3D Measurement Edge Weighting for Position Precision

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Solution Overview

Problem

Existing techniques for measuring the position and orientation of objects in mixed reality and robotic tasks face challenges due to unstable edge detection, high processing loads, and insufficient or biased edge observability, leading to precision drops when view-points change.

Innovation Solution

A three-dimensional measurement apparatus that generates view-point images, detects edges, calculates reliabilities, and weights edges based on these reliabilities to improve the precision of position and orientation calculations, using a reliability-assigned model to associate edges from captured images with a three-dimensional geometric model.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If edges are detected from an entire two-dimensional image to ensure comprehensive edge observability, then the position and orientation measurement precision is improved, but the processing load increases significantly

Engineering Contradiction:
Improveposition and orientation measurement precisionVSAvoidprocessing speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the edge detection process by dividing the two-dimensional image into multiple regions and detecting edges in each region separately. This allows comprehensive edge observability while reducing the processing load compared to detecting all edges from the entire image at once. The segmentation enables parallel processing and focuses computational resources on relevant areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different weights to different edges based on their reliability and observability characteristics. Edges with higher reliability and better observability across multiple view-points are given higher weights in the position and orientation calculation. This selective weighting improves measurement precision without requiring all edges to be processed equally, thus reducing overall processing load.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If edges are detected from the entire two-dimensional image to improve edge observability, then the position and orientation measurement precision is improved, but the processing load increases

Engineering Contradiction:
Improveposition and orientation measurement precisionVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the edge detection process by dividing the two-dimensional image into multiple regions and detecting edges in each region separately. This allows comprehensive edge observability while reducing the processing load compared to detecting all edges from the entire image at once. The segmentation enables parallel processing and focuses computational resources on relevant areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different weights to different edges based on their reliability and observability characteristics. Edges with higher reliability and better observability across multiple view-points are given higher weights in the position and orientation calculation. This selective weighting improves measurement precision without requiring all edges to be processed equally, thus reducing overall processing complexity.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If all edges are used in position/orientation calculation to maximize edge utilization, then the measurement precision is improved, but errors from background edges and unreliable edges increase

Engineering Contradiction:
Improveposition and orientation measurement precisionVSAvoidedge matching reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by assigning different weights to different edges based on their reliability and observability characteristics. Edges with higher reliability and better observability across multiple view-points are given higher weights in the position and orientation calculation. This selective weighting improves measurement precision while filtering out errors from background edges and unreliable edges, as they receive lower or zero weights.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent performs preliminary evaluation of edge reliability and observability before the position and orientation calculation. By pre-calculating weights for each edge based on their characteristics and performance across multiple view-points, the system prepares a filtered and weighted set of edges that are more likely to be accurate. This preliminary action prevents unreliable edges from degrading the measurement precision.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If a simple geometric model is used to reduce model complexity, then the processing load is reduced, but the ability to accurately represent the measurement object decreases

Engineering Contradiction:
Improveprocessing speedVSAvoidposition and orientation measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by assigning different weights to different edges based on their reliability and observability characteristics. Edges with higher reliability and better observability across multiple view-points are given higher weights in the position and orientation calculation. This selective weighting improves measurement precision without requiring all edges to be processed equally, thus reducing overall processing load.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9355453B2Three-dimensional measurement apparatus, model generation apparatus, processing method thereof, and non-transitory computer-readable storage medium
Publication Date: 2016.05.31 CANON KK
  • US9355453B2 patent drawing
  • US9355453B2 patent drawing
  • US9355453B2 patent drawing

AI summary

A three-dimensional measurement apparatus generates a plurality of view-point images obtained by observing a measurement object from a plurality of different view-points using a three-dimensional geometric model, detects edges of the measurement object from the plurality of view-point images as second edges, calculates respective reliabilities of first edges of the three-dimensional geometric model based on a result obtained when the second edges are associated with the first edges, weights each of the first edges based on the respective reliabilities, associates third edges detected from a captured image with the weighted first edges, and calculates a position and an orientation of the measurement object based on the association result.