Robot Relocation Using Weighted Boundary Complexity

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Solution Overview

Problem

Existing robot relocation methods, which rely on template matching or gradient matching, suffer from high false alarm rates due to the similarity of boundary information in 2D grid maps, particularly in long corridor areas or junctions with multiple walls, leading to inaccurate robot positioning and poor user experience.

Innovation Solution

A relocation method that sets matching weights for black boundaries based on their length and curve complexity, enhancing the impact of small objects and thin areas during relocation, thereby reducing false alarms and improving robustness without increasing hardware costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If template matching or gradient matching is used for robot relocation, then the relocation process can be completed, but the false alarm rate increases due to high similarity of boundary information in 2D grid maps

Engineering Contradiction:
Improverelocation process completionVSAvoidfalse alarm rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different boundary elements in the 2D grid map. Instead of treating all boundaries uniformly, the system identifies and emphasizes small boundaries and thin areas that provide unique localization cues, while reducing the weight of large boundaries that cause false alarms. This selective emphasis on specific local features resolves the contradiction by maintaining relocation capability while reducing false alarm rate.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of boundary weight assignment in the matching process. By introducing a weight mechanism that adjusts the importance of different boundary elements based on their characteristics (size, shape, complexity), the system transforms the matching process to be less sensitive to similar boundary information. This parameter change enables the system to maintain relocation functionality while significantly reducing false alarm rate.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If 2D grid maps are used to describe boundary information, then the map construction is simple, but the distinction between large areas and long borders becomes unclear leading to high false alarm rate

Engineering Contradiction:
Improvemap construction simplicityVSAvoidboundary distinction accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different boundary elements in the 2D grid map. Instead of treating all boundaries uniformly, the system identifies and emphasizes small boundaries and thin areas that provide unique localization cues, while reducing the weight of large boundaries that cause false alarms. This selective emphasis on specific local features resolves the contradiction by maintaining relocation capability while reducing false alarm rate.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the boundary information into different categories based on their characteristics (small boundaries, thin areas, long borders, large areas). By dividing the boundary information into distinct segments and applying different weighting strategies to each segment, the system improves the ability to distinguish between different boundary types while maintaining the simplicity of 2D grid map construction.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If matching weight is uniformly applied to all boundaries, then the computation is simple, but small objects and thin areas have insufficient impact on relocation accuracy

Engineering Contradiction:
Improvecomputation complexityVSAvoidrelocation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter of boundary weight assignment in the matching process. By introducing a weight mechanism that adjusts the importance of different boundary elements based on their characteristics (size, shape, complexity), the system transforms the matching process to be less sensitive to similar boundary information. This parameter change enables the system to maintain relocation functionality while significantly reducing false alarm rate.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by differentiating the treatment of different boundary elements in the 2D grid map. Instead of treating all boundaries uniformly, the system identifies and emphasizes small boundaries and thin areas that provide unique localization cues, while reducing the weight of large boundaries that cause false alarms. This selective emphasis on specific local features resolves the contradiction by maintaining relocation capability while reducing false alarm rate.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS11983916B2Relocation method, mobile machine using the same, and computer readable storage medium
Publication Date: 2024.05.14 UBTECH ROBOTICS CORP LTD
  • US11983916B2 patent drawing
  • US11983916B2 patent drawing
  • US11983916B2 patent drawing

AI summary

A relocation method and a mobile machine using the same are provided. The method includes: obtaining a global map and a current scan map of a target scene where a mobile machine is located, and generating a local sub-map based on the global map; obtaining a black boundary in the local sub-map, determining a length and a curve complexity of the black boundary, and determining a weight of the black boundary based on the length and the curve complexity of the black boundary; determining an estimated pose and a target black boundary based on the local sub-map and the current scan image, and obtaining a matching value between the current scan image and the local sub-map based on a weight of the target black boundary; and determining the estimated pose as a relocated pose of the mobile machine in response to the matching value being larger than a preset threshold.