3D Location Measuring Device Robust Estimation
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Solution Overview
Problem
Conventional location measuring devices face challenges in accurately determining three-dimensional coordinates of a camera or object due to incorrect corresponding points, leading to inaccurate calculations and slow convergence, especially when dealing with errors and inappropriate feature points.
Innovation Solution
The device employs a robust estimation method, such as LMedS, to eliminate large errors before estimation calculation, using threshold processes to identify and remove incorrect corresponding points, and applies affine transformation parameters for coordinate transformation, ensuring quick convergence and high accuracy in measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the least squares method is used for coordinate calculation, then the calculation can be performed, but the convergence is slow and accuracy deteriorates when incorrect corresponding points are present
Solution Approach 1:
The patent applies preliminary action by performing robust estimation before the final coordinate calculation to identify and remove incorrect corresponding points. The flowchart shows that robust estimation is executed in step S234-S235 before bundle adjustment, eliminating erroneous data points that would otherwise slow down and reduce the accuracy of subsequent least squares calculations.
Solution Approach 2:
The patent extracts and removes incorrect corresponding points from the dataset before performing coordinate calculations. The robust estimation process identifies outliers and eliminates them, so that only correct corresponding points remain for the final calculation, thereby improving both accuracy and convergence speed.
2Quantity of substance
If incorrect corresponding points are included in the calculation, then more data points are available for processing, but the measurement accuracy deteriorates and solution convergence fails
Solution Approach 1:
The patent extracts incorrect corresponding points from the dataset through robust estimation and removes them before final calculation. This selective extraction maintains the quantity of valid data points while eliminating erroneous ones, preserving data volume benefits without the accuracy penalty of including incorrect points.
Solution Approach 2:
The patent implements feedback by using robust estimation to evaluate the quality of corresponding points and provide feedback for their selection or rejection. The process iteratively assesses residuals and determines whether points are correct or incorrect, feeding this information back into the calculation process to ensure only accurate points are used.
3Quantity of substance
If a stereo pair with many corresponding points is chosen, then more data is available for calculation, but the solution convergence deteriorates when many points are incorrect
Solution Approach 1:
The patent applies preliminary action by performing robust estimation on the stereo pair before bundle adjustment to identify and remove incorrect corresponding points. This preliminary processing ensures that only correct points remain, preventing convergence deterioration while maintaining the benefits of having multiple data points for accurate measurement.
Data Source
AI summary
To realize high speed and high precision with device and method of three-dimensional measurement by applying estimating process to points corresponding to feature points in a plurality of motion frame images. With the device and method of calculating location information through processes of choosing a stereo pair, relative orientation, and bundle adjustment and using corresponding points of feature points extracted from respective motion frame images, each process is made up of two stages. To the first process section (stages: 5A and 6A), robust estimation is applied to determine estimated values of calculation parameters. In the second process section (stages: 5B and 6B), corresponding points and stereo pair of large residual errors are excluded, and estimating calculation is carried out again to make measurements in three dimensions.