. The correcting operation module corrects the acceleration, which is including of the sum component of the gravity frequency component and the movement acceleration frequency component, based on the estimation-calculated attached angle to calculate a movable body coordinate system acceleration.