Mobile Robot Localization With Local Maps and Smooth Map Switching

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Solution Overview

Problem

Existing mobile robot localization methods using 3D laser radar consume excessive memory and computation resources due to loading all point clouds at once, and lack transitions between maps, causing localization jitter during map switching.

Innovation Solution

A localization method for mobile robots that loads point clouds in blocks, utilizing multi-thread computation and dynamic key frame management to reduce memory consumption and improve operational efficiency by managing local maps with real-time updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all point clouds are loaded at a time after initialization, then localization completeness is improved, but memory space consumption increases excessively

Engineering Contradiction:
Improvelocalization completenessVSAvoidmemory space consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent divides the global map point clouds into multiple local maps, each covering a specific region. Only the current local map is loaded into memory for localization operations, while other regions remain stored on disk. This segmentation approach maintains localization completeness for the current region while dramatically reducing memory consumption compared to loading all point clouds simultaneously.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If point clouds are loaded in blocks without transition configuration, then memory consumption is reduced, but localization jitter occurs during map switching

Engineering Contradiction:
Improvememory consumptionVSAvoidlocalization stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent pre-configures transition regions between adjacent local maps during map construction. These transition regions contain overlapping point cloud data from neighboring areas. When the robot approaches a map boundary, the system proactively loads the next local map into memory using the current pose, ensuring a smooth transition without localization jitter. This preliminary preparation of transition data eliminates the instability that would otherwise occur during map switching.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If all key frames are retained for pose matching, then localization accuracy is improved, but computation resource consumption increases

Engineering Contradiction:
Improvelocalization accuracyVSAvoidcomputation resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts and retains only key frames from the complete point cloud data, discarding redundant intermediate frames. These key frames are strategically selected to represent important spatial locations and features. During pose matching, only these extracted key frames are used for comparison, maintaining localization accuracy while significantly reducing the computational burden of processing all original point cloud data.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If computation is performed using single-thread, then system simplicity is maintained, but operational efficiency decreases

Engineering Contradiction:
Improvesystem simplicityVSAvoidoperational efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements a dynamic multi-threaded computation architecture where the system automatically adjusts the number of threads based on operational conditions. During normal localization, multiple threads perform parallel operations such as point cloud registration, pose estimation, and map updates simultaneously. The system dynamically manages thread creation and termination based on computational load, maintaining high operational efficiency while adapting to varying system states and resource availability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS12479082B1Mobile robot, controller, and localization method for mobile robot
Publication Date: 2025.11.25 VISIONNAV ROBOTICS USA INC
  • US12479082B1 patent drawing
  • US12479082B1 patent drawing
  • US12479082B1 patent drawing

AI summary

Disclosed are a mobile robot, a controller, and a localization method for a mobile robot. The mobile robot includes a processor. The processor is configured to execute a program instruction so as to implement the following steps: determining, after the mobile robot is started up, whether the mobile robot operates in a first mode; loading a local map from a memory according to an initial position of the mobile robot in response to the mobile robot operating in the first mode; conducting pose matching according to a current position point cloud based on the local map, and outputting a current pose; determining, according to the current pose, whether a key frame corresponding to the local map is changed; and outputting a current position of the mobile robot in response to the key frame corresponding to the local map being unchanged.